Commit Graph

212 Commits

Author SHA1 Message Date
Linus Torvalds
7001052160 Add support for Intel CET-IBT, available since Tigerlake (11th gen), which is a
coarse grained, hardware based, forward edge Control-Flow-Integrity mechanism
 where any indirect CALL/JMP must target an ENDBR instruction or suffer #CP.
 
 Additionally, since Alderlake (12th gen)/Sapphire-Rapids, speculation is
 limited to 2 instructions (and typically fewer) on branch targets not starting
 with ENDBR. CET-IBT also limits speculation of the next sequential instruction
 after the indirect CALL/JMP [1].
 
 CET-IBT is fundamentally incompatible with retpolines, but provides, as
 described above, speculation limits itself.
 
 [1] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html
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Merge tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 CET-IBT (Control-Flow-Integrity) support from Peter Zijlstra:
 "Add support for Intel CET-IBT, available since Tigerlake (11th gen),
  which is a coarse grained, hardware based, forward edge
  Control-Flow-Integrity mechanism where any indirect CALL/JMP must
  target an ENDBR instruction or suffer #CP.

  Additionally, since Alderlake (12th gen)/Sapphire-Rapids, speculation
  is limited to 2 instructions (and typically fewer) on branch targets
  not starting with ENDBR. CET-IBT also limits speculation of the next
  sequential instruction after the indirect CALL/JMP [1].

  CET-IBT is fundamentally incompatible with retpolines, but provides,
  as described above, speculation limits itself"

[1] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html

* tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  kvm/emulate: Fix SETcc emulation for ENDBR
  x86/Kconfig: Only allow CONFIG_X86_KERNEL_IBT with ld.lld >= 14.0.0
  x86/Kconfig: Only enable CONFIG_CC_HAS_IBT for clang >= 14.0.0
  kbuild: Fixup the IBT kbuild changes
  x86/Kconfig: Do not allow CONFIG_X86_X32_ABI=y with llvm-objcopy
  x86: Remove toolchain check for X32 ABI capability
  x86/alternative: Use .ibt_endbr_seal to seal indirect calls
  objtool: Find unused ENDBR instructions
  objtool: Validate IBT assumptions
  objtool: Add IBT/ENDBR decoding
  objtool: Read the NOENDBR annotation
  x86: Annotate idtentry_df()
  x86,objtool: Move the ASM_REACHABLE annotation to objtool.h
  x86: Annotate call_on_stack()
  objtool: Rework ASM_REACHABLE
  x86: Mark __invalid_creds() __noreturn
  exit: Mark do_group_exit() __noreturn
  x86: Mark stop_this_cpu() __noreturn
  objtool: Ignore extra-symbol code
  objtool: Rename --duplicate to --lto
  ...
2022-03-27 10:17:23 -07:00
Jakub Kicinski
0db8640df5 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2022-03-21 v2

We've added 137 non-merge commits during the last 17 day(s) which contain
a total of 143 files changed, 7123 insertions(+), 1092 deletions(-).

The main changes are:

1) Custom SEC() handling in libbpf, from Andrii.

2) subskeleton support, from Delyan.

3) Use btf_tag to recognize __percpu pointers in the verifier, from Hao.

4) Fix net.core.bpf_jit_harden race, from Hou.

5) Fix bpf_sk_lookup remote_port on big-endian, from Jakub.

6) Introduce fprobe (multi kprobe) _without_ arch bits, from Masami.
The arch specific bits will come later.

7) Introduce multi_kprobe bpf programs on top of fprobe, from Jiri.

8) Enable non-atomic allocations in local storage, from Joanne.

9) Various var_off ptr_to_btf_id fixed, from Kumar.

10) bpf_ima_file_hash helper, from Roberto.

11) Add "live packet" mode for XDP in BPF_PROG_RUN, from Toke.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (137 commits)
  selftests/bpf: Fix kprobe_multi test.
  Revert "rethook: x86: Add rethook x86 implementation"
  Revert "arm64: rethook: Add arm64 rethook implementation"
  Revert "powerpc: Add rethook support"
  Revert "ARM: rethook: Add rethook arm implementation"
  bpftool: Fix a bug in subskeleton code generation
  bpf: Fix bpf_prog_pack when PMU_SIZE is not defined
  bpf: Fix bpf_prog_pack for multi-node setup
  bpf: Fix warning for cast from restricted gfp_t in verifier
  bpf, arm: Fix various typos in comments
  libbpf: Close fd in bpf_object__reuse_map
  bpftool: Fix print error when show bpf map
  bpf: Fix kprobe_multi return probe backtrace
  Revert "bpf: Add support to inline bpf_get_func_ip helper on x86"
  bpf: Simplify check in btf_parse_hdr()
  selftests/bpf/test_lirc_mode2.sh: Exit with proper code
  bpf: Check for NULL return from bpf_get_btf_vmlinux
  selftests/bpf: Test skipping stacktrace
  bpf: Adjust BPF stack helper functions to accommodate skip > 0
  bpf: Select proper size for bpf_prog_pack
  ...
====================

Link: https://lore.kernel.org/r/20220322050159.5507-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-22 11:18:49 -07:00
Hou Tao
73e14451f3 bpf, x86: Fall back to interpreter mode when extra pass fails
Extra pass for subprog jit may fail (e.g. due to bpf_jit_harden race),
but bpf_func is not cleared for the subprog and jit_subprogs will
succeed. The running of the bpf program may lead to oops because the
memory for the jited subprog image has already been freed.

So fall back to interpreter mode by clearing bpf_func/jited/jited_len
when extra pass fails.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220309123321.2400262-2-houtao1@huawei.com
2022-03-16 15:12:18 -07:00
Peter Zijlstra
5891271055 x86/ibt,bpf: Add ENDBR instructions to prologue and trampoline
With IBT enabled builds we need ENDBR instructions at indirect jump
target sites, since we start execution of the JIT'ed code through an
indirect jump, the very first instruction needs to be ENDBR.

Similarly, since eBPF tail-calls use indirect branches, their landing
site needs to be an ENDBR too.

The trampolines need similar adjustment.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Fixed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154318.464998838@infradead.org
2022-03-15 10:32:38 +01:00
Jakub Kicinski
1e8a3f0d2a Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
net/dsa/dsa2.c
  commit afb3cc1a39 ("net: dsa: unlock the rtnl_mutex when dsa_master_setup() fails")
  commit e83d565378 ("net: dsa: replay master state events in dsa_tree_{setup,teardown}_master")
https://lore.kernel.org/all/20220307101436.7ae87da0@canb.auug.org.au/

drivers/net/ethernet/intel/ice/ice.h
  commit 97b0129146 ("ice: Fix error with handling of bonding MTU")
  commit 43113ff734 ("ice: add TTY for GNSS module for E810T device")
https://lore.kernel.org/all/20220310112843.3233bcf1@canb.auug.org.au/

drivers/staging/gdm724x/gdm_lte.c
  commit fc7f750dc9 ("staging: gdm724x: fix use after free in gdm_lte_rx()")
  commit 4bcc4249b4 ("staging: Use netif_rx().")
https://lore.kernel.org/all/20220308111043.1018a59d@canb.auug.org.au/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-10 17:16:56 -08:00
Song Liu
676b2daaba bpf, x86: Set header->size properly before freeing it
On do_jit failure path, the header is freed by bpf_jit_binary_pack_free.
While bpf_jit_binary_pack_free doesn't require proper ro_header->size,
bpf_prog_pack_free still uses it. Set header->size in bpf_int_jit_compile
before calling bpf_jit_binary_pack_free.

Fixes: 1022a5498f ("bpf, x86_64: Use bpf_jit_binary_pack_alloc")
Fixes: 33c9805860 ("bpf: Introduce bpf_jit_binary_pack_[alloc|finalize|free]")
Reported-by: Kui-Feng Lee <kuifeng@fb.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220302175126.247459-3-song@kernel.org
2022-03-02 13:24:37 -08:00
Peter Zijlstra (Intel)
d45476d983 x86/speculation: Rename RETPOLINE_AMD to RETPOLINE_LFENCE
The RETPOLINE_AMD name is unfortunate since it isn't necessarily
AMD only, in fact Hygon also uses it. Furthermore it will likely be
sufficient for some Intel processors. Therefore rename the thing to
RETPOLINE_LFENCE to better describe what it is.

Add the spectre_v2=retpoline,lfence option as an alias to
spectre_v2=retpoline,amd to preserve existing setups. However, the output
of /sys/devices/system/cpu/vulnerabilities/spectre_v2 will be changed.

  [ bp: Fix typos, massage. ]

Co-developed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2022-02-21 10:21:28 +01:00
Song Liu
f95f768f0a bpf, x86_64: Fail gracefully on bpf_jit_binary_pack_finalize failures
Instead of BUG_ON(), fail gracefully and return orig_prog.

Fixes: 1022a5498f ("bpf, x86_64: Use bpf_jit_binary_pack_alloc")
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220208062533.3802081-1-song@kernel.org
2022-02-08 09:23:18 -08:00
Song Liu
1022a5498f bpf, x86_64: Use bpf_jit_binary_pack_alloc
Use bpf_jit_binary_pack_alloc in x86_64 jit. The jit engine first writes
the program to the rw buffer. When the jit is done, the program is copied
to the final location with bpf_jit_binary_pack_finalize.

Note that we need to do bpf_tail_call_direct_fixup after finalize.
Therefore, the text_live = false logic in __bpf_arch_text_poke is no
longer needed.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220204185742.271030-10-song@kernel.org
2022-02-07 18:13:01 -08:00
Song Liu
ebc1415d9b bpf: Introduce bpf_arch_text_copy
This will be used to copy JITed text to RO protected module memory. On
x86, bpf_arch_text_copy is implemented with text_poke_copy.

bpf_arch_text_copy returns pointer to dst on success, and ERR_PTR(errno)
on errors.

Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220204185742.271030-7-song@kernel.org
2022-02-07 18:13:01 -08:00
Hou Tao
b6ec79518e bpf, x86: Remove unnecessary handling of BPF_SUB atomic op
According to the LLVM commit (https://reviews.llvm.org/D72184),
sync_fetch_and_sub() is implemented as a negation followed by
sync_fetch_and_add(), so there will be no BPF_SUB op, thus just
remove it. BPF_SUB is also rejected by the verifier anyway.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Brendan Jackman <jackmanb@google.com>
Link: https://lore.kernel.org/bpf/20220127083240.1425481-1-houtao1@huawei.com
2022-01-27 22:47:05 +01:00
Linus Torvalds
64ad946152 - Get rid of all the .fixup sections because this generates
misleading/wrong stacktraces and confuse RELIABLE_STACKTRACE and
 LIVEPATCH as the backtrace misses the function which is being fixed up.
 
 - Add Straight Light Speculation mitigation support which uses a new
 compiler switch -mharden-sls= which sticks an INT3 after a RET or an
 indirect branch in order to block speculation after them. Reportedly,
 CPUs do speculate behind such insns.
 
 - The usual set of cleanups and improvements
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Merge tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 core updates from Borislav Petkov:

 - Get rid of all the .fixup sections because this generates
   misleading/wrong stacktraces and confuse RELIABLE_STACKTRACE and
   LIVEPATCH as the backtrace misses the function which is being fixed
   up.

 - Add Straight Line Speculation mitigation support which uses a new
   compiler switch -mharden-sls= which sticks an INT3 after a RET or an
   indirect branch in order to block speculation after them. Reportedly,
   CPUs do speculate behind such insns.

 - The usual set of cleanups and improvements

* tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  x86/entry_32: Fix segment exceptions
  objtool: Remove .fixup handling
  x86: Remove .fixup section
  x86/word-at-a-time: Remove .fixup usage
  x86/usercopy: Remove .fixup usage
  x86/usercopy_32: Simplify __copy_user_intel_nocache()
  x86/sgx: Remove .fixup usage
  x86/checksum_32: Remove .fixup usage
  x86/vmx: Remove .fixup usage
  x86/kvm: Remove .fixup usage
  x86/segment: Remove .fixup usage
  x86/fpu: Remove .fixup usage
  x86/xen: Remove .fixup usage
  x86/uaccess: Remove .fixup usage
  x86/futex: Remove .fixup usage
  x86/msr: Remove .fixup usage
  x86/extable: Extend extable functionality
  x86/entry_32: Remove .fixup usage
  x86/entry_64: Remove .fixup usage
  x86/copy_mc_64: Remove .fixup usage
  ...
2022-01-12 16:31:19 -08:00
David S. Miller
e63a023489 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-12-30

The following pull-request contains BPF updates for your *net-next* tree.

We've added 72 non-merge commits during the last 20 day(s) which contain
a total of 223 files changed, 3510 insertions(+), 1591 deletions(-).

The main changes are:

1) Automatic setrlimit in libbpf when bpf is memcg's in the kernel, from Andrii.

2) Beautify and de-verbose verifier logs, from Christy.

3) Composable verifier types, from Hao.

4) bpf_strncmp helper, from Hou.

5) bpf.h header dependency cleanup, from Jakub.

6) get_func_[arg|ret|arg_cnt] helpers, from Jiri.

7) Sleepable local storage, from KP.

8) Extend kfunc with PTR_TO_CTX, PTR_TO_MEM argument support, from Kumar.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-31 14:35:40 +00:00
Jakub Kicinski
7cd2802d74 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
No conflicts.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-16 16:13:19 -08:00
Alexei Starovoitov
588a25e924 bpf: Fix extable address check.
The verifier checks that PTR_TO_BTF_ID pointer is either valid or NULL,
but it cannot distinguish IS_ERR pointer from valid one.

When offset is added to IS_ERR pointer it may become small positive
value which is a user address that is not handled by extable logic
and has to be checked for at the runtime.

Tighten BPF_PROBE_MEM pointer check code to prevent this case.

Fixes: 4c5de12759 ("bpf: Emit explicit NULL pointer checks for PROBE_LDX instructions.")
Reported-by: Lorenzo Fontana <lorenzo.fontana@elastic.co>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2021-12-16 21:41:04 +01:00
Alexei Starovoitov
433956e912 bpf: Fix extable fixup offset.
The prog - start_of_ldx is the offset before the faulting ldx to the location
after it, so this will be used to adjust pt_regs->ip for jumping over it and
continuing, and with old temp it would have been fixed up to the wrong offset,
causing crash.

Fixes: 4c5de12759 ("bpf: Emit explicit NULL pointer checks for PROBE_LDX instructions.")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2021-12-16 21:18:26 +01:00
Jiri Olsa
f92c1e1836 bpf: Add get_func_[arg|ret|arg_cnt] helpers
Adding following helpers for tracing programs:

Get n-th argument of the traced function:
  long bpf_get_func_arg(void *ctx, u32 n, u64 *value)

Get return value of the traced function:
  long bpf_get_func_ret(void *ctx, u64 *value)

Get arguments count of the traced function:
  long bpf_get_func_arg_cnt(void *ctx)

The trampoline now stores number of arguments on ctx-8
address, so it's easy to verify argument index and find
return value argument's position.

Moving function ip address on the trampoline stack behind
the number of functions arguments, so it's now stored on
ctx-16 address if it's needed.

All helpers above are inlined by verifier.

Also bit unrelated small change - using newly added function
bpf_prog_has_trampoline in check_get_func_ip.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211208193245.172141-5-jolsa@kernel.org
2021-12-13 09:25:59 -08:00
Jiri Olsa
5edf6a1983 bpf, x64: Replace some stack_size usage with offset variables
As suggested by Andrii, adding variables for registers and ip
address offsets, which makes the code more clear, rather than
abusing single stack_size variable for everything.

Also describing the stack layout in the comment.

There is no function change.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211208193245.172141-4-jolsa@kernel.org
2021-12-13 09:24:22 -08:00
Peter Zijlstra
4b5305decc x86/extable: Extend extable functionality
In order to remove further .fixup usage, extend the extable
infrastructure to take additional information from the extable entry
sites.

Specifically add _ASM_EXTABLE_TYPE_REG() and EX_TYPE_IMM_REG that
extend the existing _ASM_EXTABLE_TYPE() by taking an additional
register argument and encoding that and an s16 immediate into the
existing s32 type field. This limits the actual types to the first
byte, 255 seem plenty.

Also add a few flags into the type word, specifically CLEAR_AX and
CLEAR_DX which clear the return and extended return register.

Notes:
 - due to the % in our register names it's hard to make it more
   generally usable as arm64 did.
 - the s16 is far larger than used in these patches, future extentions
   can easily shrink this to get more bits.
 - without the bitfield fix this will not compile, because: 0xFF > -1
   and we can't even extract the TYPE field.

[nathanchance: Build fix for clang-lto builds:
 https://lkml.kernel.org/r/20211210234953.3420108-1-nathan@kernel.org
]

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20211110101325.303890153@infradead.org
2021-12-11 09:09:46 +01:00
Christoph Hellwig
58ffa1b413 x86, bpf: Cleanup the top of file header in bpf_jit_comp.c
Don't bother mentioning the file name as it is implied, and remove the
reference to internal BPF.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211119163215.971383-2-hch@lst.de
2021-11-30 10:52:11 -08:00
Tiezhu Yang
ebf7f6f0a6 bpf: Change value of MAX_TAIL_CALL_CNT from 32 to 33
In the current code, the actual max tail call count is 33 which is greater
than MAX_TAIL_CALL_CNT (defined as 32). The actual limit is not consistent
with the meaning of MAX_TAIL_CALL_CNT and thus confusing at first glance.
We can see the historical evolution from commit 04fd61ab36 ("bpf: allow
bpf programs to tail-call other bpf programs") and commit f9dabe016b
("bpf: Undo off-by-one in interpreter tail call count limit"). In order
to avoid changing existing behavior, the actual limit is 33 now, this is
reasonable.

After commit 874be05f52 ("bpf, tests: Add tail call test suite"), we can
see there exists failed testcase.

On all archs when CONFIG_BPF_JIT_ALWAYS_ON is not set:
 # echo 0 > /proc/sys/net/core/bpf_jit_enable
 # modprobe test_bpf
 # dmesg | grep -w FAIL
 Tail call error path, max count reached jited:0 ret 34 != 33 FAIL

On some archs:
 # echo 1 > /proc/sys/net/core/bpf_jit_enable
 # modprobe test_bpf
 # dmesg | grep -w FAIL
 Tail call error path, max count reached jited:1 ret 34 != 33 FAIL

Although the above failed testcase has been fixed in commit 18935a72eb
("bpf/tests: Fix error in tail call limit tests"), it would still be good
to change the value of MAX_TAIL_CALL_CNT from 32 to 33 to make the code
more readable.

The 32-bit x86 JIT was using a limit of 32, just fix the wrong comments and
limit to 33 tail calls as the constant MAX_TAIL_CALL_CNT updated. For the
mips64 JIT, use "ori" instead of "addiu" as suggested by Johan Almbladh.
For the riscv JIT, use RV_REG_TCC directly to save one register move as
suggested by Björn Töpel. For the other implementations, no function changes,
it does not change the current limit 33, the new value of MAX_TAIL_CALL_CNT
can reflect the actual max tail call count, the related tail call testcases
in test_bpf module and selftests can work well for the interpreter and the
JIT.

Here are the test results on x86_64:

 # uname -m
 x86_64
 # echo 0 > /proc/sys/net/core/bpf_jit_enable
 # modprobe test_bpf test_suite=test_tail_calls
 # dmesg | tail -1
 test_bpf: test_tail_calls: Summary: 8 PASSED, 0 FAILED, [0/8 JIT'ed]
 # rmmod test_bpf
 # echo 1 > /proc/sys/net/core/bpf_jit_enable
 # modprobe test_bpf test_suite=test_tail_calls
 # dmesg | tail -1
 test_bpf: test_tail_calls: Summary: 8 PASSED, 0 FAILED, [8/8 JIT'ed]
 # rmmod test_bpf
 # ./test_progs -t tailcalls
 #142 tailcalls:OK
 Summary: 1/11 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Björn Töpel <bjorn@kernel.org>
Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/bpf/1636075800-3264-1-git-send-email-yangtiezhu@loongson.cn
2021-11-16 14:03:15 +01:00
Linus Torvalds
fc02cb2b37 Core:
- Remove socket skb caches
 
  - Add a SO_RESERVE_MEM socket op to forward allocate buffer space
    and avoid memory accounting overhead on each message sent
 
  - Introduce managed neighbor entries - added by control plane and
    resolved by the kernel for use in acceleration paths (BPF / XDP
    right now, HW offload users will benefit as well)
 
  - Make neighbor eviction on link down controllable by userspace
    to work around WiFi networks with bad roaming implementations
 
  - vrf: Rework interaction with netfilter/conntrack
 
  - fq_codel: implement L4S style ce_threshold_ect1 marking
 
  - sch: Eliminate unnecessary RCU waits in mini_qdisc_pair_swap()
 
 BPF:
 
  - Add support for new btf kind BTF_KIND_TAG, arbitrary type tagging
    as implemented in LLVM14
 
  - Introduce bpf_get_branch_snapshot() to capture Last Branch Records
 
  - Implement variadic trace_printk helper
 
  - Add a new Bloomfilter map type
 
  - Track <8-byte scalar spill and refill
 
  - Access hw timestamp through BPF's __sk_buff
 
  - Disallow unprivileged BPF by default
 
  - Document BPF licensing
 
 Netfilter:
 
  - Introduce egress hook for looking at raw outgoing packets
 
  - Allow matching on and modifying inner headers / payload data
 
  - Add NFT_META_IFTYPE to match on the interface type either from
    ingress or egress
 
 Protocols:
 
  - Multi-Path TCP:
    - increase default max additional subflows to 2
    - rework forward memory allocation
    - add getsockopts: MPTCP_INFO, MPTCP_TCPINFO, MPTCP_SUBFLOW_ADDRS
 
  - MCTP flow support allowing lower layer drivers to configure msg
    muxing as needed
 
  - Automatic Multicast Tunneling (AMT) driver based on RFC7450
 
  - HSR support the redbox supervision frames (IEC-62439-3:2018)
 
  - Support for the ip6ip6 encapsulation of IOAM
 
  - Netlink interface for CAN-FD's Transmitter Delay Compensation
 
  - Support SMC-Rv2 eliminating the current same-subnet restriction,
    by exploiting the UDP encapsulation feature of RoCE adapters
 
  - TLS: add SM4 GCM/CCM crypto support
 
  - Bluetooth: initial support for link quality and audio/codec
    offload
 
 Driver APIs:
 
  - Add a batched interface for RX buffer allocation in AF_XDP
    buffer pool
 
  - ethtool: Add ability to control transceiver modules' power mode
 
  - phy: Introduce supported interfaces bitmap to express MAC
    capabilities and simplify PHY code
 
  - Drop rtnl_lock from DSA .port_fdb_{add,del} callbacks
 
 New drivers:
 
  - WiFi driver for Realtek 8852AE 802.11ax devices (rtw89)
 
  - Ethernet driver for ASIX AX88796C SPI device (x88796c)
 
 Drivers:
 
  - Broadcom PHYs
    - support 72165, 7712 16nm PHYs
    - support IDDQ-SR for additional power savings
 
  - PHY support for QCA8081, QCA9561 PHYs
 
  - NXP DPAA2: support for IRQ coalescing
 
  - NXP Ethernet (enetc): support for software TCP segmentation
 
  - Renesas Ethernet (ravb) - support DMAC and EMAC blocks of
    Gigabit-capable IP found on RZ/G2L SoC
 
  - Intel 100G Ethernet
    - support for eswitch offload of TC/OvS flow API, including
      offload of GRE, VxLAN, Geneve tunneling
    - support application device queues - ability to assign Rx and Tx
      queues to application threads
    - PTP and PPS (pulse-per-second) extensions
 
  - Broadcom Ethernet (bnxt)
    - devlink health reporting and device reload extensions
 
  - Mellanox Ethernet (mlx5)
    - offload macvlan interfaces
    - support HW offload of TC rules involving OVS internal ports
    - support HW-GRO and header/data split
    - support application device queues
 
  - Marvell OcteonTx2:
    - add XDP support for PF
    - add PTP support for VF
 
  - Qualcomm Ethernet switch (qca8k): support for QCA8328
 
  - Realtek Ethernet DSA switch (rtl8366rb)
    - support bridge offload
    - support STP, fast aging, disabling address learning
    - support for Realtek RTL8365MB-VC, a 4+1 port 10M/100M/1GE switch
 
  - Mellanox Ethernet/IB switch (mlxsw)
    - multi-level qdisc hierarchy offload (e.g. RED, prio and shaping)
    - offload root TBF qdisc as port shaper
    - support multiple routing interface MAC address prefixes
    - support for IP-in-IP with IPv6 underlay
 
  - MediaTek WiFi (mt76)
    - mt7921 - ASPM, 6GHz, SDIO and testmode support
    - mt7915 - LED and TWT support
 
  - Qualcomm WiFi (ath11k)
    - include channel rx and tx time in survey dump statistics
    - support for 80P80 and 160 MHz bandwidths
    - support channel 2 in 6 GHz band
    - spectral scan support for QCN9074
    - support for rx decapsulation offload (data frames in 802.3
      format)
 
  - Qualcomm phone SoC WiFi (wcn36xx)
    - enable Idle Mode Power Save (IMPS) to reduce power consumption
      during idle
 
  - Bluetooth driver support for MediaTek MT7922 and MT7921
 
  - Enable support for AOSP Bluetooth extension in Qualcomm WCN399x
    and Realtek 8822C/8852A
 
  - Microsoft vNIC driver (mana)
    - support hibernation and kexec
 
  - Google vNIC driver (gve)
    - support for jumbo frames
    - implement Rx page reuse
 
 Refactor:
 
  - Make all writes to netdev->dev_addr go thru helpers, so that we
    can add this address to the address rbtree and handle the updates
 
  - Various TCP cleanups and optimizations including improvements
    to CPU cache use
 
  - Simplify the gnet_stats, Qdisc stats' handling and remove
    qdisc->running sequence counter
 
  - Driver changes and API updates to address devlink locking
    deficiencies
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core:

   - Remove socket skb caches

   - Add a SO_RESERVE_MEM socket op to forward allocate buffer space and
     avoid memory accounting overhead on each message sent

   - Introduce managed neighbor entries - added by control plane and
     resolved by the kernel for use in acceleration paths (BPF / XDP
     right now, HW offload users will benefit as well)

   - Make neighbor eviction on link down controllable by userspace to
     work around WiFi networks with bad roaming implementations

   - vrf: Rework interaction with netfilter/conntrack

   - fq_codel: implement L4S style ce_threshold_ect1 marking

   - sch: Eliminate unnecessary RCU waits in mini_qdisc_pair_swap()

  BPF:

   - Add support for new btf kind BTF_KIND_TAG, arbitrary type tagging
     as implemented in LLVM14

   - Introduce bpf_get_branch_snapshot() to capture Last Branch Records

   - Implement variadic trace_printk helper

   - Add a new Bloomfilter map type

   - Track <8-byte scalar spill and refill

   - Access hw timestamp through BPF's __sk_buff

   - Disallow unprivileged BPF by default

   - Document BPF licensing

  Netfilter:

   - Introduce egress hook for looking at raw outgoing packets

   - Allow matching on and modifying inner headers / payload data

   - Add NFT_META_IFTYPE to match on the interface type either from
     ingress or egress

  Protocols:

   - Multi-Path TCP:
      - increase default max additional subflows to 2
      - rework forward memory allocation
      - add getsockopts: MPTCP_INFO, MPTCP_TCPINFO, MPTCP_SUBFLOW_ADDRS

   - MCTP flow support allowing lower layer drivers to configure msg
     muxing as needed

   - Automatic Multicast Tunneling (AMT) driver based on RFC7450

   - HSR support the redbox supervision frames (IEC-62439-3:2018)

   - Support for the ip6ip6 encapsulation of IOAM

   - Netlink interface for CAN-FD's Transmitter Delay Compensation

   - Support SMC-Rv2 eliminating the current same-subnet restriction, by
     exploiting the UDP encapsulation feature of RoCE adapters

   - TLS: add SM4 GCM/CCM crypto support

   - Bluetooth: initial support for link quality and audio/codec offload

  Driver APIs:

   - Add a batched interface for RX buffer allocation in AF_XDP buffer
     pool

   - ethtool: Add ability to control transceiver modules' power mode

   - phy: Introduce supported interfaces bitmap to express MAC
     capabilities and simplify PHY code

   - Drop rtnl_lock from DSA .port_fdb_{add,del} callbacks

  New drivers:

   - WiFi driver for Realtek 8852AE 802.11ax devices (rtw89)

   - Ethernet driver for ASIX AX88796C SPI device (x88796c)

  Drivers:

   - Broadcom PHYs
      - support 72165, 7712 16nm PHYs
      - support IDDQ-SR for additional power savings

   - PHY support for QCA8081, QCA9561 PHYs

   - NXP DPAA2: support for IRQ coalescing

   - NXP Ethernet (enetc): support for software TCP segmentation

   - Renesas Ethernet (ravb) - support DMAC and EMAC blocks of
     Gigabit-capable IP found on RZ/G2L SoC

   - Intel 100G Ethernet
      - support for eswitch offload of TC/OvS flow API, including
        offload of GRE, VxLAN, Geneve tunneling
      - support application device queues - ability to assign Rx and Tx
        queues to application threads
      - PTP and PPS (pulse-per-second) extensions

   - Broadcom Ethernet (bnxt)
      - devlink health reporting and device reload extensions

   - Mellanox Ethernet (mlx5)
      - offload macvlan interfaces
      - support HW offload of TC rules involving OVS internal ports
      - support HW-GRO and header/data split
      - support application device queues

   - Marvell OcteonTx2:
      - add XDP support for PF
      - add PTP support for VF

   - Qualcomm Ethernet switch (qca8k): support for QCA8328

   - Realtek Ethernet DSA switch (rtl8366rb)
      - support bridge offload
      - support STP, fast aging, disabling address learning
      - support for Realtek RTL8365MB-VC, a 4+1 port 10M/100M/1GE switch

   - Mellanox Ethernet/IB switch (mlxsw)
      - multi-level qdisc hierarchy offload (e.g. RED, prio and shaping)
      - offload root TBF qdisc as port shaper
      - support multiple routing interface MAC address prefixes
      - support for IP-in-IP with IPv6 underlay

   - MediaTek WiFi (mt76)
      - mt7921 - ASPM, 6GHz, SDIO and testmode support
      - mt7915 - LED and TWT support

   - Qualcomm WiFi (ath11k)
      - include channel rx and tx time in survey dump statistics
      - support for 80P80 and 160 MHz bandwidths
      - support channel 2 in 6 GHz band
      - spectral scan support for QCN9074
      - support for rx decapsulation offload (data frames in 802.3
        format)

   - Qualcomm phone SoC WiFi (wcn36xx)
      - enable Idle Mode Power Save (IMPS) to reduce power consumption
        during idle

   - Bluetooth driver support for MediaTek MT7922 and MT7921

   - Enable support for AOSP Bluetooth extension in Qualcomm WCN399x and
     Realtek 8822C/8852A

   - Microsoft vNIC driver (mana)
      - support hibernation and kexec

   - Google vNIC driver (gve)
      - support for jumbo frames
      - implement Rx page reuse

  Refactor:

   - Make all writes to netdev->dev_addr go thru helpers, so that we can
     add this address to the address rbtree and handle the updates

   - Various TCP cleanups and optimizations including improvements to
     CPU cache use

   - Simplify the gnet_stats, Qdisc stats' handling and remove
     qdisc->running sequence counter

   - Driver changes and API updates to address devlink locking
     deficiencies"

* tag 'net-next-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2122 commits)
  Revert "net: avoid double accounting for pure zerocopy skbs"
  selftests: net: add arp_ndisc_evict_nocarrier
  net: ndisc: introduce ndisc_evict_nocarrier sysctl parameter
  net: arp: introduce arp_evict_nocarrier sysctl parameter
  libbpf: Deprecate AF_XDP support
  kbuild: Unify options for BTF generation for vmlinux and modules
  selftests/bpf: Add a testcase for 64-bit bounds propagation issue.
  bpf: Fix propagation of signed bounds from 64-bit min/max into 32-bit.
  bpf: Fix propagation of bounds from 64-bit min/max into 32-bit and var_off.
  net: vmxnet3: remove multiple false checks in vmxnet3_ethtool.c
  net: avoid double accounting for pure zerocopy skbs
  tcp: rename sk_wmem_free_skb
  netdevsim: fix uninit value in nsim_drv_configure_vfs()
  selftests/bpf: Fix also no-alu32 strobemeta selftest
  bpf: Add missing map_delete_elem method to bloom filter map
  selftests/bpf: Add bloom map success test for userspace calls
  bpf: Add alignment padding for "map_extra" + consolidate holes
  bpf: Bloom filter map naming fixups
  selftests/bpf: Add test cases for struct_ops prog
  bpf: Add dummy BPF STRUCT_OPS for test purpose
  ...
2021-11-02 06:20:58 -07:00
Linus Torvalds
8cb1ae19bf x86/fpu updates:
- Cleanup of extable fixup handling to be more robust, which in turn
    allows to make the FPU exception fixups more robust as well.
 
  - Change the return code for signal frame related failures from explicit
    error codes to a boolean fail/success as that's all what the calling
    code evaluates.
 
  - A large refactoring of the FPU code to prepare for adding AMX support:
 
    - Distangle the public header maze and remove especially the misnomed
      kitchen sink internal.h which is despite it's name included all over
      the place.
 
    - Add a proper abstraction for the register buffer storage (struct
      fpstate) which allows to dynamically size the buffer at runtime by
      flipping the pointer to the buffer container from the default
      container which is embedded in task_struct::tread::fpu to a
      dynamically allocated container with a larger register buffer.
 
    - Convert the code over to the new fpstate mechanism.
 
    - Consolidate the KVM FPU handling by moving the FPU related code into
      the FPU core which removes the number of exports and avoids adding
      even more export when AMX has to be supported in KVM. This also
      removes duplicated code which was of course unnecessary different and
      incomplete in the KVM copy.
 
    - Simplify the KVM FPU buffer handling by utilizing the new fpstate
      container and just switching the buffer pointer from the user space
      buffer to the KVM guest buffer when entering vcpu_run() and flipping
      it back when leaving the function. This cuts the memory requirements
      of a vCPU for FPU buffers in half and avoids pointless memory copy
      operations.
 
      This also solves the so far unresolved problem of adding AMX support
      because the current FPU buffer handling of KVM inflicted a circular
      dependency between adding AMX support to the core and to KVM.  With
      the new scheme of switching fpstate AMX support can be added to the
      core code without affecting KVM.
 
    - Replace various variables with proper data structures so the extra
      information required for adding dynamically enabled FPU features (AMX)
      can be added in one place
 
  - Add AMX (Advanved Matrix eXtensions) support (finally):
 
     AMX is a large XSTATE component which is going to be available with
     Saphire Rapids XEON CPUs. The feature comes with an extra MSR (MSR_XFD)
     which allows to trap the (first) use of an AMX related instruction,
     which has two benefits:
 
     1) It allows the kernel to control access to the feature
 
     2) It allows the kernel to dynamically allocate the large register
        state buffer instead of burdening every task with the the extra 8K
        or larger state storage.
 
     It would have been great to gain this kind of control already with
     AVX512.
 
     The support comes with the following infrastructure components:
 
     1) arch_prctl() to
        - read the supported features (equivalent to XGETBV(0))
        - read the permitted features for a task
        - request permission for a dynamically enabled feature
 
        Permission is granted per process, inherited on fork() and cleared
        on exec(). The permission policy of the kernel is restricted to
        sigaltstack size validation, but the syscall obviously allows
        further restrictions via seccomp etc.
 
     2) A stronger sigaltstack size validation for sys_sigaltstack(2) which
        takes granted permissions and the potentially resulting larger
        signal frame into account. This mechanism can also be used to
        enforce factual sigaltstack validation independent of dynamic
        features to help with finding potential victims of the 2K
        sigaltstack size constant which is broken since AVX512 support was
        added.
 
     3) Exception handling for #NM traps to catch first use of a extended
        feature via a new cause MSR. If the exception was caused by the use
        of such a feature, the handler checks permission for that
        feature. If permission has not been granted, the handler sends a
        SIGILL like the #UD handler would do if the feature would have been
        disabled in XCR0. If permission has been granted, then a new fpstate
        which fits the larger buffer requirement is allocated.
 
        In the unlikely case that this allocation fails, the handler sends
        SIGSEGV to the task. That's not elegant, but unavoidable as the
        other discussed options of preallocation or full per task
        permissions come with their own set of horrors for kernel and/or
        userspace. So this is the lesser of the evils and SIGSEGV caused by
        unexpected memory allocation failures is not a fundamentally new
        concept either.
 
        When allocation succeeds, the fpstate properties are filled in to
        reflect the extended feature set and the resulting sizes, the
        fpu::fpstate pointer is updated accordingly and the trap is disarmed
        for this task permanently.
 
     4) Enumeration and size calculations
 
     5) Trap switching via MSR_XFD
 
        The XFD (eXtended Feature Disable) MSR is context switched with the
        same life time rules as the FPU register state itself. The mechanism
        is keyed off with a static key which is default disabled so !AMX
        equipped CPUs have zero overhead. On AMX enabled CPUs the overhead
        is limited by comparing the tasks XFD value with a per CPU shadow
        variable to avoid redundant MSR writes. In case of switching from a
        AMX using task to a non AMX using task or vice versa, the extra MSR
        write is obviously inevitable.
 
        All other places which need to be aware of the variable feature sets
        and resulting variable sizes are not affected at all because they
        retrieve the information (feature set, sizes) unconditonally from
        the fpstate properties.
 
     6) Enable the new AMX states
 
   Note, this is relatively new code despite the fact that AMX support is in
   the works for more than a year now.
 
   The big refactoring of the FPU code, which allowed to do a proper
   integration has been started exactly 3 weeks ago. Refactoring of the
   existing FPU code and of the original AMX patches took a week and has
   been subject to extensive review and testing. The only fallout which has
   not been caught in review and testing right away was restricted to AMX
   enabled systems, which is completely irrelevant for anyone outside Intel
   and their early access program. There might be dragons lurking as usual,
   but so far the fine grained refactoring has held up and eventual yet
   undetected fallout is bisectable and should be easily addressable before
   the 5.16 release. Famous last words...
 
   Many thanks to Chang Bae and Dave Hansen for working hard on this and
   also to the various test teams at Intel who reserved extra capacity to
   follow the rapid development of this closely which provides the
   confidence level required to offer this rather large update for inclusion
   into 5.16-rc1.
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Merge tag 'x86-fpu-2021-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fpu updates from Thomas Gleixner:

 - Cleanup of extable fixup handling to be more robust, which in turn
   allows to make the FPU exception fixups more robust as well.

 - Change the return code for signal frame related failures from
   explicit error codes to a boolean fail/success as that's all what the
   calling code evaluates.

 - A large refactoring of the FPU code to prepare for adding AMX
   support:

      - Distangle the public header maze and remove especially the
        misnomed kitchen sink internal.h which is despite it's name
        included all over the place.

      - Add a proper abstraction for the register buffer storage (struct
        fpstate) which allows to dynamically size the buffer at runtime
        by flipping the pointer to the buffer container from the default
        container which is embedded in task_struct::tread::fpu to a
        dynamically allocated container with a larger register buffer.

      - Convert the code over to the new fpstate mechanism.

      - Consolidate the KVM FPU handling by moving the FPU related code
        into the FPU core which removes the number of exports and avoids
        adding even more export when AMX has to be supported in KVM.
        This also removes duplicated code which was of course
        unnecessary different and incomplete in the KVM copy.

      - Simplify the KVM FPU buffer handling by utilizing the new
        fpstate container and just switching the buffer pointer from the
        user space buffer to the KVM guest buffer when entering
        vcpu_run() and flipping it back when leaving the function. This
        cuts the memory requirements of a vCPU for FPU buffers in half
        and avoids pointless memory copy operations.

        This also solves the so far unresolved problem of adding AMX
        support because the current FPU buffer handling of KVM inflicted
        a circular dependency between adding AMX support to the core and
        to KVM. With the new scheme of switching fpstate AMX support can
        be added to the core code without affecting KVM.

      - Replace various variables with proper data structures so the
        extra information required for adding dynamically enabled FPU
        features (AMX) can be added in one place

 - Add AMX (Advanced Matrix eXtensions) support (finally):

   AMX is a large XSTATE component which is going to be available with
   Saphire Rapids XEON CPUs. The feature comes with an extra MSR
   (MSR_XFD) which allows to trap the (first) use of an AMX related
   instruction, which has two benefits:

    1) It allows the kernel to control access to the feature

    2) It allows the kernel to dynamically allocate the large register
       state buffer instead of burdening every task with the the extra
       8K or larger state storage.

   It would have been great to gain this kind of control already with
   AVX512.

   The support comes with the following infrastructure components:

    1) arch_prctl() to
        - read the supported features (equivalent to XGETBV(0))
        - read the permitted features for a task
        - request permission for a dynamically enabled feature

       Permission is granted per process, inherited on fork() and
       cleared on exec(). The permission policy of the kernel is
       restricted to sigaltstack size validation, but the syscall
       obviously allows further restrictions via seccomp etc.

    2) A stronger sigaltstack size validation for sys_sigaltstack(2)
       which takes granted permissions and the potentially resulting
       larger signal frame into account. This mechanism can also be used
       to enforce factual sigaltstack validation independent of dynamic
       features to help with finding potential victims of the 2K
       sigaltstack size constant which is broken since AVX512 support
       was added.

    3) Exception handling for #NM traps to catch first use of a extended
       feature via a new cause MSR. If the exception was caused by the
       use of such a feature, the handler checks permission for that
       feature. If permission has not been granted, the handler sends a
       SIGILL like the #UD handler would do if the feature would have
       been disabled in XCR0. If permission has been granted, then a new
       fpstate which fits the larger buffer requirement is allocated.

       In the unlikely case that this allocation fails, the handler
       sends SIGSEGV to the task. That's not elegant, but unavoidable as
       the other discussed options of preallocation or full per task
       permissions come with their own set of horrors for kernel and/or
       userspace. So this is the lesser of the evils and SIGSEGV caused
       by unexpected memory allocation failures is not a fundamentally
       new concept either.

       When allocation succeeds, the fpstate properties are filled in to
       reflect the extended feature set and the resulting sizes, the
       fpu::fpstate pointer is updated accordingly and the trap is
       disarmed for this task permanently.

    4) Enumeration and size calculations

    5) Trap switching via MSR_XFD

       The XFD (eXtended Feature Disable) MSR is context switched with
       the same life time rules as the FPU register state itself. The
       mechanism is keyed off with a static key which is default
       disabled so !AMX equipped CPUs have zero overhead. On AMX enabled
       CPUs the overhead is limited by comparing the tasks XFD value
       with a per CPU shadow variable to avoid redundant MSR writes. In
       case of switching from a AMX using task to a non AMX using task
       or vice versa, the extra MSR write is obviously inevitable.

       All other places which need to be aware of the variable feature
       sets and resulting variable sizes are not affected at all because
       they retrieve the information (feature set, sizes) unconditonally
       from the fpstate properties.

    6) Enable the new AMX states

   Note, this is relatively new code despite the fact that AMX support
   is in the works for more than a year now.

   The big refactoring of the FPU code, which allowed to do a proper
   integration has been started exactly 3 weeks ago. Refactoring of the
   existing FPU code and of the original AMX patches took a week and has
   been subject to extensive review and testing. The only fallout which
   has not been caught in review and testing right away was restricted
   to AMX enabled systems, which is completely irrelevant for anyone
   outside Intel and their early access program. There might be dragons
   lurking as usual, but so far the fine grained refactoring has held up
   and eventual yet undetected fallout is bisectable and should be
   easily addressable before the 5.16 release. Famous last words...

   Many thanks to Chang Bae and Dave Hansen for working hard on this and
   also to the various test teams at Intel who reserved extra capacity
   to follow the rapid development of this closely which provides the
   confidence level required to offer this rather large update for
   inclusion into 5.16-rc1

* tag 'x86-fpu-2021-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (110 commits)
  Documentation/x86: Add documentation for using dynamic XSTATE features
  x86/fpu: Include vmalloc.h for vzalloc()
  selftests/x86/amx: Add context switch test
  selftests/x86/amx: Add test cases for AMX state management
  x86/fpu/amx: Enable the AMX feature in 64-bit mode
  x86/fpu: Add XFD handling for dynamic states
  x86/fpu: Calculate the default sizes independently
  x86/fpu/amx: Define AMX state components and have it used for boot-time checks
  x86/fpu/xstate: Prepare XSAVE feature table for gaps in state component numbers
  x86/fpu/xstate: Add fpstate_realloc()/free()
  x86/fpu/xstate: Add XFD #NM handler
  x86/fpu: Update XFD state where required
  x86/fpu: Add sanity checks for XFD
  x86/fpu: Add XFD state to fpstate
  x86/msr-index: Add MSRs for XFD
  x86/cpufeatures: Add eXtended Feature Disabling (XFD) feature bit
  x86/fpu: Reset permission and fpstate on exec()
  x86/fpu: Prepare fpu_clone() for dynamically enabled features
  x86/fpu/signal: Prepare for variable sigframe length
  x86/signal: Use fpu::__state_user_size for sigalt stack validation
  ...
2021-11-01 14:03:56 -07:00
Peter Zijlstra
87c87ecd00 bpf,x86: Respect X86_FEATURE_RETPOLINE*
Current BPF codegen doesn't respect X86_FEATURE_RETPOLINE* flags and
unconditionally emits a thunk call, this is sub-optimal and doesn't
match the regular, compiler generated, code.

Update the i386 JIT to emit code equal to what the compiler emits for
the regular kernel text (IOW. a plain THUNK call).

Update the x86_64 JIT to emit code similar to the result of compiler
and kernel rewrites as according to X86_FEATURE_RETPOLINE* flags.
Inlining RETPOLINE_AMD (lfence; jmp *%reg) and !RETPOLINE (jmp *%reg),
while doing a THUNK call for RETPOLINE.

This removes the hard-coded retpoline thunks and shrinks the generated
code. Leaving a single retpoline thunk definition in the kernel.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211026120310.614772675@infradead.org
2021-10-28 23:25:29 +02:00
Peter Zijlstra
dceba0817c bpf,x86: Simplify computing label offsets
Take an idea from the 32bit JIT, which uses the multi-pass nature of
the JIT to compute the instruction offsets on a prior pass in order to
compute the relative jump offsets on a later pass.

Application to the x86_64 JIT is slightly more involved because the
offsets depend on program variables (such as callee_regs_used and
stack_depth) and hence the computed offsets need to be kept in the
context of the JIT.

This removes, IMO quite fragile, code that hard-codes the offsets and
tries to compute the length of variable parts of it.

Convert both emit_bpf_tail_call_*() functions which have an out: label
at the end. Additionally emit_bpt_tail_call_direct() also has a poke
table entry, for which it computes the offset from the end (and thus
already relies on the previous pass to have computed addrs[i]), also
convert this to be a forward based offset.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211026120310.552304864@infradead.org
2021-10-28 23:25:29 +02:00
Peter Zijlstra
6fda8a3886 x86/retpoline: Move the retpoline thunk declarations to nospec-branch.h
Because it makes no sense to split the retpoline gunk over multiple
headers.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211026120310.106290934@infradead.org
2021-10-28 23:25:27 +02:00
Ingo Molnar
082f20b21d Merge branch 'x86/urgent' into x86/fpu, to resolve a conflict
Resolve the conflict between these commits:

   x86/fpu:      1193f408cd ("x86/fpu/signal: Change return type of __fpu_restore_sig() to boolean")

   x86/urgent:   d298b03506 ("x86/fpu: Restore the masking out of reserved MXCSR bits")
                 b2381acd3f ("x86/fpu: Mask out the invalid MXCSR bits properly")

 Conflicts:
        arch/x86/kernel/fpu/signal.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-10-16 15:17:46 +02:00
Jie Meng
6364d7d75a bpf, x64: Factor out emission of REX byte in more cases
Introduce a single reg version of maybe_emit_mod() and factor out
common code in more cases.

Signed-off-by: Jie Meng <jmeng@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211006194135.608932-1-jmeng@fb.com
2021-10-07 21:45:06 +02:00
Jie Meng
57a610f1c5 bpf, x64: Save bytes for DIV by reducing reg copies
Instead of unconditionally performing push/pop on %rax/%rdx in case of
division/modulo, we can save a few bytes in case of destination register
being either BPF r0 (%rax) or r3 (%rdx) since the result is written in
there anyway.

Also, we do not need to copy the source to %r11 unless the source is either
%rax, %rdx or an immediate.

For example, before the patch:

  22:   push   %rax
  23:   push   %rdx
  24:   mov    %rsi,%r11
  27:   xor    %edx,%edx
  29:   div    %r11
  2c:   mov    %rax,%r11
  2f:   pop    %rdx
  30:   pop    %rax
  31:   mov    %r11,%rax

After:

  22:   push   %rdx
  23:   xor    %edx,%edx
  25:   div    %rsi
  28:   pop    %rdx

Signed-off-by: Jie Meng <jmeng@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211002035626.2041910-1-jmeng@fb.com
2021-10-06 15:24:36 +02:00
Jakub Kicinski
dd9a887b35 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/phy/bcm7xxx.c
  d88fd1b546 ("net: phy: bcm7xxx: Fixed indirect MMD operations")
  f68d08c437 ("net: phy: bcm7xxx: Add EPHY entry for 72165")

net/sched/sch_api.c
  b193e15ac6 ("net: prevent user from passing illegal stab size")
  69508d4333 ("net_sched: Use struct_size() and flex_array_size() helpers")

Both cases trivial - adjacent code additions.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-09-30 14:49:21 -07:00
Johan Almbladh
ced185824c bpf, x86: Fix bpf mapping of atomic fetch implementation
Fix the case where the dst register maps to %rax as otherwise this produces
an incorrect mapping with the implementation in 981f94c3e9 ("bpf: Add
bitwise atomic instructions") as %rax is clobbered given it's part of the
cmpxchg as operand.

The issue is similar to b29dd96b90 ("bpf, x86: Fix BPF_FETCH atomic and/or/
xor with r0 as src") just that the case of dst register was missed.

Before, dst=r0 (%rax) src=r2 (%rsi):

  [...]
  c5:   mov    %rax,%r10
  c8:   mov    0x0(%rax),%rax       <---+ (broken)
  cc:   mov    %rax,%r11                |
  cf:   and    %rsi,%r11                |
  d2:   lock cmpxchg %r11,0x0(%rax) <---+
  d8:   jne    0x00000000000000c8       |
  da:   mov    %rax,%rsi                |
  dd:   mov    %r10,%rax                |
  [...]                                 |
                                        |
After, dst=r0 (%rax) src=r2 (%rsi):     |
                                        |
  [...]                                 |
  da:	mov    %rax,%r10                |
  dd:	mov    0x0(%r10),%rax       <---+ (fixed)
  e1:	mov    %rax,%r11                |
  e4:	and    %rsi,%r11                |
  e7:	lock cmpxchg %r11,0x0(%r10) <---+
  ed:	jne    0x00000000000000dd
  ef:	mov    %rax,%rsi
  f2:	mov    %r10,%rax
  [...]

The remaining combinations were fine as-is though:

After, dst=r9 (%r15) src=r0 (%rax):

  [...]
  dc:	mov    %rax,%r10
  df:	mov    0x0(%r15),%rax
  e3:	mov    %rax,%r11
  e6:	and    %r10,%r11
  e9:	lock cmpxchg %r11,0x0(%r15)
  ef:	jne    0x00000000000000df      _
  f1:	mov    %rax,%r10                | (unneeded, but
  f4:	mov    %r10,%rax               _|  not a problem)
  [...]

After, dst=r9 (%r15) src=r4 (%rcx):

  [...]
  de:	mov    %rax,%r10
  e1:	mov    0x0(%r15),%rax
  e5:	mov    %rax,%r11
  e8:	and    %rcx,%r11
  eb:	lock cmpxchg %r11,0x0(%r15)
  f1:	jne    0x00000000000000e1
  f3:	mov    %rax,%rcx
  f6:	mov    %r10,%rax
  [...]

The case of dst == src register is rejected by the verifier and
therefore not supported, but x86 JIT also handles this case just
fine.

After, dst=r0 (%rax) src=r0 (%rax):

  [...]
  eb:	mov    %rax,%r10
  ee:	mov    0x0(%r10),%rax
  f2:	mov    %rax,%r11
  f5:	and    %r10,%r11
  f8:	lock cmpxchg %r11,0x0(%r10)
  fe:	jne    0x00000000000000ee
 100:	mov    %rax,%r10
 103:	mov    %r10,%rax
  [...]

Fixes: 981f94c3e9 ("bpf: Add bitwise atomic instructions")
Reported-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Co-developed-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Brendan Jackman <jackmanb@google.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-09-28 12:10:29 +02:00
Jie Meng
c035407743 bpf,x64 Emit IMUL instead of MUL for x86-64
IMUL allows for multiple operands and saving and storing rax/rdx is no
longer needed. Signedness of the operands doesn't matter here because
the we only keep the lower 32/64 bit of the product for 32/64 bit
multiplications.

Signed-off-by: Jie Meng <jmeng@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210913211337.1564014-1-jmeng@fb.com
2021-09-14 18:36:36 -07:00
Hou Tao
356ed64991 bpf: Handle return value of BPF_PROG_TYPE_STRUCT_OPS prog
Currently if a function ptr in struct_ops has a return value, its
caller will get a random return value from it, because the return
value of related BPF_PROG_TYPE_STRUCT_OPS prog is just dropped.

So adding a new flag BPF_TRAMP_F_RET_FENTRY_RET to tell bpf trampoline
to save and return the return value of struct_ops prog if ret_size of
the function ptr is greater than 0. Also restricting the flag to be
used alone.

Fixes: 85d33df357 ("bpf: Introduce BPF_MAP_TYPE_STRUCT_OPS")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210914023351.3664499-1-houtao1@huawei.com
2021-09-14 11:09:50 -07:00
Thomas Gleixner
46d28947d9 x86/extable: Rework the exception table mechanics
The exception table entries contain the instruction address, the fixup
address and the handler address. All addresses are relative. Storing the
handler address has a few downsides:

 1) Most handlers need to be exported

 2) Handlers can be defined everywhere and there is no overview about the
    handler types

 3) MCE needs to check the handler type to decide whether an in kernel #MC
    can be recovered. The functionality of the handler itself is not in any
    way special, but for these checks there need to be separate functions
    which in the worst case have to be exported.

    Some of these 'recoverable' exception fixups are pretty obscure and
    just reuse some other handler to spare code. That obfuscates e.g. the
    #MC safe copy functions. Cleaning that up would require more handlers
    and exports

Rework the exception fixup mechanics by storing a fixup type number instead
of the handler address and invoke the proper handler for each fixup
type. Also teach the extable sort to leave the type field alone.

This makes most handlers static except for special cases like the MCE
MSR fixup and the BPF fixup. This allows to add more types for cleaning up
the obscure places without adding more handler code and exports.

There is a marginal code size reduction for a production config and it
removes _eight_ exported symbols.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lkml.kernel.org/r/20210908132525.211958725@linutronix.de
2021-09-13 17:51:47 +02:00
Jakub Kicinski
d2e11fd2b7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicting commits, all resolutions pretty trivial:

drivers/bus/mhi/pci_generic.c
  5c2c853159 ("bus: mhi: pci-generic: configurable network interface MRU")
  56f6f4c4eb ("bus: mhi: pci_generic: Apply no-op for wake using sideband wake boolean")

drivers/nfc/s3fwrn5/firmware.c
  a0302ff590 ("nfc: s3fwrn5: remove unnecessary label")
  46573e3ab0 ("nfc: s3fwrn5: fix undefined parameter values in dev_err()")
  801e541c79 ("nfc: s3fwrn5: fix undefined parameter values in dev_err()")

MAINTAINERS
  7d901a1e87 ("net: phy: add Maxlinear GPY115/21x/24x driver")
  8a7b46fa79 ("MAINTAINERS: add Yasushi SHOJI as reviewer for the Microchip CAN BUS Analyzer Tool driver")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-07-31 09:14:46 -07:00
Daniel Borkmann
f5e81d1117 bpf: Introduce BPF nospec instruction for mitigating Spectre v4
In case of JITs, each of the JIT backends compiles the BPF nospec instruction
/either/ to a machine instruction which emits a speculation barrier /or/ to
/no/ machine instruction in case the underlying architecture is not affected
by Speculative Store Bypass or has different mitigations in place already.

This covers both x86 and (implicitly) arm64: In case of x86, we use 'lfence'
instruction for mitigation. In case of arm64, we rely on the firmware mitigation
as controlled via the ssbd kernel parameter. Whenever the mitigation is enabled,
it works for all of the kernel code with no need to provide any additional
instructions here (hence only comment in arm64 JIT). Other archs can follow
as needed. The BPF nospec instruction is specifically targeting Spectre v4
since i) we don't use a serialization barrier for the Spectre v1 case, and
ii) mitigation instructions for v1 and v4 might be different on some archs.

The BPF nospec is required for a future commit, where the BPF verifier does
annotate intermediate BPF programs with speculation barriers.

Co-developed-by: Piotr Krysiuk <piotras@gmail.com>
Co-developed-by: Benedict Schlueter <benedict.schlueter@rub.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Signed-off-by: Benedict Schlueter <benedict.schlueter@rub.de>
Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-07-29 00:20:56 +02:00
David S. Miller
82a1ffe57e Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-07-15

The following pull-request contains BPF updates for your *net-next* tree.

We've added 45 non-merge commits during the last 15 day(s) which contain
a total of 52 files changed, 3122 insertions(+), 384 deletions(-).

The main changes are:

1) Introduce bpf timers, from Alexei.

2) Add sockmap support for unix datagram socket, from Cong.

3) Fix potential memleak and UAF in the verifier, from He.

4) Add bpf_get_func_ip helper, from Jiri.

5) Improvements to generic XDP mode, from Kumar.

6) Support for passing xdp_md to XDP programs in bpf_prog_run, from Zvi.
===================

Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-15 22:40:10 -07:00
Jiri Olsa
7e6f3cd89f bpf, x86: Store caller's ip in trampoline stack
Storing caller's ip in trampoline's stack. Trampoline programs
can reach the IP in (ctx - 8) address, so there's no change in
program's arguments interface.

The IP address is takes from [fp + 8], which is return address
from the initial 'call fentry' call to trampoline.

This IP address will be returned via bpf_get_func_ip helper
helper, which is added in following patches.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210714094400.396467-2-jolsa@kernel.org
2021-07-15 17:16:06 -07:00
John Fastabend
f263a81451 bpf: Track subprog poke descriptors correctly and fix use-after-free
Subprograms are calling map_poke_track(), but on program release there is no
hook to call map_poke_untrack(). However, on program release, the aux memory
(and poke descriptor table) is freed even though we still have a reference to
it in the element list of the map aux data. When we run map_poke_run(), we then
end up accessing free'd memory, triggering KASAN in prog_array_map_poke_run():

  [...]
  [  402.824689] BUG: KASAN: use-after-free in prog_array_map_poke_run+0xc2/0x34e
  [  402.824698] Read of size 4 at addr ffff8881905a7940 by task hubble-fgs/4337
  [  402.824705] CPU: 1 PID: 4337 Comm: hubble-fgs Tainted: G          I       5.12.0+ #399
  [  402.824715] Call Trace:
  [  402.824719]  dump_stack+0x93/0xc2
  [  402.824727]  print_address_description.constprop.0+0x1a/0x140
  [  402.824736]  ? prog_array_map_poke_run+0xc2/0x34e
  [  402.824740]  ? prog_array_map_poke_run+0xc2/0x34e
  [  402.824744]  kasan_report.cold+0x7c/0xd8
  [  402.824752]  ? prog_array_map_poke_run+0xc2/0x34e
  [  402.824757]  prog_array_map_poke_run+0xc2/0x34e
  [  402.824765]  bpf_fd_array_map_update_elem+0x124/0x1a0
  [...]

The elements concerned are walked as follows:

    for (i = 0; i < elem->aux->size_poke_tab; i++) {
           poke = &elem->aux->poke_tab[i];
    [...]

The access to size_poke_tab is a 4 byte read, verified by checking offsets
in the KASAN dump:

  [  402.825004] The buggy address belongs to the object at ffff8881905a7800
                 which belongs to the cache kmalloc-1k of size 1024
  [  402.825008] The buggy address is located 320 bytes inside of
                 1024-byte region [ffff8881905a7800, ffff8881905a7c00)

The pahole output of bpf_prog_aux:

  struct bpf_prog_aux {
    [...]
    /* --- cacheline 5 boundary (320 bytes) --- */
    u32                        size_poke_tab;        /*   320     4 */
    [...]

In general, subprograms do not necessarily manage their own data structures.
For example, BTF func_info and linfo are just pointers to the main program
structure. This allows reference counting and cleanup to be done on the latter
which simplifies their management a bit. The aux->poke_tab struct, however,
did not follow this logic. The initial proposed fix for this use-after-free
bug further embedded poke data tracking into the subprogram with proper
reference counting. However, Daniel and Alexei questioned why we were treating
these objects special; I agree, its unnecessary. The fix here removes the per
subprogram poke table allocation and map tracking and instead simply points
the aux->poke_tab pointer at the main programs poke table. This way, map
tracking is simplified to the main program and we do not need to manage them
per subprogram.

This also means, bpf_prog_free_deferred(), which unwinds the program reference
counting and kfrees objects, needs to ensure that we don't try to double free
the poke_tab when free'ing the subprog structures. This is easily solved by
NULL'ing the poke_tab pointer. The second detail is to ensure that per
subprogram JIT logic only does fixups on poke_tab[] entries it owns. To do
this, we add a pointer in the poke structure to point at the subprogram value
so JITs can easily check while walking the poke_tab structure if the current
entry belongs to the current program. The aux pointer is stable and therefore
suitable for such comparison. On the jit_subprogs() error path, we omit
cleaning up the poke->aux field because these are only ever referenced from
the JIT side, but on error we will never make it to the JIT, so its fine to
leave them dangling. Removing these pointers would complicate the error path
for no reason. However, we do need to untrack all poke descriptors from the
main program as otherwise they could race with the freeing of JIT memory from
the subprograms. Lastly, a748c6975d ("bpf: propagate poke descriptors to
subprograms") had an off-by-one on the subprogram instruction index range
check as it was testing 'insn_idx >= subprog_start && insn_idx <= subprog_end'.
However, subprog_end is the next subprogram's start instruction.

Fixes: a748c6975d ("bpf: propagate poke descriptors to subprograms")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Co-developed-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210707223848.14580-2-john.fastabend@gmail.com
2021-07-09 12:08:27 +02:00
Ravi Bangoria
328aac5ecd bpf, x86: Fix extable offset calculation
Commit 4c5de12759 ("bpf: Emit explicit NULL pointer checks for PROBE_LDX
instructions.") is emitting a couple of instructions before the actual load.
Consider those additional instructions while calculating extable offset.

Fixes: 4c5de12759 ("bpf: Emit explicit NULL pointer checks for PROBE_LDX instructions.")
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210622110026.1157847-1-ravi.bangoria@linux.ibm.com
2021-06-28 15:11:43 +02:00
Jiri Olsa
ced50fc49f bpf, x86: Remove unused cnt increase from EMIT macro
Removing unused cnt increase from EMIT macro together with cnt declarations.
This was introduced in commit [1] to ensure proper code generation. But that
code was removed in commit [2] and this extra code was left in.

  [1] b52f00e6a7 ("x86: bpf_jit: implement bpf_tail_call() helper")
  [2] ebf7d1f508 ("bpf, x64: rework pro/epilogue and tailcall handling in JIT")

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210623112504.709856-1-jolsa@kernel.org
2021-06-24 13:39:56 +02:00
Linus Torvalds
9d31d23389 Networking changes for 5.13.
Core:
 
  - bpf:
 	- allow bpf programs calling kernel functions (initially to
 	  reuse TCP congestion control implementations)
 	- enable task local storage for tracing programs - remove the
 	  need to store per-task state in hash maps, and allow tracing
 	  programs access to task local storage previously added for
 	  BPF_LSM
 	- add bpf_for_each_map_elem() helper, allowing programs to
 	  walk all map elements in a more robust and easier to verify
 	  fashion
 	- sockmap: support UDP and cross-protocol BPF_SK_SKB_VERDICT
 	  redirection
 	- lpm: add support for batched ops in LPM trie
 	- add BTF_KIND_FLOAT support - mostly to allow use of BTF
 	  on s390 which has floats in its headers files
 	- improve BPF syscall documentation and extend the use of kdoc
 	  parsing scripts we already employ for bpf-helpers
 	- libbpf, bpftool: support static linking of BPF ELF files
 	- improve support for encapsulation of L2 packets
 
  - xdp: restructure redirect actions to avoid a runtime lookup,
 	improving performance by 4-8% in microbenchmarks
 
  - xsk: build skb by page (aka generic zerocopy xmit) - improve
 	performance of software AF_XDP path by 33% for devices
 	which don't need headers in the linear skb part (e.g. virtio)
 
  - nexthop: resilient next-hop groups - improve path stability
 	on next-hops group changes (incl. offload for mlxsw)
 
  - ipv6: segment routing: add support for IPv4 decapsulation
 
  - icmp: add support for RFC 8335 extended PROBE messages
 
  - inet: use bigger hash table for IP ID generation
 
  - tcp: deal better with delayed TX completions - make sure we don't
 	give up on fast TCP retransmissions only because driver is
 	slow in reporting that it completed transmitting the original
 
  - tcp: reorder tcp_congestion_ops for better cache locality
 
  - mptcp:
 	- add sockopt support for common TCP options
 	- add support for common TCP msg flags
 	- include multiple address ids in RM_ADDR
 	- add reset option support for resetting one subflow
 
  - udp: GRO L4 improvements - improve 'forward' / 'frag_list'
 	co-existence with UDP tunnel GRO, allowing the first to take
 	place correctly	even for encapsulated UDP traffic
 
  - micro-optimize dev_gro_receive() and flow dissection, avoid
 	retpoline overhead on VLAN and TEB GRO
 
  - use less memory for sysctls, add a new sysctl type, to allow using
 	u8 instead of "int" and "long" and shrink networking sysctls
 
  - veth: allow GRO without XDP - this allows aggregating UDP
 	packets before handing them off to routing, bridge, OvS, etc.
 
  - allow specifing ifindex when device is moved to another namespace
 
  - netfilter:
 	- nft_socket: add support for cgroupsv2
 	- nftables: add catch-all set element - special element used
 	  to define a default action in case normal lookup missed
 	- use net_generic infra in many modules to avoid allocating
 	  per-ns memory unnecessarily
 
  - xps: improve the xps handling to avoid potential out-of-bound
 	accesses and use-after-free when XPS change race with other
 	re-configuration under traffic
 
  - add a config knob to turn off per-cpu netdev refcnt to catch
 	underflows in testing
 
 Device APIs:
 
  - add WWAN subsystem to organize the WWAN interfaces better and
    hopefully start driving towards more unified and vendor-
    -independent APIs
 
  - ethtool:
 	- add interface for reading IEEE MIB stats (incl. mlx5 and
 	  bnxt support)
 	- allow network drivers to dump arbitrary SFP EEPROM data,
 	  current offset+length API was a poor fit for modern SFP
 	  which define EEPROM in terms of pages (incl. mlx5 support)
 
  - act_police, flow_offload: add support for packet-per-second
 	policing (incl. offload for nfp)
 
  - psample: add additional metadata attributes like transit delay
 	for packets sampled from switch HW (and corresponding egress
 	and policy-based sampling in the mlxsw driver)
 
  - dsa: improve support for sandwiched LAGs with bridge and DSA
 
  - netfilter:
 	- flowtable: use direct xmit in topologies with IP
 	  forwarding, bridging, vlans etc.
 	- nftables: counter hardware offload support
 
  - Bluetooth:
 	- improvements for firmware download w/ Intel devices
 	- add support for reading AOSP vendor capabilities
 	- add support for virtio transport driver
 
  - mac80211:
 	- allow concurrent monitor iface and ethernet rx decap
 	- set priority and queue mapping for injected frames
 
  - phy: add support for Clause-45 PHY Loopback
 
  - pci/iov: add sysfs MSI-X vector assignment interface
 	to distribute MSI-X resources to VFs (incl. mlx5 support)
 
 New hardware/drivers:
 
  - dsa: mv88e6xxx: add support for Marvell mv88e6393x -
 	11-port Ethernet switch with 8x 1-Gigabit Ethernet
 	and 3x 10-Gigabit interfaces.
 
  - dsa: support for legacy Broadcom tags used on BCM5325, BCM5365
 	and BCM63xx switches
 
  - Microchip KSZ8863 and KSZ8873; 3x 10/100Mbps Ethernet switches
 
  - ath11k: support for QCN9074 a 802.11ax device
 
  - Bluetooth: Broadcom BCM4330 and BMC4334
 
  - phy: Marvell 88X2222 transceiver support
 
  - mdio: add BCM6368 MDIO mux bus controller
 
  - r8152: support RTL8153 and RTL8156 (USB Ethernet) chips
 
  - mana: driver for Microsoft Azure Network Adapter (MANA)
 
  - Actions Semi Owl Ethernet MAC
 
  - can: driver for ETAS ES58X CAN/USB interfaces
 
 Pure driver changes:
 
  - add XDP support to: enetc, igc, stmmac
  - add AF_XDP support to: stmmac
 
  - virtio:
 	- page_to_skb() use build_skb when there's sufficient tailroom
 	  (21% improvement for 1000B UDP frames)
 	- support XDP even without dedicated Tx queues - share the Tx
 	  queues with the stack when necessary
 
  - mlx5:
 	- flow rules: add support for mirroring with conntrack,
 	  matching on ICMP, GTP, flex filters and more
 	- support packet sampling with flow offloads
 	- persist uplink representor netdev across eswitch mode
 	  changes
 	- allow coexistence of CQE compression and HW time-stamping
 	- add ethtool extended link error state reporting
 
  - ice, iavf: support flow filters, UDP Segmentation Offload
 
  - dpaa2-switch:
 	- move the driver out of staging
 	- add spanning tree (STP) support
 	- add rx copybreak support
 	- add tc flower hardware offload on ingress traffic
 
  - ionic:
 	- implement Rx page reuse
 	- support HW PTP time-stamping
 
  - octeon: support TC hardware offloads - flower matching on ingress
 	and egress ratelimitting.
 
  - stmmac:
 	- add RX frame steering based on VLAN priority in tc flower
 	- support frame preemption (FPE)
 	- intel: add cross time-stamping freq difference adjustment
 
  - ocelot:
 	- support forwarding of MRP frames in HW
 	- support multiple bridges
 	- support PTP Sync one-step timestamping
 
  - dsa: mv88e6xxx, dpaa2-switch: offload bridge port flags like
 	learning, flooding etc.
 
  - ipa: add IPA v4.5, v4.9 and v4.11 support (Qualcomm SDX55, SM8350,
 	SC7280 SoCs)
 
  - mt7601u: enable TDLS support
 
  - mt76:
 	- add support for 802.3 rx frames (mt7915/mt7615)
 	- mt7915 flash pre-calibration support
 	- mt7921/mt7663 runtime power management fixes
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core:

   - bpf:
        - allow bpf programs calling kernel functions (initially to
          reuse TCP congestion control implementations)
        - enable task local storage for tracing programs - remove the
          need to store per-task state in hash maps, and allow tracing
          programs access to task local storage previously added for
          BPF_LSM
        - add bpf_for_each_map_elem() helper, allowing programs to walk
          all map elements in a more robust and easier to verify fashion
        - sockmap: support UDP and cross-protocol BPF_SK_SKB_VERDICT
          redirection
        - lpm: add support for batched ops in LPM trie
        - add BTF_KIND_FLOAT support - mostly to allow use of BTF on
          s390 which has floats in its headers files
        - improve BPF syscall documentation and extend the use of kdoc
          parsing scripts we already employ for bpf-helpers
        - libbpf, bpftool: support static linking of BPF ELF files
        - improve support for encapsulation of L2 packets

   - xdp: restructure redirect actions to avoid a runtime lookup,
     improving performance by 4-8% in microbenchmarks

   - xsk: build skb by page (aka generic zerocopy xmit) - improve
     performance of software AF_XDP path by 33% for devices which don't
     need headers in the linear skb part (e.g. virtio)

   - nexthop: resilient next-hop groups - improve path stability on
     next-hops group changes (incl. offload for mlxsw)

   - ipv6: segment routing: add support for IPv4 decapsulation

   - icmp: add support for RFC 8335 extended PROBE messages

   - inet: use bigger hash table for IP ID generation

   - tcp: deal better with delayed TX completions - make sure we don't
     give up on fast TCP retransmissions only because driver is slow in
     reporting that it completed transmitting the original

   - tcp: reorder tcp_congestion_ops for better cache locality

   - mptcp:
        - add sockopt support for common TCP options
        - add support for common TCP msg flags
        - include multiple address ids in RM_ADDR
        - add reset option support for resetting one subflow

   - udp: GRO L4 improvements - improve 'forward' / 'frag_list'
     co-existence with UDP tunnel GRO, allowing the first to take place
     correctly even for encapsulated UDP traffic

   - micro-optimize dev_gro_receive() and flow dissection, avoid
     retpoline overhead on VLAN and TEB GRO

   - use less memory for sysctls, add a new sysctl type, to allow using
     u8 instead of "int" and "long" and shrink networking sysctls

   - veth: allow GRO without XDP - this allows aggregating UDP packets
     before handing them off to routing, bridge, OvS, etc.

   - allow specifing ifindex when device is moved to another namespace

   - netfilter:
        - nft_socket: add support for cgroupsv2
        - nftables: add catch-all set element - special element used to
          define a default action in case normal lookup missed
        - use net_generic infra in many modules to avoid allocating
          per-ns memory unnecessarily

   - xps: improve the xps handling to avoid potential out-of-bound
     accesses and use-after-free when XPS change race with other
     re-configuration under traffic

   - add a config knob to turn off per-cpu netdev refcnt to catch
     underflows in testing

  Device APIs:

   - add WWAN subsystem to organize the WWAN interfaces better and
     hopefully start driving towards more unified and vendor-
     independent APIs

   - ethtool:
        - add interface for reading IEEE MIB stats (incl. mlx5 and bnxt
          support)
        - allow network drivers to dump arbitrary SFP EEPROM data,
          current offset+length API was a poor fit for modern SFP which
          define EEPROM in terms of pages (incl. mlx5 support)

   - act_police, flow_offload: add support for packet-per-second
     policing (incl. offload for nfp)

   - psample: add additional metadata attributes like transit delay for
     packets sampled from switch HW (and corresponding egress and
     policy-based sampling in the mlxsw driver)

   - dsa: improve support for sandwiched LAGs with bridge and DSA

   - netfilter:
        - flowtable: use direct xmit in topologies with IP forwarding,
          bridging, vlans etc.
        - nftables: counter hardware offload support

   - Bluetooth:
        - improvements for firmware download w/ Intel devices
        - add support for reading AOSP vendor capabilities
        - add support for virtio transport driver

   - mac80211:
        - allow concurrent monitor iface and ethernet rx decap
        - set priority and queue mapping for injected frames

   - phy: add support for Clause-45 PHY Loopback

   - pci/iov: add sysfs MSI-X vector assignment interface to distribute
     MSI-X resources to VFs (incl. mlx5 support)

  New hardware/drivers:

   - dsa: mv88e6xxx: add support for Marvell mv88e6393x - 11-port
     Ethernet switch with 8x 1-Gigabit Ethernet and 3x 10-Gigabit
     interfaces.

   - dsa: support for legacy Broadcom tags used on BCM5325, BCM5365 and
     BCM63xx switches

   - Microchip KSZ8863 and KSZ8873; 3x 10/100Mbps Ethernet switches

   - ath11k: support for QCN9074 a 802.11ax device

   - Bluetooth: Broadcom BCM4330 and BMC4334

   - phy: Marvell 88X2222 transceiver support

   - mdio: add BCM6368 MDIO mux bus controller

   - r8152: support RTL8153 and RTL8156 (USB Ethernet) chips

   - mana: driver for Microsoft Azure Network Adapter (MANA)

   - Actions Semi Owl Ethernet MAC

   - can: driver for ETAS ES58X CAN/USB interfaces

  Pure driver changes:

   - add XDP support to: enetc, igc, stmmac

   - add AF_XDP support to: stmmac

   - virtio:
        - page_to_skb() use build_skb when there's sufficient tailroom
          (21% improvement for 1000B UDP frames)
        - support XDP even without dedicated Tx queues - share the Tx
          queues with the stack when necessary

   - mlx5:
        - flow rules: add support for mirroring with conntrack, matching
          on ICMP, GTP, flex filters and more
        - support packet sampling with flow offloads
        - persist uplink representor netdev across eswitch mode changes
        - allow coexistence of CQE compression and HW time-stamping
        - add ethtool extended link error state reporting

   - ice, iavf: support flow filters, UDP Segmentation Offload

   - dpaa2-switch:
        - move the driver out of staging
        - add spanning tree (STP) support
        - add rx copybreak support
        - add tc flower hardware offload on ingress traffic

   - ionic:
        - implement Rx page reuse
        - support HW PTP time-stamping

   - octeon: support TC hardware offloads - flower matching on ingress
     and egress ratelimitting.

   - stmmac:
        - add RX frame steering based on VLAN priority in tc flower
        - support frame preemption (FPE)
        - intel: add cross time-stamping freq difference adjustment

   - ocelot:
        - support forwarding of MRP frames in HW
        - support multiple bridges
        - support PTP Sync one-step timestamping

   - dsa: mv88e6xxx, dpaa2-switch: offload bridge port flags like
     learning, flooding etc.

   - ipa: add IPA v4.5, v4.9 and v4.11 support (Qualcomm SDX55, SM8350,
     SC7280 SoCs)

   - mt7601u: enable TDLS support

   - mt76:
        - add support for 802.3 rx frames (mt7915/mt7615)
        - mt7915 flash pre-calibration support
        - mt7921/mt7663 runtime power management fixes"

* tag 'net-next-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2451 commits)
  net: selftest: fix build issue if INET is disabled
  net: netrom: nr_in: Remove redundant assignment to ns
  net: tun: Remove redundant assignment to ret
  net: phy: marvell: add downshift support for M88E1240
  net: dsa: ksz: Make reg_mib_cnt a u8 as it never exceeds 255
  net/sched: act_ct: Remove redundant ct get and check
  icmp: standardize naming of RFC 8335 PROBE constants
  bpf, selftests: Update array map tests for per-cpu batched ops
  bpf: Add batched ops support for percpu array
  bpf: Implement formatted output helpers with bstr_printf
  seq_file: Add a seq_bprintf function
  sfc: adjust efx->xdp_tx_queue_count with the real number of initialized queues
  net:nfc:digital: Fix a double free in digital_tg_recv_dep_req
  net: fix a concurrency bug in l2tp_tunnel_register()
  net/smc: Remove redundant assignment to rc
  mpls: Remove redundant assignment to err
  llc2: Remove redundant assignment to rc
  net/tls: Remove redundant initialization of record
  rds: Remove redundant assignment to nr_sig
  dt-bindings: net: mdio-gpio: add compatible for microchip,mdio-smi0
  ...
2021-04-29 11:57:23 -07:00
Linus Torvalds
c6536676c7 - turn the stack canary into a normal __percpu variable on 32-bit which
gets rid of the LAZY_GS stuff and a lot of code.
 
 - Add an insn_decode() API which all users of the instruction decoder
 should preferrably use. Its goal is to keep the details of the
 instruction decoder away from its users and simplify and streamline how
 one decodes insns in the kernel. Convert its users to it.
 
 - kprobes improvements and fixes
 
 - Set the maximum DIE per package variable on Hygon
 
 - Rip out the dynamic NOP selection and simplify all the machinery around
 selecting NOPs. Use the simplified NOPs in objtool now too.
 
 - Add Xeon Sapphire Rapids to list of CPUs that support PPIN
 
 - Simplify the retpolines by folding the entire thing into an
 alternative now that objtool can handle alternatives with stack
 ops. Then, have objtool rewrite the call to the retpoline with the
 alternative which then will get patched at boot time.
 
 - Document Intel uarch per models in intel-family.h
 
 - Make Sub-NUMA Clustering topology the default and Cluster-on-Die the
 exception on Intel.
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Merge tag 'x86_core_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 updates from Borislav Petkov:

 - Turn the stack canary into a normal __percpu variable on 32-bit which
   gets rid of the LAZY_GS stuff and a lot of code.

 - Add an insn_decode() API which all users of the instruction decoder
   should preferrably use. Its goal is to keep the details of the
   instruction decoder away from its users and simplify and streamline
   how one decodes insns in the kernel. Convert its users to it.

 - kprobes improvements and fixes

 - Set the maximum DIE per package variable on Hygon

 - Rip out the dynamic NOP selection and simplify all the machinery
   around selecting NOPs. Use the simplified NOPs in objtool now too.

 - Add Xeon Sapphire Rapids to list of CPUs that support PPIN

 - Simplify the retpolines by folding the entire thing into an
   alternative now that objtool can handle alternatives with stack ops.
   Then, have objtool rewrite the call to the retpoline with the
   alternative which then will get patched at boot time.

 - Document Intel uarch per models in intel-family.h

 - Make Sub-NUMA Clustering topology the default and Cluster-on-Die the
   exception on Intel.

* tag 'x86_core_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  x86, sched: Treat Intel SNC topology as default, COD as exception
  x86/cpu: Comment Skylake server stepping too
  x86/cpu: Resort and comment Intel models
  objtool/x86: Rewrite retpoline thunk calls
  objtool: Skip magical retpoline .altinstr_replacement
  objtool: Cache instruction relocs
  objtool: Keep track of retpoline call sites
  objtool: Add elf_create_undef_symbol()
  objtool: Extract elf_symbol_add()
  objtool: Extract elf_strtab_concat()
  objtool: Create reloc sections implicitly
  objtool: Add elf_create_reloc() helper
  objtool: Rework the elf_rebuild_reloc_section() logic
  objtool: Fix static_call list generation
  objtool: Handle per arch retpoline naming
  objtool: Correctly handle retpoline thunk calls
  x86/retpoline: Simplify retpolines
  x86/alternatives: Optimize optimize_nops()
  x86: Add insn_decode_kernel()
  x86/kprobes: Move 'inline' to the beginning of the kprobe_is_ss() declaration
  ...
2021-04-27 17:45:09 -07:00
Linus Torvalds
ea5bc7b977 Trivial cleanups and fixes all over the place.
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Merge tag 'x86_cleanups_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull misc x86 cleanups from Borislav Petkov:
 "Trivial cleanups and fixes all over the place"

* tag 'x86_cleanups_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  MAINTAINERS: Remove me from IDE/ATAPI section
  x86/pat: Do not compile stubbed functions when X86_PAT is off
  x86/asm: Ensure asm/proto.h can be included stand-alone
  x86/platform/intel/quark: Fix incorrect kernel-doc comment syntax in files
  x86/msr: Make locally used functions static
  x86/cacheinfo: Remove unneeded dead-store initialization
  x86/process/64: Move cpu_current_top_of_stack out of TSS
  tools/turbostat: Unmark non-kernel-doc comment
  x86/syscalls: Fix -Wmissing-prototypes warnings from COND_SYSCALL()
  x86/fpu/math-emu: Fix function cast warning
  x86/msr: Fix wr/rdmsr_safe_regs_on_cpu() prototypes
  x86: Fix various typos in comments, take #2
  x86: Remove unusual Unicode characters from comments
  x86/kaslr: Return boolean values from a function returning bool
  x86: Fix various typos in comments
  x86/setup: Remove unused RESERVE_BRK_ARRAY()
  stacktrace: Move documentation for arch_stack_walk_reliable() to header
  x86: Remove duplicate TSC DEADLINE MSR definitions
2021-04-26 09:25:47 -07:00
Jakub Kicinski
8859a44ea0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts:

MAINTAINERS
 - keep Chandrasekar
drivers/net/ethernet/mellanox/mlx5/core/en_main.c
 - simple fix + trust the code re-added to param.c in -next is fine
include/linux/bpf.h
 - trivial
include/linux/ethtool.h
 - trivial, fix kdoc while at it
include/linux/skmsg.h
 - move to relevant place in tcp.c, comment re-wrapped
net/core/skmsg.c
 - add the sk = sk // sk = NULL around calls
net/tipc/crypto.c
 - trivial

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-04-09 20:48:35 -07:00
Piotr Krysiuk
26f55a59dc bpf, x86: Validate computation of branch displacements for x86-32
The branch displacement logic in the BPF JIT compilers for x86 assumes
that, for any generated branch instruction, the distance cannot
increase between optimization passes.

But this assumption can be violated due to how the distances are
computed. Specifically, whenever a backward branch is processed in
do_jit(), the distance is computed by subtracting the positions in the
machine code from different optimization passes. This is because part
of addrs[] is already updated for the current optimization pass, before
the branch instruction is visited.

And so the optimizer can expand blocks of machine code in some cases.

This can confuse the optimizer logic, where it assumes that a fixed
point has been reached for all machine code blocks once the total
program size stops changing. And then the JIT compiler can output
abnormal machine code containing incorrect branch displacements.

To mitigate this issue, we assert that a fixed point is reached while
populating the output image. This rejects any problematic programs.
The issue affects both x86-32 and x86-64. We mitigate separately to
ease backporting.

Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Reviewed-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2021-04-08 16:24:53 +02:00
Piotr Krysiuk
e4d4d45643 bpf, x86: Validate computation of branch displacements for x86-64
The branch displacement logic in the BPF JIT compilers for x86 assumes
that, for any generated branch instruction, the distance cannot
increase between optimization passes.

But this assumption can be violated due to how the distances are
computed. Specifically, whenever a backward branch is processed in
do_jit(), the distance is computed by subtracting the positions in the
machine code from different optimization passes. This is because part
of addrs[] is already updated for the current optimization pass, before
the branch instruction is visited.

And so the optimizer can expand blocks of machine code in some cases.

This can confuse the optimizer logic, where it assumes that a fixed
point has been reached for all machine code blocks once the total
program size stops changing. And then the JIT compiler can output
abnormal machine code containing incorrect branch displacements.

To mitigate this issue, we assert that a fixed point is reached while
populating the output image. This rejects any problematic programs.
The issue affects both x86-32 and x86-64. We mitigate separately to
ease backporting.

Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Reviewed-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2021-04-08 16:24:36 +02:00
Ingo Molnar
b1f480bc06 Merge branch 'x86/cpu' into WIP.x86/core, to merge the NOP changes & resolve a semantic conflict
Conflict-merge this main commit in essence:

  a89dfde3dc: ("x86: Remove dynamic NOP selection")

With this upstream commit:

  b908297047: ("bpf: Use NOP_ATOMIC5 instead of emit_nops(&prog, 5) for BPF_TRAMP_F_CALL_ORIG")

Semantic merge conflict:

  arch/x86/net/bpf_jit_comp.c

  - memcpy(prog, ideal_nops[NOP_ATOMIC5], X86_PATCH_SIZE);
  + memcpy(prog, x86_nops[5], X86_PATCH_SIZE);

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-04-02 12:36:30 +02:00
Martin KaFai Lau
797b84f727 bpf: Support kernel function call in x86-32
This patch adds kernel function call support to the x86-32 bpf jit.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210325015149.1545267-1-kafai@fb.com
2021-03-26 20:41:51 -07:00
Martin KaFai Lau
e6ac2450d6 bpf: Support bpf program calling kernel function
This patch adds support to BPF verifier to allow bpf program calling
kernel function directly.

The use case included in this set is to allow bpf-tcp-cc to directly
call some tcp-cc helper functions (e.g. "tcp_cong_avoid_ai()").  Those
functions have already been used by some kernel tcp-cc implementations.

This set will also allow the bpf-tcp-cc program to directly call the
kernel tcp-cc implementation,  For example, a bpf_dctcp may only want to
implement its own dctcp_cwnd_event() and reuse other dctcp_*() directly
from the kernel tcp_dctcp.c instead of reimplementing (or
copy-and-pasting) them.

The tcp-cc kernel functions mentioned above will be white listed
for the struct_ops bpf-tcp-cc programs to use in a later patch.
The white listed functions are not bounded to a fixed ABI contract.
Those functions have already been used by the existing kernel tcp-cc.
If any of them has changed, both in-tree and out-of-tree kernel tcp-cc
implementations have to be changed.  The same goes for the struct_ops
bpf-tcp-cc programs which have to be adjusted accordingly.

This patch is to make the required changes in the bpf verifier.

First change is in btf.c, it adds a case in "btf_check_func_arg_match()".
When the passed in "btf->kernel_btf == true", it means matching the
verifier regs' states with a kernel function.  This will handle the
PTR_TO_BTF_ID reg.  It also maps PTR_TO_SOCK_COMMON, PTR_TO_SOCKET,
and PTR_TO_TCP_SOCK to its kernel's btf_id.

In the later libbpf patch, the insn calling a kernel function will
look like:

insn->code == (BPF_JMP | BPF_CALL)
insn->src_reg == BPF_PSEUDO_KFUNC_CALL /* <- new in this patch */
insn->imm == func_btf_id /* btf_id of the running kernel */

[ For the future calling function-in-kernel-module support, an array
  of module btf_fds can be passed at the load time and insn->off
  can be used to index into this array. ]

At the early stage of verifier, the verifier will collect all kernel
function calls into "struct bpf_kfunc_desc".  Those
descriptors are stored in "prog->aux->kfunc_tab" and will
be available to the JIT.  Since this "add" operation is similar
to the current "add_subprog()" and looking for the same insn->code,
they are done together in the new "add_subprog_and_kfunc()".

In the "do_check()" stage, the new "check_kfunc_call()" is added
to verify the kernel function call instruction:
1. Ensure the kernel function can be used by a particular BPF_PROG_TYPE.
   A new bpf_verifier_ops "check_kfunc_call" is added to do that.
   The bpf-tcp-cc struct_ops program will implement this function in
   a later patch.
2. Call "btf_check_kfunc_args_match()" to ensure the regs can be
   used as the args of a kernel function.
3. Mark the regs' type, subreg_def, and zext_dst.

At the later do_misc_fixups() stage, the new fixup_kfunc_call()
will replace the insn->imm with the function address (relative
to __bpf_call_base).  If needed, the jit can find the btf_func_model
by calling the new bpf_jit_find_kfunc_model(prog, insn).
With the imm set to the function address, "bpftool prog dump xlated"
will be able to display the kernel function calls the same way as
it displays other bpf helper calls.

gpl_compatible program is required to call kernel function.

This feature currently requires JIT.

The verifier selftests are adjusted because of the changes in
the verbose log in add_subprog_and_kfunc().

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210325015142.1544736-1-kafai@fb.com
2021-03-26 20:41:51 -07:00