Commit Graph

273 Commits

Author SHA1 Message Date
Rafael Passos
9919c5c98c bpf: remove unused parameter in bpf_jit_binary_pack_finalize
Fixes a compiler warning. the bpf_jit_binary_pack_finalize function
was taking an extra bpf_prog parameter that went unused.
This removves it and updates the callers accordingly.

Signed-off-by: Rafael Passos <rafael@rcpassos.me>
Link: https://lore.kernel.org/r/20240615022641.210320-2-rafael@rcpassos.me
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-20 19:50:26 -07:00
Leon Hwang
f663a03c8e bpf, x64: Remove tail call detection
As 'prog->aux->tail_call_reachable' is correct for tail call present,
it's unnecessary to detect tail call in x86 jit.

Therefore, let's remove it.

Signed-off-by: Leon Hwang <hffilwlqm@gmail.com>
Link: https://lore.kernel.org/r/20240610124224.34673-3-hffilwlqm@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-20 19:48:29 -07:00
Jakub Kicinski
e958da0ddb Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

include/linux/filter.h
kernel/bpf/core.c
  66e13b615a ("bpf: verifier: prevent userspace memory access")
  d503a04f8b ("bpf: Add support for certain atomics in bpf_arena to x86 JIT")
https://lore.kernel.org/all/20240429114939.210328b0@canb.auug.org.au/

No adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-02 12:06:25 -07:00
Jakub Kicinski
89de2db193 bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-04-29

We've added 147 non-merge commits during the last 32 day(s) which contain
a total of 158 files changed, 9400 insertions(+), 2213 deletions(-).

The main changes are:

1) Add an internal-only BPF per-CPU instruction for resolving per-CPU
   memory addresses and implement support in x86 BPF JIT. This allows
   inlining per-CPU array and hashmap lookups
   and the bpf_get_smp_processor_id() helper, from Andrii Nakryiko.

2) Add BPF link support for sk_msg and sk_skb programs, from Yonghong Song.

3) Optimize x86 BPF JIT's emit_mov_imm64, and add support for various
   atomics in bpf_arena which can be JITed as a single x86 instruction,
   from Alexei Starovoitov.

4) Add support for passing mark with bpf_fib_lookup helper,
   from Anton Protopopov.

5) Add a new bpf_wq API for deferring events and refactor sleepable
   bpf_timer code to keep common code where possible,
   from Benjamin Tissoires.

6) Fix BPF_PROG_TEST_RUN infra with regards to bpf_dummy_struct_ops programs
   to check when NULL is passed for non-NULLable parameters,
   from Eduard Zingerman.

7) Harden the BPF verifier's and/or/xor value tracking,
   from Harishankar Vishwanathan.

8) Introduce crypto kfuncs to make BPF programs able to utilize the kernel
   crypto subsystem, from Vadim Fedorenko.

9) Various improvements to the BPF instruction set standardization doc,
   from Dave Thaler.

10) Extend libbpf APIs to partially consume items from the BPF ringbuffer,
    from Andrea Righi.

11) Bigger batch of BPF selftests refactoring to use common network helpers
    and to drop duplicate code, from Geliang Tang.

12) Support bpf_tail_call_static() helper for BPF programs with GCC 13,
    from Jose E. Marchesi.

13) Add bpf_preempt_{disable,enable}() kfuncs in order to allow a BPF
    program to have code sections where preemption is disabled,
    from Kumar Kartikeya Dwivedi.

14) Allow invoking BPF kfuncs from BPF_PROG_TYPE_SYSCALL programs,
    from David Vernet.

15) Extend the BPF verifier to allow different input maps for a given
    bpf_for_each_map_elem() helper call in a BPF program, from Philo Lu.

16) Add support for PROBE_MEM32 and bpf_addr_space_cast instructions
    for riscv64 and arm64 JITs to enable BPF Arena, from Puranjay Mohan.

17) Shut up a false-positive KMSAN splat in interpreter mode by unpoison
    the stack memory, from Martin KaFai Lau.

18) Improve xsk selftest coverage with new tests on maximum and minimum
    hardware ring size configurations, from Tushar Vyavahare.

19) Various ReST man pages fixes as well as documentation and bash completion
    improvements for bpftool, from Rameez Rehman & Quentin Monnet.

20) Fix libbpf with regards to dumping subsequent char arrays,
    from Quentin Deslandes.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (147 commits)
  bpf, docs: Clarify PC use in instruction-set.rst
  bpf_helpers.h: Define bpf_tail_call_static when building with GCC
  bpf, docs: Add introduction for use in the ISA Internet Draft
  selftests/bpf: extend BPF_SOCK_OPS_RTT_CB test for srtt and mrtt_us
  bpf: add mrtt and srtt as BPF_SOCK_OPS_RTT_CB args
  selftests/bpf: dummy_st_ops should reject 0 for non-nullable params
  bpf: check bpf_dummy_struct_ops program params for test runs
  selftests/bpf: do not pass NULL for non-nullable params in dummy_st_ops
  selftests/bpf: adjust dummy_st_ops_success to detect additional error
  bpf: mark bpf_dummy_struct_ops.test_1 parameter as nullable
  selftests/bpf: Add ring_buffer__consume_n test.
  bpf: Add bpf_guard_preempt() convenience macro
  selftests: bpf: crypto: add benchmark for crypto functions
  selftests: bpf: crypto skcipher algo selftests
  bpf: crypto: add skcipher to bpf crypto
  bpf: make common crypto API for TC/XDP programs
  bpf: update the comment for BTF_FIELDS_MAX
  selftests/bpf: Fix wq test.
  selftests/bpf: Use make_sockaddr in test_sock_addr
  selftests/bpf: Use connect_to_addr in test_sock_addr
  ...
====================

Link: https://lore.kernel.org/r/20240429131657.19423-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-29 13:12:19 -07:00
Puranjay Mohan
b599d7d26d bpf, x86: Fix PROBE_MEM runtime load check
When a load is marked PROBE_MEM - e.g. due to PTR_UNTRUSTED access - the
address being loaded from is not necessarily valid. The BPF jit sets up
exception handlers for each such load which catch page faults and 0 out
the destination register.

If the address for the load is outside kernel address space, the load
will escape the exception handling and crash the kernel. To prevent this
from happening, the emits some instruction to verify that addr is > end
of userspace addresses.

x86 has a legacy vsyscall ABI where a page at address 0xffffffffff600000
is mapped with user accessible permissions. The addresses in this page
are considered userspace addresses by the fault handler. Therefore, a
BPF program accessing this page will crash the kernel.

This patch fixes the runtime checks to also check that the PROBE_MEM
address is below VSYSCALL_ADDR.

Example BPF program:

 SEC("fentry/tcp_v4_connect")
 int BPF_PROG(fentry_tcp_v4_connect, struct sock *sk)
 {
	*(volatile unsigned long *)&sk->sk_tsq_flags;
	return 0;
 }

BPF Assembly:

 0: (79) r1 = *(u64 *)(r1 +0)
 1: (79) r1 = *(u64 *)(r1 +344)
 2: (b7) r0 = 0
 3: (95) exit

			       x86-64 JIT
			       ==========

            BEFORE                                    AFTER
	    ------                                    -----

 0:   nopl   0x0(%rax,%rax,1)             0:   nopl   0x0(%rax,%rax,1)
 5:   xchg   %ax,%ax                      5:   xchg   %ax,%ax
 7:   push   %rbp                         7:   push   %rbp
 8:   mov    %rsp,%rbp                    8:   mov    %rsp,%rbp
 b:   mov    0x0(%rdi),%rdi               b:   mov    0x0(%rdi),%rdi
-------------------------------------------------------------------------------
 f:   movabs $0x100000000000000,%r11      f:   movabs $0xffffffffff600000,%r10
19:   add    $0x2a0,%rdi                 19:   mov    %rdi,%r11
20:   cmp    %r11,%rdi                   1c:   add    $0x2a0,%r11
23:   jae    0x0000000000000029          23:   sub    %r10,%r11
25:   xor    %edi,%edi                   26:   movabs $0x100000000a00000,%r10
27:   jmp    0x000000000000002d          30:   cmp    %r10,%r11
29:   mov    0x0(%rdi),%rdi              33:   ja     0x0000000000000039
--------------------------------\        35:   xor    %edi,%edi
2d:   xor    %eax,%eax           \       37:   jmp    0x0000000000000040
2f:   leave                       \      39:   mov    0x2a0(%rdi),%rdi
30:   ret                          \--------------------------------------------
                                         40:   xor    %eax,%eax
                                         42:   leave
                                         43:   ret

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Link: https://lore.kernel.org/r/20240424100210.11982-3-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-26 09:45:18 -07:00
Puranjay Mohan
66e13b615a bpf: verifier: prevent userspace memory access
With BPF_PROBE_MEM, BPF allows de-referencing an untrusted pointer. To
thwart invalid memory accesses, the JITs add an exception table entry
for all such accesses. But in case the src_reg + offset is a userspace
address, the BPF program might read that memory if the user has
mapped it.

Make the verifier add guard instructions around such memory accesses and
skip the load if the address falls into the userspace region.

The JITs need to implement bpf_arch_uaddress_limit() to define where
the userspace addresses end for that architecture or TASK_SIZE is taken
as default.

The implementation is as follows:

REG_AX =  SRC_REG
if(offset)
	REG_AX += offset;
REG_AX >>= 32;
if (REG_AX <= (uaddress_limit >> 32))
	DST_REG = 0;
else
	DST_REG = *(size *)(SRC_REG + offset);

Comparing just the upper 32 bits of the load address with the upper
32 bits of uaddress_limit implies that the values are being aligned down
to a 4GB boundary before comparison.

The above means that all loads with address <= uaddress_limit + 4GB are
skipped. This is acceptable because there is a large hole (much larger
than 4GB) between userspace and kernel space memory, therefore a
correctly functioning BPF program should not access this 4GB memory
above the userspace.

Let's analyze what this patch does to the following fentry program
dereferencing an untrusted pointer:

  SEC("fentry/tcp_v4_connect")
  int BPF_PROG(fentry_tcp_v4_connect, struct sock *sk)
  {
                *(volatile long *)sk;
                return 0;
  }

    BPF Program before              |           BPF Program after
    ------------------              |           -----------------

  0: (79) r1 = *(u64 *)(r1 +0)          0: (79) r1 = *(u64 *)(r1 +0)
  -----------------------------------------------------------------------
  1: (79) r1 = *(u64 *)(r1 +0) --\      1: (bf) r11 = r1
  ----------------------------\   \     2: (77) r11 >>= 32
  2: (b7) r0 = 0               \   \    3: (b5) if r11 <= 0x8000 goto pc+2
  3: (95) exit                  \   \-> 4: (79) r1 = *(u64 *)(r1 +0)
                                 \      5: (05) goto pc+1
                                  \     6: (b7) r1 = 0
                                   \--------------------------------------
                                        7: (b7) r0 = 0
                                        8: (95) exit

As you can see from above, in the best case (off=0), 5 extra instructions
are emitted.

Now, we analyze the same program after it has gone through the JITs of
ARM64 and RISC-V architectures. We follow the single load instruction
that has the untrusted pointer and see what instrumentation has been
added around it.

                                x86-64 JIT
                                ==========
     JIT's Instrumentation
          (upstream)
     ---------------------

   0:   nopl   0x0(%rax,%rax,1)
   5:   xchg   %ax,%ax
   7:   push   %rbp
   8:   mov    %rsp,%rbp
   b:   mov    0x0(%rdi),%rdi
  ---------------------------------
   f:   movabs $0x800000000000,%r11
  19:   cmp    %r11,%rdi
  1c:   jb     0x000000000000002a
  1e:   mov    %rdi,%r11
  21:   add    $0x0,%r11
  28:   jae    0x000000000000002e
  2a:   xor    %edi,%edi
  2c:   jmp    0x0000000000000032
  2e:   mov    0x0(%rdi),%rdi
  ---------------------------------
  32:   xor    %eax,%eax
  34:   leave
  35:   ret

The x86-64 JIT already emits some instructions to protect against user
memory access. This patch doesn't make any changes for the x86-64 JIT.

                                  ARM64 JIT
                                  =========

        No Intrumentation                       Verifier's Instrumentation
           (upstream)                                  (This patch)
        -----------------                       --------------------------

   0:   add     x9, x30, #0x0                0:   add     x9, x30, #0x0
   4:   nop                                  4:   nop
   8:   paciasp                              8:   paciasp
   c:   stp     x29, x30, [sp, #-16]!        c:   stp     x29, x30, [sp, #-16]!
  10:   mov     x29, sp                     10:   mov     x29, sp
  14:   stp     x19, x20, [sp, #-16]!       14:   stp     x19, x20, [sp, #-16]!
  18:   stp     x21, x22, [sp, #-16]!       18:   stp     x21, x22, [sp, #-16]!
  1c:   stp     x25, x26, [sp, #-16]!       1c:   stp     x25, x26, [sp, #-16]!
  20:   stp     x27, x28, [sp, #-16]!       20:   stp     x27, x28, [sp, #-16]!
  24:   mov     x25, sp                     24:   mov     x25, sp
  28:   mov     x26, #0x0                   28:   mov     x26, #0x0
  2c:   sub     x27, x25, #0x0              2c:   sub     x27, x25, #0x0
  30:   sub     sp, sp, #0x0                30:   sub     sp, sp, #0x0
  34:   ldr     x0, [x0]                    34:   ldr     x0, [x0]
--------------------------------------------------------------------------------
  38:   ldr     x0, [x0] ----------\        38:   add     x9, x0, #0x0
-----------------------------------\\       3c:   lsr     x9, x9, #32
  3c:   mov     x7, #0x0            \\      40:   cmp     x9, #0x10, lsl #12
  40:   mov     sp, sp               \\     44:   b.ls    0x0000000000000050
  44:   ldp     x27, x28, [sp], #16   \\--> 48:   ldr     x0, [x0]
  48:   ldp     x25, x26, [sp], #16    \    4c:   b       0x0000000000000054
  4c:   ldp     x21, x22, [sp], #16     \   50:   mov     x0, #0x0
  50:   ldp     x19, x20, [sp], #16      \---------------------------------------
  54:   ldp     x29, x30, [sp], #16         54:   mov     x7, #0x0
  58:   add     x0, x7, #0x0                58:   mov     sp, sp
  5c:   autiasp                             5c:   ldp     x27, x28, [sp], #16
  60:   ret                                 60:   ldp     x25, x26, [sp], #16
  64:   nop                                 64:   ldp     x21, x22, [sp], #16
  68:   ldr     x10, 0x0000000000000070     68:   ldp     x19, x20, [sp], #16
  6c:   br      x10                         6c:   ldp     x29, x30, [sp], #16
                                            70:   add     x0, x7, #0x0
                                            74:   autiasp
                                            78:   ret
                                            7c:   nop
                                            80:   ldr     x10, 0x0000000000000088
                                            84:   br      x10

There are 6 extra instructions added in ARM64 in the best case. This will
become 7 in the worst case (off != 0).

                           RISC-V JIT (RISCV_ISA_C Disabled)
                           ==========

        No Intrumentation           Verifier's Instrumentation
           (upstream)                      (This patch)
        -----------------           --------------------------

   0:   nop                            0:   nop
   4:   nop                            4:   nop
   8:   li      a6, 33                 8:   li      a6, 33
   c:   addi    sp, sp, -16            c:   addi    sp, sp, -16
  10:   sd      s0, 8(sp)             10:   sd      s0, 8(sp)
  14:   addi    s0, sp, 16            14:   addi    s0, sp, 16
  18:   ld      a0, 0(a0)             18:   ld      a0, 0(a0)
---------------------------------------------------------------
  1c:   ld      a0, 0(a0) --\         1c:   mv      t0, a0
--------------------------\  \        20:   srli    t0, t0, 32
  20:   li      a5, 0      \  \       24:   lui     t1, 4096
  24:   ld      s0, 8(sp)   \  \      28:   sext.w  t1, t1
  28:   addi    sp, sp, 16   \  \     2c:   bgeu    t1, t0, 12
  2c:   sext.w  a0, a5        \  \--> 30:   ld      a0, 0(a0)
  30:   ret                    \      34:   j       8
                                \     38:   li      a0, 0
                                 \------------------------------
                                      3c:   li      a5, 0
                                      40:   ld      s0, 8(sp)
                                      44:   addi    sp, sp, 16
                                      48:   sext.w  a0, a5
                                      4c:   ret

There are 7 extra instructions added in RISC-V.

Fixes: 8008342853 ("bpf, arm64: Add BPF exception tables")
Reported-by: Breno Leitao <leitao@debian.org>
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Link: https://lore.kernel.org/r/20240424100210.11982-2-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-26 09:45:18 -07:00
Alexei Starovoitov
462e5e2a59 bpf: Fix JIT of is_mov_percpu_addr instruction.
The codegen for is_mov_percpu_addr instruction works for rax/r8 registers
only. Fix it to generate proper x86 byte code for other registers.

Fixes: 7bdbf74463 ("bpf: add special internal-only MOV instruction to resolve per-CPU addrs")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240417214406.15788-1-alexei.starovoitov@gmail.com
2024-04-18 09:03:21 -07:00
Alexei Starovoitov
d503a04f8b bpf: Add support for certain atomics in bpf_arena to x86 JIT
Support atomics in bpf_arena that can be JITed as a single x86 instruction.
Instructions that are JITed as loops are not supported at the moment,
since they require more complex extable and loop logic.

JITs can choose to do smarter things with bpf_jit_supports_insn().
Like arm64 may decide to support all bpf atomics instructions
when emit_lse_atomic is available and none in ll_sc mode.

bpf_jit_supports_percpu_insn(), bpf_jit_supports_ptr_xchg() and
other such callbacks can be replaced with bpf_jit_supports_insn()
in the future.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240405231134.17274-1-alexei.starovoitov@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-04-09 10:24:26 -07:00
Jakub Kicinski
cf1ca1f66d Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

net/ipv4/ip_gre.c
  17af420545 ("erspan: make sure erspan_base_hdr is present in skb->head")
  5832c4a77d ("ip_tunnel: convert __be16 tunnel flags to bitmaps")
https://lore.kernel.org/all/20240402103253.3b54a1cf@canb.auug.org.au/

Adjacent changes:

net/ipv6/ip6_fib.c
  d21d40605b ("ipv6: Fix infinite recursion in fib6_dump_done().")
  5fc68320c1 ("ipv6: remove RTNL protection from inet6_dump_fib()")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-04 18:01:07 -07:00
Alexei Starovoitov
af682b767a bpf: Optimize emit_mov_imm64().
Turned out that bpf prog callback addresses, bpf prog addresses
used in bpf_trampoline, and in other cases the 64-bit address
can be represented as sign extended 32-bit value.

According to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82339
"Skylake has 0.64c throughput for mov r64, imm64, vs. 0.25 for mov r32, imm32."
So use shorter encoding and faster instruction when possible.

Special care is needed in jit_subprogs(), since bpf_pseudo_func()
instruction cannot change its size during the last step of JIT.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/CAADnVQKFfpY-QZBrOU2CG8v2du8Lgyb7MNVmOZVK_yTyOdNbBA@mail.gmail.com
Link: https://lore.kernel.org/bpf/20240401233800.42737-1-alexei.starovoitov@gmail.com
2024-04-04 16:13:26 +02:00
Andrii Nakryiko
1e9e0b8525 bpf: handle CONFIG_SMP=n configuration in x86 BPF JIT
On non-SMP systems, there is no "per-CPU" data, it's just global data.
So in such case just don't do this_cpu_off-based per-CPU address adjustment.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202404040951.d4CUx5S6-lkp@intel.com/
Fixes: 7bdbf74463 ("bpf: add special internal-only MOV instruction to resolve per-CPU addrs")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240404034726.2766740-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-03 21:36:35 -07:00
Andrii Nakryiko
7bdbf74463 bpf: add special internal-only MOV instruction to resolve per-CPU addrs
Add a new BPF instruction for resolving absolute addresses of per-CPU
data from their per-CPU offsets. This instruction is internal-only and
users are not allowed to use them directly. They will only be used for
internal inlining optimizations for now between BPF verifier and BPF JITs.

We use a special BPF_MOV | BPF_ALU64 | BPF_X form with insn->off field
set to BPF_ADDR_PERCPU = -1. I used negative offset value to distinguish
them from positive ones used by user-exposed instructions.

Such instruction performs a resolution of a per-CPU offset stored in
a register to a valid kernel address which can be dereferenced. It is
useful in any use case where absolute address of a per-CPU data has to
be resolved (e.g., in inlining bpf_map_lookup_elem()).

BPF disassembler is also taught to recognize them to support dumping
final BPF assembly code (non-JIT'ed version).

Add arch-specific way for BPF JITs to mark support for this instructions.

This patch also adds support for these instructions in x86-64 BPF JIT.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20240402021307.1012571-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-03 10:29:55 -07:00
Joan Bruguera Micó
6a53745300 x86/bpf: Fix IP for relocating call depth accounting
The commit:

  59bec00ace ("x86/percpu: Introduce %rip-relative addressing to PER_CPU_VAR()")

made PER_CPU_VAR() to use rip-relative addressing, hence
INCREMENT_CALL_DEPTH macro and skl_call_thunk_template got rip-relative
asm code inside of it. A follow up commit:

  17bce3b2ae ("x86/callthunks: Handle %rip-relative relocations in call thunk template")

changed x86_call_depth_emit_accounting() to use apply_relocation(),
but mistakenly assumed that the code is being patched in-place (where
the destination of the relocation matches the address of the code),
using *pprog as the destination ip. This is not true for the call depth
accounting, emitted by the BPF JIT, so the calculated address was wrong,
JIT-ed BPF progs on kernels with call depth tracking got broken and
usually caused a page fault.

Pass the destination IP when the BPF JIT emits call depth accounting.

Fixes: 17bce3b2ae ("x86/callthunks: Handle %rip-relative relocations in call thunk template")
Signed-off-by: Joan Bruguera Micó <joanbrugueram@gmail.com>
Reviewed-by: Uros Bizjak <ubizjak@gmail.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20240401185821.224068-3-ubizjak@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-01 20:37:56 -07:00
Uros Bizjak
9d98aa0883 x86/bpf: Fix IP after emitting call depth accounting
Adjust the IP passed to `emit_patch` so it calculates the correct offset
for the CALL instruction if `x86_call_depth_emit_accounting` emits code.
Otherwise we will skip some instructions and most likely crash.

Fixes: b2e9dfe54b ("x86/bpf: Emit call depth accounting if required")
Link: https://lore.kernel.org/lkml/20230105214922.250473-1-joanbrugueram@gmail.com/
Co-developed-by: Joan Bruguera Micó <joanbrugueram@gmail.com>
Signed-off-by: Joan Bruguera Micó <joanbrugueram@gmail.com>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20240401185821.224068-2-ubizjak@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-01 20:37:56 -07:00
Puranjay Mohan
770546ae9f bpf: implement insn_is_cast_user() helper for JITs
Implement a helper function to check if an instruction is
addr_space_cast from as(0) to as(1). Use this helper in the x86 JIT.

Other JITs can use this helper when they add support for this instruction.

Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Link: https://lore.kernel.org/r/20240324183226.29674-1-puranjay12@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-25 09:10:51 -07:00
Christophe Leroy
c733239f8f bpf: Check return from set_memory_rox()
arch_protect_bpf_trampoline() and alloc_new_pack() call
set_memory_rox() which can fail, leading to unprotected memory.

Take into account return from set_memory_rox() function and add
__must_check flag to arch_protect_bpf_trampoline().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/fe1c163c83767fde5cab31d209a4a6be3ddb3a73.1710574353.git.christophe.leroy@csgroup.eu
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-03-18 14:18:47 -07:00
Christophe Leroy
e3362acd79 bpf: Remove arch_unprotect_bpf_trampoline()
Last user of arch_unprotect_bpf_trampoline() was removed by
commit 187e2af05a ("bpf: struct_ops supports more than one page for
trampolines.")

Remove arch_unprotect_bpf_trampoline()

Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Fixes: 187e2af05a ("bpf: struct_ops supports more than one page for trampolines.")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/r/42c635bb54d3af91db0f9b85d724c7c290069f67.1710574353.git.christophe.leroy@csgroup.eu
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-03-18 14:18:47 -07:00
Linus Torvalds
9187210eee Networking changes for 6.9.
Core & protocols
 ----------------
 
  - Large effort by Eric to lower rtnl_lock pressure and remove locks:
 
    - Make commonly used parts of rtnetlink (address, route dumps etc.)
      lockless, protected by RCU instead of rtnl_lock.
 
    - Add a netns exit callback which already holds rtnl_lock,
      allowing netns exit to take rtnl_lock once in the core
      instead of once for each driver / callback.
 
    - Remove locks / serialization in the socket diag interface.
 
    - Remove 6 calls to synchronize_rcu() while holding rtnl_lock.
 
    - Remove the dev_base_lock, depend on RCU where necessary.
 
  - Support busy polling on a per-epoll context basis. Poll length
    and budget parameters can be set independently of system defaults.
 
  - Introduce struct net_hotdata, to make sure read-mostly global config
    variables fit in as few cache lines as possible.
 
  - Add optional per-nexthop statistics to ease monitoring / debug
    of ECMP imbalance problems.
 
  - Support TCP_NOTSENT_LOWAT in MPTCP.
 
  - Ensure that IPv6 temporary addresses' preferred lifetimes are long
    enough, compared to other configured lifetimes, and at least 2 sec.
 
  - Support forwarding of ICMP Error messages in IPSec, per RFC 4301.
 
  - Add support for the independent control state machine for bonding
    per IEEE 802.1AX-2008 5.4.15 in addition to the existing coupled
    control state machine.
 
  - Add "network ID" to MCTP socket APIs to support hosts with multiple
    disjoint MCTP networks.
 
  - Re-use the mono_delivery_time skbuff bit for packets which user
    space wants to be sent at a specified time. Maintain the timing
    information while traversing veth links, bridge etc.
 
  - Take advantage of MSG_SPLICE_PAGES for RxRPC DATA and ACK packets.
 
  - Simplify many places iterating over netdevs by using an xarray
    instead of a hash table walk (hash table remains in place, for
    use on fastpaths).
 
  - Speed up scanning for expired routes by keeping a dedicated list.
 
  - Speed up "generic" XDP by trying harder to avoid large allocations.
 
  - Support attaching arbitrary metadata to netconsole messages.
 
 Things we sprinkled into general kernel code
 --------------------------------------------
 
  - Enforce VM_IOREMAP flag and range in ioremap_page_range and introduce
    VM_SPARSE kind and vm_area_[un]map_pages (used by bpf_arena).
 
  - Rework selftest harness to enable the use of the full range of
    ksft exit code (pass, fail, skip, xfail, xpass).
 
 Netfilter
 ---------
 
  - Allow userspace to define a table that is exclusively owned by a daemon
    (via netlink socket aliveness) without auto-removing this table when
    the userspace program exits. Such table gets marked as orphaned and
    a restarting management daemon can re-attach/regain ownership.
 
  - Speed up element insertions to nftables' concatenated-ranges set type.
    Compact a few related data structures.
 
 BPF
 ---
 
  - Add BPF token support for delegating a subset of BPF subsystem
    functionality from privileged system-wide daemons such as systemd
    through special mount options for userns-bound BPF fs to a trusted
    & unprivileged application.
 
  - Introduce bpf_arena which is sparse shared memory region between BPF
    program and user space where structures inside the arena can have
    pointers to other areas of the arena, and pointers work seamlessly
    for both user-space programs and BPF programs.
 
  - Introduce may_goto instruction that is a contract between the verifier
    and the program. The verifier allows the program to loop assuming it's
    behaving well, but reserves the right to terminate it.
 
  - Extend the BPF verifier to enable static subprog calls in spin lock
    critical sections.
 
  - Support registration of struct_ops types from modules which helps
    projects like fuse-bpf that seeks to implement a new struct_ops type.
 
  - Add support for retrieval of cookies for perf/kprobe multi links.
 
  - Support arbitrary TCP SYN cookie generation / validation in the TC
    layer with BPF to allow creating SYN flood handling in BPF firewalls.
 
  - Add code generation to inline the bpf_kptr_xchg() helper which
    improves performance when stashing/popping the allocated BPF objects.
 
 Wireless
 --------
 
  - Add SPP (signaling and payload protected) AMSDU support.
 
  - Support wider bandwidth OFDMA, as required for EHT operation.
 
 Driver API
 ----------
 
  - Major overhaul of the Energy Efficient Ethernet internals to support
    new link modes (2.5GE, 5GE), share more code between drivers
    (especially those using phylib), and encourage more uniform behavior.
    Convert and clean up drivers.
 
  - Define an API for querying per netdev queue statistics from drivers.
 
  - IPSec: account in global stats for fully offloaded sessions.
 
  - Create a concept of Ethernet PHY Packages at the Device Tree level,
    to allow parameterizing the existing PHY package code.
 
  - Enable Rx hashing (RSS) on GTP protocol fields.
 
 Misc
 ----
 
  - Improvements and refactoring all over networking selftests.
 
  - Create uniform module aliases for TC classifiers, actions,
    and packet schedulers to simplify creating modprobe policies.
 
  - Address all missing MODULE_DESCRIPTION() warnings in networking.
 
  - Extend the Netlink descriptions in YAML to cover message encapsulation
    or "Netlink polymorphism", where interpretation of nested attributes
    depends on link type, classifier type or some other "class type".
 
 Drivers
 -------
 
  - Ethernet high-speed NICs:
    - Add a new driver for Marvell's Octeon PCI Endpoint NIC VF.
    - Intel (100G, ice, idpf):
      - support E825-C devices
    - nVidia/Mellanox:
      - support devices with one port and multiple PCIe links
    - Broadcom (bnxt):
      - support n-tuple filters
      - support configuring the RSS key
    - Wangxun (ngbe/txgbe):
      - implement irq_domain for TXGBE's sub-interrupts
    - Pensando/AMD:
      - support XDP
      - optimize queue submission and wakeup handling (+17% bps)
      - optimize struct layout, saving 28% of memory on queues
 
  - Ethernet NICs embedded and virtual:
    - Google cloud vNIC:
      - refactor driver to perform memory allocations for new queue
        config before stopping and freeing the old queue memory
    - Synopsys (stmmac):
      - obey queueMaxSDU and implement counters required by 802.1Qbv
    - Renesas (ravb):
      - support packet checksum offload
      - suspend to RAM and runtime PM support
 
  - Ethernet switches:
    - nVidia/Mellanox:
      - support for nexthop group statistics
    - Microchip:
      - ksz8: implement PHY loopback
      - add support for KSZ8567, a 7-port 10/100Mbps switch
 
  - PTP:
    - New driver for RENESAS FemtoClock3 Wireless clock generator.
    - Support OCP PTP cards designed and built by Adva.
 
  - CAN:
    - Support recvmsg() flags for own, local and remote traffic
      on CAN BCM sockets.
    - Support for esd GmbH PCIe/402 CAN device family.
    - m_can:
      - Rx/Tx submission coalescing
      - wake on frame Rx
 
  - WiFi:
    - Intel (iwlwifi):
      - enable signaling and payload protected A-MSDUs
      - support wider-bandwidth OFDMA
      - support for new devices
      - bump FW API to 89 for AX devices; 90 for BZ/SC devices
    - MediaTek (mt76):
      - mt7915: newer ADIE version support
      - mt7925: radio temperature sensor support
    - Qualcomm (ath11k):
      - support 6 GHz station power modes: Low Power Indoor (LPI),
        Standard Power) SP and Very Low Power (VLP)
      - QCA6390 & WCN6855: support 2 concurrent station interfaces
      - QCA2066 support
    - Qualcomm (ath12k):
      - refactoring in preparation for Multi-Link Operation (MLO) support
      - 1024 Block Ack window size support
      - firmware-2.bin support
      - support having multiple identical PCI devices (firmware needs to
        have ATH12K_FW_FEATURE_MULTI_QRTR_ID)
      - QCN9274: support split-PHY devices
      - WCN7850: enable Power Save Mode in station mode
      - WCN7850: P2P support
    - RealTek:
      - rtw88: support for more rtw8811cu and rtw8821cu devices
      - rtw89: support SCAN_RANDOM_SN and SET_SCAN_DWELL
      - rtlwifi: speed up USB firmware initialization
      - rtwl8xxxu:
        - RTL8188F: concurrent interface support
        - Channel Switch Announcement (CSA) support in AP mode
    - Broadcom (brcmfmac):
      - per-vendor feature support
      - per-vendor SAE password setup
      - DMI nvram filename quirk for ACEPC W5 Pro
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core & protocols:

   - Large effort by Eric to lower rtnl_lock pressure and remove locks:

      - Make commonly used parts of rtnetlink (address, route dumps
        etc) lockless, protected by RCU instead of rtnl_lock.

      - Add a netns exit callback which already holds rtnl_lock,
        allowing netns exit to take rtnl_lock once in the core instead
        of once for each driver / callback.

      - Remove locks / serialization in the socket diag interface.

      - Remove 6 calls to synchronize_rcu() while holding rtnl_lock.

      - Remove the dev_base_lock, depend on RCU where necessary.

   - Support busy polling on a per-epoll context basis. Poll length and
     budget parameters can be set independently of system defaults.

   - Introduce struct net_hotdata, to make sure read-mostly global
     config variables fit in as few cache lines as possible.

   - Add optional per-nexthop statistics to ease monitoring / debug of
     ECMP imbalance problems.

   - Support TCP_NOTSENT_LOWAT in MPTCP.

   - Ensure that IPv6 temporary addresses' preferred lifetimes are long
     enough, compared to other configured lifetimes, and at least 2 sec.

   - Support forwarding of ICMP Error messages in IPSec, per RFC 4301.

   - Add support for the independent control state machine for bonding
     per IEEE 802.1AX-2008 5.4.15 in addition to the existing coupled
     control state machine.

   - Add "network ID" to MCTP socket APIs to support hosts with multiple
     disjoint MCTP networks.

   - Re-use the mono_delivery_time skbuff bit for packets which user
     space wants to be sent at a specified time. Maintain the timing
     information while traversing veth links, bridge etc.

   - Take advantage of MSG_SPLICE_PAGES for RxRPC DATA and ACK packets.

   - Simplify many places iterating over netdevs by using an xarray
     instead of a hash table walk (hash table remains in place, for use
     on fastpaths).

   - Speed up scanning for expired routes by keeping a dedicated list.

   - Speed up "generic" XDP by trying harder to avoid large allocations.

   - Support attaching arbitrary metadata to netconsole messages.

  Things we sprinkled into general kernel code:

   - Enforce VM_IOREMAP flag and range in ioremap_page_range and
     introduce VM_SPARSE kind and vm_area_[un]map_pages (used by
     bpf_arena).

   - Rework selftest harness to enable the use of the full range of ksft
     exit code (pass, fail, skip, xfail, xpass).

  Netfilter:

   - Allow userspace to define a table that is exclusively owned by a
     daemon (via netlink socket aliveness) without auto-removing this
     table when the userspace program exits. Such table gets marked as
     orphaned and a restarting management daemon can re-attach/regain
     ownership.

   - Speed up element insertions to nftables' concatenated-ranges set
     type. Compact a few related data structures.

  BPF:

   - Add BPF token support for delegating a subset of BPF subsystem
     functionality from privileged system-wide daemons such as systemd
     through special mount options for userns-bound BPF fs to a trusted
     & unprivileged application.

   - Introduce bpf_arena which is sparse shared memory region between
     BPF program and user space where structures inside the arena can
     have pointers to other areas of the arena, and pointers work
     seamlessly for both user-space programs and BPF programs.

   - Introduce may_goto instruction that is a contract between the
     verifier and the program. The verifier allows the program to loop
     assuming it's behaving well, but reserves the right to terminate
     it.

   - Extend the BPF verifier to enable static subprog calls in spin lock
     critical sections.

   - Support registration of struct_ops types from modules which helps
     projects like fuse-bpf that seeks to implement a new struct_ops
     type.

   - Add support for retrieval of cookies for perf/kprobe multi links.

   - Support arbitrary TCP SYN cookie generation / validation in the TC
     layer with BPF to allow creating SYN flood handling in BPF
     firewalls.

   - Add code generation to inline the bpf_kptr_xchg() helper which
     improves performance when stashing/popping the allocated BPF
     objects.

  Wireless:

   - Add SPP (signaling and payload protected) AMSDU support.

   - Support wider bandwidth OFDMA, as required for EHT operation.

  Driver API:

   - Major overhaul of the Energy Efficient Ethernet internals to
     support new link modes (2.5GE, 5GE), share more code between
     drivers (especially those using phylib), and encourage more
     uniform behavior. Convert and clean up drivers.

   - Define an API for querying per netdev queue statistics from
     drivers.

   - IPSec: account in global stats for fully offloaded sessions.

   - Create a concept of Ethernet PHY Packages at the Device Tree level,
     to allow parameterizing the existing PHY package code.

   - Enable Rx hashing (RSS) on GTP protocol fields.

  Misc:

   - Improvements and refactoring all over networking selftests.

   - Create uniform module aliases for TC classifiers, actions, and
     packet schedulers to simplify creating modprobe policies.

   - Address all missing MODULE_DESCRIPTION() warnings in networking.

   - Extend the Netlink descriptions in YAML to cover message
     encapsulation or "Netlink polymorphism", where interpretation of
     nested attributes depends on link type, classifier type or some
     other "class type".

  Drivers:

   - Ethernet high-speed NICs:
      - Add a new driver for Marvell's Octeon PCI Endpoint NIC VF.
      - Intel (100G, ice, idpf):
         - support E825-C devices
      - nVidia/Mellanox:
         - support devices with one port and multiple PCIe links
      - Broadcom (bnxt):
         - support n-tuple filters
         - support configuring the RSS key
      - Wangxun (ngbe/txgbe):
         - implement irq_domain for TXGBE's sub-interrupts
      - Pensando/AMD:
         - support XDP
         - optimize queue submission and wakeup handling (+17% bps)
         - optimize struct layout, saving 28% of memory on queues

   - Ethernet NICs embedded and virtual:
      - Google cloud vNIC:
         - refactor driver to perform memory allocations for new queue
           config before stopping and freeing the old queue memory
      - Synopsys (stmmac):
         - obey queueMaxSDU and implement counters required by 802.1Qbv
      - Renesas (ravb):
         - support packet checksum offload
         - suspend to RAM and runtime PM support

   - Ethernet switches:
      - nVidia/Mellanox:
         - support for nexthop group statistics
      - Microchip:
         - ksz8: implement PHY loopback
         - add support for KSZ8567, a 7-port 10/100Mbps switch

   - PTP:
      - New driver for RENESAS FemtoClock3 Wireless clock generator.
      - Support OCP PTP cards designed and built by Adva.

   - CAN:
      - Support recvmsg() flags for own, local and remote traffic on CAN
        BCM sockets.
      - Support for esd GmbH PCIe/402 CAN device family.
      - m_can:
         - Rx/Tx submission coalescing
         - wake on frame Rx

   - WiFi:
      - Intel (iwlwifi):
         - enable signaling and payload protected A-MSDUs
         - support wider-bandwidth OFDMA
         - support for new devices
         - bump FW API to 89 for AX devices; 90 for BZ/SC devices
      - MediaTek (mt76):
         - mt7915: newer ADIE version support
         - mt7925: radio temperature sensor support
      - Qualcomm (ath11k):
         - support 6 GHz station power modes: Low Power Indoor (LPI),
           Standard Power) SP and Very Low Power (VLP)
         - QCA6390 & WCN6855: support 2 concurrent station interfaces
         - QCA2066 support
      - Qualcomm (ath12k):
         - refactoring in preparation for Multi-Link Operation (MLO)
           support
         - 1024 Block Ack window size support
         - firmware-2.bin support
         - support having multiple identical PCI devices (firmware needs
           to have ATH12K_FW_FEATURE_MULTI_QRTR_ID)
         - QCN9274: support split-PHY devices
         - WCN7850: enable Power Save Mode in station mode
         - WCN7850: P2P support
      - RealTek:
         - rtw88: support for more rtw8811cu and rtw8821cu devices
         - rtw89: support SCAN_RANDOM_SN and SET_SCAN_DWELL
         - rtlwifi: speed up USB firmware initialization
         - rtwl8xxxu:
             - RTL8188F: concurrent interface support
             - Channel Switch Announcement (CSA) support in AP mode
      - Broadcom (brcmfmac):
         - per-vendor feature support
         - per-vendor SAE password setup
         - DMI nvram filename quirk for ACEPC W5 Pro"

* tag 'net-next-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2255 commits)
  nexthop: Fix splat with CONFIG_DEBUG_PREEMPT=y
  nexthop: Fix out-of-bounds access during attribute validation
  nexthop: Only parse NHA_OP_FLAGS for dump messages that require it
  nexthop: Only parse NHA_OP_FLAGS for get messages that require it
  bpf: move sleepable flag from bpf_prog_aux to bpf_prog
  bpf: hardcode BPF_PROG_PACK_SIZE to 2MB * num_possible_nodes()
  selftests/bpf: Add kprobe multi triggering benchmarks
  ptp: Move from simple ida to xarray
  vxlan: Remove generic .ndo_get_stats64
  vxlan: Do not alloc tstats manually
  devlink: Add comments to use netlink gen tool
  nfp: flower: handle acti_netdevs allocation failure
  net/packet: Add getsockopt support for PACKET_COPY_THRESH
  net/netlink: Add getsockopt support for NETLINK_LISTEN_ALL_NSID
  selftests/bpf: Add bpf_arena_htab test.
  selftests/bpf: Add bpf_arena_list test.
  selftests/bpf: Add unit tests for bpf_arena_alloc/free_pages
  bpf: Add helper macro bpf_addr_space_cast()
  libbpf: Recognize __arena global variables.
  bpftool: Recognize arena map type
  ...
2024-03-12 17:44:08 -07:00
Alexei Starovoitov
142fd4d2dc bpf: Add x86-64 JIT support for bpf_addr_space_cast instruction.
LLVM generates bpf_addr_space_cast instruction while translating
pointers between native (zero) address space and
__attribute__((address_space(N))).
The addr_space=1 is reserved as bpf_arena address space.

rY = addr_space_cast(rX, 0, 1) is processed by the verifier and
converted to normal 32-bit move: wX = wY

rY = addr_space_cast(rX, 1, 0) has to be converted by JIT:

aux_reg = upper_32_bits of arena->user_vm_start
aux_reg <<= 32
wX = wY // clear upper 32 bits of dst register
if (wX) // if not zero add upper bits of user_vm_start
  wX |= aux_reg

JIT can do it more efficiently:

mov dst_reg32, src_reg32  // 32-bit move
shl dst_reg, 32
or dst_reg, user_vm_start
rol dst_reg, 32
xor r11, r11
test dst_reg32, dst_reg32 // check if lower 32-bit are zero
cmove r11, dst_reg	  // if so, set dst_reg to zero
			  // Intel swapped src/dst register encoding in CMOVcc

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240308010812.89848-5-alexei.starovoitov@gmail.com
2024-03-11 15:37:24 -07:00
Alexei Starovoitov
2fe99eb0cc bpf: Add x86-64 JIT support for PROBE_MEM32 pseudo instructions.
Add support for [LDX | STX | ST], PROBE_MEM32, [B | H | W | DW] instructions.
They are similar to PROBE_MEM instructions with the following differences:
- PROBE_MEM has to check that the address is in the kernel range with
  src_reg + insn->off >= TASK_SIZE_MAX + PAGE_SIZE check
- PROBE_MEM doesn't support store
- PROBE_MEM32 relies on the verifier to clear upper 32-bit in the register
- PROBE_MEM32 adds 64-bit kern_vm_start address (which is stored in %r12 in the prologue)
  Due to bpf_arena constructions such %r12 + %reg + off16 access is guaranteed
  to be within arena virtual range, so no address check at run-time.
- PROBE_MEM32 allows STX and ST. If they fault the store is a nop.
  When LDX faults the destination register is zeroed.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20240308010812.89848-4-alexei.starovoitov@gmail.com
2024-03-11 15:37:24 -07:00
Ingo Molnar
4589f199eb Merge branch 'x86/bugs' into x86/core, to pick up pending changes before dependent patches
Merge in pending alternatives patching infrastructure changes, before
applying more patches.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-02-14 10:49:37 +01:00
Hou Tao
7c05e7f3e7 bpf: Support inlining bpf_kptr_xchg() helper
The motivation of inlining bpf_kptr_xchg() comes from the performance
profiling of bpf memory allocator benchmark. The benchmark uses
bpf_kptr_xchg() to stash the allocated objects and to pop the stashed
objects for free. After inling bpf_kptr_xchg(), the performance for
object free on 8-CPUs VM increases about 2%~10%. The inline also has
downside: both the kasan and kcsan checks on the pointer will be
unavailable.

bpf_kptr_xchg() can be inlined by converting the calling of
bpf_kptr_xchg() into an atomic_xchg() instruction. But the conversion
depends on two conditions:
1) JIT backend supports atomic_xchg() on pointer-sized word
2) For the specific arch, the implementation of xchg is the same as
   atomic_xchg() on pointer-sized words.

It seems most 64-bit JIT backends satisfies these two conditions. But
as a precaution, defining a weak function bpf_jit_supports_ptr_xchg()
to state whether such conversion is safe and only supporting inline for
64-bit host.

For x86-64, it supports BPF_XCHG atomic operation and both xchg() and
atomic_xchg() use arch_xchg() to implement the exchange, so enabling the
inline of bpf_kptr_xchg() on x86-64 first.

Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20240105104819.3916743-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-01-23 14:40:21 -08:00
Linus Torvalds
3e7aeb78ab Networking changes for 6.8.
Core & protocols
 ----------------
 
  - Analyze and reorganize core networking structs (socks, netdev,
    netns, mibs) to optimize cacheline consumption and set up
    build time warnings to safeguard against future header changes.
    This improves TCP performances with many concurrent connections
    up to 40%.
 
  - Add page-pool netlink-based introspection, exposing the
    memory usage and recycling stats. This helps indentify
    bad PP users and possible leaks.
 
  - Refine TCP/DCCP source port selection to no longer favor even
    source port at connect() time when IP_LOCAL_PORT_RANGE is set.
    This lowers the time taken by connect() for hosts having
    many active connections to the same destination.
 
  - Refactor the TCP bind conflict code, shrinking related socket
    structs.
 
  - Refactor TCP SYN-Cookie handling, as a preparation step to
    allow arbitrary SYN-Cookie processing via eBPF.
 
  - Tune optmem_max for 0-copy usage, increasing the default value
    to 128KB and namespecifying it.
 
  - Allow coalescing for cloned skbs coming from page pools, improving
    RX performances with some common configurations.
 
  - Reduce extension header parsing overhead at GRO time.
 
  - Add bridge MDB bulk deletion support, allowing user-space to
    request the deletion of matching entries.
 
  - Reorder nftables struct members, to keep data accessed by the
    datapath first.
 
  - Introduce TC block ports tracking and use. This allows supporting
    multicast-like behavior at the TC layer.
 
  - Remove UAPI support for retired TC qdiscs (dsmark, CBQ and ATM) and
    classifiers (RSVP and tcindex).
 
  - More data-race annotations.
 
  - Extend the diag interface to dump TCP bound-only sockets.
 
  - Conditional notification of events for TC qdisc class and actions.
 
  - Support for WPAN dynamic associations with nearby devices, to form
    a sub-network using a specific PAN ID.
 
  - Implement SMCv2.1 virtual ISM device support.
 
  - Add support for Batman-avd mulicast packet type.
 
 BPF
 ---
 
  - Tons of verifier improvements:
    - BPF register bounds logic and range support along with a large
      test suite
    - log improvements
    - complete precision tracking support for register spills
    - track aligned STACK_ZERO cases as imprecise spilled registers. It
      improves the verifier "instructions processed" metric from single
      digit to 50-60% for some programs
    - support for user's global BPF subprogram arguments with few
      commonly requested annotations for a better developer experience
    - support tracking of BPF_JNE which helps cases when the compiler
      transforms (unsigned) "a > 0" into "if a == 0 goto xxx" and the
      like
    - several fixes
 
  - Add initial TX metadata implementation for AF_XDP with support in
    mlx5 and stmmac drivers. Two types of offloads are supported right
    now, that is, TX timestamp and TX checksum offload.
 
  - Fix kCFI bugs in BPF all forms of indirect calls from BPF into
    kernel and from kernel into BPF work with CFI enabled. This allows
    BPF to work with CONFIG_FINEIBT=y.
 
  - Change BPF verifier logic to validate global subprograms lazily
    instead of unconditionally before the main program, so they can be
    guarded using BPF CO-RE techniques.
 
  - Support uid/gid options when mounting bpffs.
 
  - Add a new kfunc which acquires the associated cgroup of a task
    within a specific cgroup v1 hierarchy where the latter is identified
    by its id.
 
  - Extend verifier to allow bpf_refcount_acquire() of a map value field
    obtained via direct load which is a use-case needed in sched_ext.
 
  - Add BPF link_info support for uprobe multi link along with bpftool
    integration for the latter.
 
  - Support for VLAN tag in XDP hints.
 
  - Remove deprecated bpfilter kernel leftovers given the project
    is developed in user-space (https://github.com/facebook/bpfilter).
 
 Misc
 ----
 
  - Support for parellel TC self-tests execution.
 
  - Increase MPTCP self-tests coverage.
 
  - Updated the bridge documentation, including several so-far
    undocumented features.
 
  - Convert all the net self-tests to run in unique netns, to
    avoid random failures due to conflict and allow concurrent
    runs.
 
  - Add TCP-AO self-tests.
 
  - Add kunit tests for both cfg80211 and mac80211.
 
  - Autogenerate Netlink families documentation from YAML spec.
 
  - Add yml-gen support for fixed headers and recursive nests, the
    tool can now generate user-space code for all genetlink families
    for which we have specs.
 
  - A bunch of additional module descriptions fixes.
 
  - Catch incorrect freeing of pages belonging to a page pool.
 
 Driver API
 ----------
 
  - Rust abstractions for network PHY drivers; do not cover yet the
    full C API, but already allow implementing functional PHY drivers
    in rust.
 
  - Introduce queue and NAPI support in the netdev Netlink interface,
    allowing complete access to the device <> NAPIs <> queues
    relationship.
 
  - Introduce notifications filtering for devlink to allow control
    application scale to thousands of instances.
 
  - Improve PHY validation, requesting rate matching information for
    each ethtool link mode supported by both the PHY and host.
 
  - Add support for ethtool symmetric-xor RSS hash.
 
  - ACPI based Wifi band RFI (WBRF) mitigation feature for the AMD
    platform.
 
  - Expose pin fractional frequency offset value over new DPLL generic
    netlink attribute.
 
  - Convert older drivers to platform remove callback returning void.
 
  - Add support for PHY package MMD read/write.
 
 New hardware / drivers
 ----------------------
 
  - Ethernet:
    - Octeon CN10K devices
    - Broadcom 5760X P7
    - Qualcomm SM8550 SoC
    - Texas Instrument DP83TG720S PHY
 
  - Bluetooth:
    - IMC Networks Bluetooth radio
 
 Removed
 -------
 
  - WiFi:
    - libertas 16-bit PCMCIA support
    - Atmel at76c50x drivers
    - HostAP ISA/PCMCIA style 802.11b driver
    - zd1201 802.11b USB dongles
    - Orinoco ISA/PCMCIA 802.11b driver
    - Aviator/Raytheon driver
    - Planet WL3501 driver
    - RNDIS USB 802.11b driver
 
 Drivers
 -------
 
  - Ethernet high-speed NICs:
    - Intel (100G, ice, idpf):
      - allow one by one port representors creation and removal
      - add temperature and clock information reporting
      - add get/set for ethtool's header split ringparam
      - add again FW logging
      - adds support switchdev hardware packet mirroring
      - iavf: implement symmetric-xor RSS hash
      - igc: add support for concurrent physical and free-running timers
      - i40e: increase the allowable descriptors
    - nVidia/Mellanox:
      - Preparation for Socket-Direct multi-dev netdev. That will allow
        in future releases combining multiple PFs devices attached to
        different NUMA nodes under the same netdev
    - Broadcom (bnxt):
      - TX completion handling improvements
      - add basic ntuple filter support
      - reduce MSIX vectors usage for MQPRIO offload
      - add VXLAN support, USO offload and TX coalesce completion for P7
    - Marvell Octeon EP:
      - xmit-more support
      - add PF-VF mailbox support and use it for FW notifications for VFs
    - Wangxun (ngbe/txgbe):
      - implement ethtool functions to operate pause param, ring param,
        coalesce channel number and msglevel
    - Netronome/Corigine (nfp):
      - add flow-steering support
      - support UDP segmentation offload
 
  - Ethernet NICs embedded, slower, virtual:
    - Xilinx AXI: remove duplicate DMA code adopting the dma engine driver
    - stmmac: add support for HW-accelerated VLAN stripping
    - TI AM654x sw: add mqprio, frame preemption & coalescing
    - gve: add support for non-4k page sizes.
    - virtio-net: support dynamic coalescing moderation
 
  - nVidia/Mellanox Ethernet datacenter switches:
    - allow firmware upgrade without a reboot
    - more flexible support for bridge flooding via the compressed
      FID flooding mode
 
  - Ethernet embedded switches:
    - Microchip:
      - fine-tune flow control and speed configurations in KSZ8xxx
      - KSZ88X3: enable setting rmii reference
    - Renesas:
      - add jumbo frames support
    - Marvell:
      - 88E6xxx: add "eth-mac" and "rmon" stats support
 
  - Ethernet PHYs:
    - aquantia: add firmware load support
    - at803x: refactor the driver to simplify adding support for more
      chip variants
    - NXP C45 TJA11xx: Add MACsec offload support
 
  - Wifi:
    - MediaTek (mt76):
      - NVMEM EEPROM improvements
      - mt7996 Extremely High Throughput (EHT) improvements
      - mt7996 Wireless Ethernet Dispatcher (WED) support
      - mt7996 36-bit DMA support
    - Qualcomm (ath12k):
      - support for a single MSI vector
      - WCN7850: support AP mode
    - Intel (iwlwifi):
      - new debugfs file fw_dbg_clear
      - allow concurrent P2P operation on DFS channels
 
  - Bluetooth:
    - QCA2066: support HFP offload
    - ISO: more broadcast-related improvements
    - NXP: better recovery in case receiver/transmitter get out of sync
 
 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-next-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Paolo Abeni:
 "The most interesting thing is probably the networking structs
  reorganization and a significant amount of changes is around
  self-tests.

  Core & protocols:

   - Analyze and reorganize core networking structs (socks, netdev,
     netns, mibs) to optimize cacheline consumption and set up build
     time warnings to safeguard against future header changes

     This improves TCP performances with many concurrent connections up
     to 40%

   - Add page-pool netlink-based introspection, exposing the memory
     usage and recycling stats. This helps indentify bad PP users and
     possible leaks

   - Refine TCP/DCCP source port selection to no longer favor even
     source port at connect() time when IP_LOCAL_PORT_RANGE is set. This
     lowers the time taken by connect() for hosts having many active
     connections to the same destination

   - Refactor the TCP bind conflict code, shrinking related socket
     structs

   - Refactor TCP SYN-Cookie handling, as a preparation step to allow
     arbitrary SYN-Cookie processing via eBPF

   - Tune optmem_max for 0-copy usage, increasing the default value to
     128KB and namespecifying it

   - Allow coalescing for cloned skbs coming from page pools, improving
     RX performances with some common configurations

   - Reduce extension header parsing overhead at GRO time

   - Add bridge MDB bulk deletion support, allowing user-space to
     request the deletion of matching entries

   - Reorder nftables struct members, to keep data accessed by the
     datapath first

   - Introduce TC block ports tracking and use. This allows supporting
     multicast-like behavior at the TC layer

   - Remove UAPI support for retired TC qdiscs (dsmark, CBQ and ATM) and
     classifiers (RSVP and tcindex)

   - More data-race annotations

   - Extend the diag interface to dump TCP bound-only sockets

   - Conditional notification of events for TC qdisc class and actions

   - Support for WPAN dynamic associations with nearby devices, to form
     a sub-network using a specific PAN ID

   - Implement SMCv2.1 virtual ISM device support

   - Add support for Batman-avd mulicast packet type

  BPF:

   - Tons of verifier improvements:
       - BPF register bounds logic and range support along with a large
         test suite
       - log improvements
       - complete precision tracking support for register spills
       - track aligned STACK_ZERO cases as imprecise spilled registers.
         This improves the verifier "instructions processed" metric from
         single digit to 50-60% for some programs
       - support for user's global BPF subprogram arguments with few
         commonly requested annotations for a better developer
         experience
       - support tracking of BPF_JNE which helps cases when the compiler
         transforms (unsigned) "a > 0" into "if a == 0 goto xxx" and the
         like
       - several fixes

   - Add initial TX metadata implementation for AF_XDP with support in
     mlx5 and stmmac drivers. Two types of offloads are supported right
     now, that is, TX timestamp and TX checksum offload

   - Fix kCFI bugs in BPF all forms of indirect calls from BPF into
     kernel and from kernel into BPF work with CFI enabled. This allows
     BPF to work with CONFIG_FINEIBT=y

   - Change BPF verifier logic to validate global subprograms lazily
     instead of unconditionally before the main program, so they can be
     guarded using BPF CO-RE techniques

   - Support uid/gid options when mounting bpffs

   - Add a new kfunc which acquires the associated cgroup of a task
     within a specific cgroup v1 hierarchy where the latter is
     identified by its id

   - Extend verifier to allow bpf_refcount_acquire() of a map value
     field obtained via direct load which is a use-case needed in
     sched_ext

   - Add BPF link_info support for uprobe multi link along with bpftool
     integration for the latter

   - Support for VLAN tag in XDP hints

   - Remove deprecated bpfilter kernel leftovers given the project is
     developed in user-space (https://github.com/facebook/bpfilter)

  Misc:

   - Support for parellel TC self-tests execution

   - Increase MPTCP self-tests coverage

   - Updated the bridge documentation, including several so-far
     undocumented features

   - Convert all the net self-tests to run in unique netns, to avoid
     random failures due to conflict and allow concurrent runs

   - Add TCP-AO self-tests

   - Add kunit tests for both cfg80211 and mac80211

   - Autogenerate Netlink families documentation from YAML spec

   - Add yml-gen support for fixed headers and recursive nests, the tool
     can now generate user-space code for all genetlink families for
     which we have specs

   - A bunch of additional module descriptions fixes

   - Catch incorrect freeing of pages belonging to a page pool

  Driver API:

   - Rust abstractions for network PHY drivers; do not cover yet the
     full C API, but already allow implementing functional PHY drivers
     in rust

   - Introduce queue and NAPI support in the netdev Netlink interface,
     allowing complete access to the device <> NAPIs <> queues
     relationship

   - Introduce notifications filtering for devlink to allow control
     application scale to thousands of instances

   - Improve PHY validation, requesting rate matching information for
     each ethtool link mode supported by both the PHY and host

   - Add support for ethtool symmetric-xor RSS hash

   - ACPI based Wifi band RFI (WBRF) mitigation feature for the AMD
     platform

   - Expose pin fractional frequency offset value over new DPLL generic
     netlink attribute

   - Convert older drivers to platform remove callback returning void

   - Add support for PHY package MMD read/write

  New hardware / drivers:

   - Ethernet:
       - Octeon CN10K devices
       - Broadcom 5760X P7
       - Qualcomm SM8550 SoC
       - Texas Instrument DP83TG720S PHY

   - Bluetooth:
       - IMC Networks Bluetooth radio

  Removed:

   - WiFi:
       - libertas 16-bit PCMCIA support
       - Atmel at76c50x drivers
       - HostAP ISA/PCMCIA style 802.11b driver
       - zd1201 802.11b USB dongles
       - Orinoco ISA/PCMCIA 802.11b driver
       - Aviator/Raytheon driver
       - Planet WL3501 driver
       - RNDIS USB 802.11b driver

  Driver updates:

   - Ethernet high-speed NICs:
       - Intel (100G, ice, idpf):
          - allow one by one port representors creation and removal
          - add temperature and clock information reporting
          - add get/set for ethtool's header split ringparam
          - add again FW logging
          - adds support switchdev hardware packet mirroring
          - iavf: implement symmetric-xor RSS hash
          - igc: add support for concurrent physical and free-running
            timers
          - i40e: increase the allowable descriptors
       - nVidia/Mellanox:
          - Preparation for Socket-Direct multi-dev netdev. That will
            allow in future releases combining multiple PFs devices
            attached to different NUMA nodes under the same netdev
       - Broadcom (bnxt):
          - TX completion handling improvements
          - add basic ntuple filter support
          - reduce MSIX vectors usage for MQPRIO offload
          - add VXLAN support, USO offload and TX coalesce completion
            for P7
       - Marvell Octeon EP:
          - xmit-more support
          - add PF-VF mailbox support and use it for FW notifications
            for VFs
       - Wangxun (ngbe/txgbe):
          - implement ethtool functions to operate pause param, ring
            param, coalesce channel number and msglevel
       - Netronome/Corigine (nfp):
          - add flow-steering support
          - support UDP segmentation offload

   - Ethernet NICs embedded, slower, virtual:
       - Xilinx AXI: remove duplicate DMA code adopting the dma engine
         driver
       - stmmac: add support for HW-accelerated VLAN stripping
       - TI AM654x sw: add mqprio, frame preemption & coalescing
       - gve: add support for non-4k page sizes.
       - virtio-net: support dynamic coalescing moderation

   - nVidia/Mellanox Ethernet datacenter switches:
       - allow firmware upgrade without a reboot
       - more flexible support for bridge flooding via the compressed
         FID flooding mode

   - Ethernet embedded switches:
       - Microchip:
          - fine-tune flow control and speed configurations in KSZ8xxx
          - KSZ88X3: enable setting rmii reference
       - Renesas:
          - add jumbo frames support
       - Marvell:
          - 88E6xxx: add "eth-mac" and "rmon" stats support

   - Ethernet PHYs:
       - aquantia: add firmware load support
       - at803x: refactor the driver to simplify adding support for more
         chip variants
       - NXP C45 TJA11xx: Add MACsec offload support

   - Wifi:
       - MediaTek (mt76):
          - NVMEM EEPROM improvements
          - mt7996 Extremely High Throughput (EHT) improvements
          - mt7996 Wireless Ethernet Dispatcher (WED) support
          - mt7996 36-bit DMA support
       - Qualcomm (ath12k):
          - support for a single MSI vector
          - WCN7850: support AP mode
       - Intel (iwlwifi):
          - new debugfs file fw_dbg_clear
          - allow concurrent P2P operation on DFS channels

   - Bluetooth:
       - QCA2066: support HFP offload
       - ISO: more broadcast-related improvements
       - NXP: better recovery in case receiver/transmitter get out of sync"

* tag 'net-next-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1714 commits)
  lan78xx: remove redundant statement in lan78xx_get_eee
  lan743x: remove redundant statement in lan743x_ethtool_get_eee
  bnxt_en: Fix RCU locking for ntuple filters in bnxt_rx_flow_steer()
  bnxt_en: Fix RCU locking for ntuple filters in bnxt_srxclsrldel()
  bnxt_en: Remove unneeded variable in bnxt_hwrm_clear_vnic_filter()
  tcp: Revert no longer abort SYN_SENT when receiving some ICMP
  Revert "mlx5 updates 2023-12-20"
  Revert "net: stmmac: Enable Per DMA Channel interrupt"
  ipvlan: Remove usage of the deprecated ida_simple_xx() API
  ipvlan: Fix a typo in a comment
  net/sched: Remove ipt action tests
  net: stmmac: Use interrupt mode INTM=1 for per channel irq
  net: stmmac: Add support for TX/RX channel interrupt
  net: stmmac: Make MSI interrupt routine generic
  dt-bindings: net: snps,dwmac: per channel irq
  net: phy: at803x: make read_status more generic
  net: phy: at803x: add support for cdt cross short test for qca808x
  net: phy: at803x: refactor qca808x cable test get status function
  net: phy: at803x: generalize cdt fault length function
  net: ethernet: cortina: Drop TSO support
  ...
2024-01-11 10:07:29 -08:00
Breno Leitao
7b75782ffd x86/bugs: Rename CONFIG_SLS => CONFIG_MITIGATION_SLS
Step 6/10 of the namespace unification of CPU mitigations related Kconfig options.

Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20231121160740.1249350-7-leitao@debian.org
2024-01-10 10:52:28 +01:00
Breno Leitao
aefb2f2e61 x86/bugs: Rename CONFIG_RETPOLINE => CONFIG_MITIGATION_RETPOLINE
Step 5/10 of the namespace unification of CPU mitigations related Kconfig options.

[ mingo: Converted a few more uses in comments/messages as well. ]

Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ariel Miculas <amiculas@cisco.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20231121160740.1249350-6-leitao@debian.org
2024-01-10 10:52:28 +01:00
Linus Torvalds
b51cc5d028 x86/cleanups changes for v6.8:
- A micro-optimization got misplaced as a cleanup:
     - Micro-optimize the asm code in secondary_startup_64_no_verify()
 
  - Change global variables to local
  - Add missing kernel-doc function parameter descriptions
  - Remove unused parameter from a macro
  - Remove obsolete Kconfig entry
  - Fix comments
  - Fix typos, mostly scripted, manually reviewed
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-cleanups-2024-01-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cleanups from Ingo Molnar:

 - Change global variables to local

 - Add missing kernel-doc function parameter descriptions

 - Remove unused parameter from a macro

 - Remove obsolete Kconfig entry

 - Fix comments

 - Fix typos, mostly scripted, manually reviewed

and a micro-optimization got misplaced as a cleanup:

 - Micro-optimize the asm code in secondary_startup_64_no_verify()

* tag 'x86-cleanups-2024-01-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arch/x86: Fix typos
  x86/head_64: Use TESTB instead of TESTL in secondary_startup_64_no_verify()
  x86/docs: Remove reference to syscall trampoline in PTI
  x86/Kconfig: Remove obsolete config X86_32_SMP
  x86/io: Remove the unused 'bw' parameter from the BUILDIO() macro
  x86/mtrr: Document missing function parameters in kernel-doc
  x86/setup: Make relocated_ramdisk a local variable of relocate_initrd()
2024-01-08 17:23:32 -08:00
Leon Hwang
00bc898880 bpf, x86: Use emit_nops to replace memcpy x86_nops
Move emit_nops() before emit_prologue() and replace
memcpy(prog, x86_nops[5], X86_PATCH_SIZE) with emit_nops(&prog, X86_PATCH_SIZE).

Signed-off-by: Leon Hwang <hffilwlqm@gmail.com>
Link: https://lore.kernel.org/r/20240104142226.87869-2-hffilwlqm@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-01-04 20:22:10 -08:00
Bjorn Helgaas
54aa699e80 arch/x86: Fix typos
Fix typos, most reported by "codespell arch/x86".  Only touches comments,
no code changes.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20240103004011.1758650-1-helgaas@kernel.org
2024-01-03 11:46:22 +01:00
Jakub Kicinski
c49b292d03 netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2023-12-18

This PR is larger than usual and contains changes in various parts
of the kernel.

The main changes are:

1) Fix kCFI bugs in BPF, from Peter Zijlstra.

End result: all forms of indirect calls from BPF into kernel
and from kernel into BPF work with CFI enabled. This allows BPF
to work with CONFIG_FINEIBT=y.

2) Introduce BPF token object, from Andrii Nakryiko.

It adds an ability to delegate a subset of BPF features from privileged
daemon (e.g., systemd) through special mount options for userns-bound
BPF FS to a trusted unprivileged application. The design accommodates
suggestions from Christian Brauner and Paul Moore.

Example:
$ sudo mkdir -p /sys/fs/bpf/token
$ sudo mount -t bpf bpffs /sys/fs/bpf/token \
             -o delegate_cmds=prog_load:MAP_CREATE \
             -o delegate_progs=kprobe \
             -o delegate_attachs=xdp

3) Various verifier improvements and fixes, from Andrii Nakryiko, Andrei Matei.

 - Complete precision tracking support for register spills
 - Fix verification of possibly-zero-sized stack accesses
 - Fix access to uninit stack slots
 - Track aligned STACK_ZERO cases as imprecise spilled registers.
   It improves the verifier "instructions processed" metric from single
   digit to 50-60% for some programs.
 - Fix verifier retval logic

4) Support for VLAN tag in XDP hints, from Larysa Zaremba.

5) Allocate BPF trampoline via bpf_prog_pack mechanism, from Song Liu.

End result: better memory utilization and lower I$ miss for calls to BPF
via BPF trampoline.

6) Fix race between BPF prog accessing inner map and parallel delete,
from Hou Tao.

7) Add bpf_xdp_get_xfrm_state() kfunc, from Daniel Xu.

It allows BPF interact with IPSEC infra. The intent is to support
software RSS (via XDP) for the upcoming ipsec pcpu work.
Experiments on AWS demonstrate single tunnel pcpu ipsec reaching
line rate on 100G ENA nics.

8) Expand bpf_cgrp_storage to support cgroup1 non-attach, from Yafang Shao.

9) BPF file verification via fsverity, from Song Liu.

It allows BPF progs get fsverity digest.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (164 commits)
  bpf: Ensure precise is reset to false in __mark_reg_const_zero()
  selftests/bpf: Add more uprobe multi fail tests
  bpf: Fail uprobe multi link with negative offset
  selftests/bpf: Test the release of map btf
  s390/bpf: Fix indirect trampoline generation
  selftests/bpf: Temporarily disable dummy_struct_ops test on s390
  x86/cfi,bpf: Fix bpf_exception_cb() signature
  bpf: Fix dtor CFI
  cfi: Add CFI_NOSEAL()
  x86/cfi,bpf: Fix bpf_struct_ops CFI
  x86/cfi,bpf: Fix bpf_callback_t CFI
  x86/cfi,bpf: Fix BPF JIT call
  cfi: Flip headers
  selftests/bpf: Add test for abnormal cnt during multi-kprobe attachment
  selftests/bpf: Don't use libbpf_get_error() in kprobe_multi_test
  selftests/bpf: Add test for abnormal cnt during multi-uprobe attachment
  bpf: Limit the number of kprobes when attaching program to multiple kprobes
  bpf: Limit the number of uprobes when attaching program to multiple uprobes
  bpf: xdp: Register generic_kfunc_set with XDP programs
  selftests/bpf: utilize string values for delegate_xxx mount options
  ...
====================

Link: https://lore.kernel.org/r/20231219000520.34178-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-12-18 16:46:08 -08:00
Peter Zijlstra
2cd3e3772e x86/cfi,bpf: Fix bpf_struct_ops CFI
BPF struct_ops uses __arch_prepare_bpf_trampoline() to write
trampolines for indirect function calls. These tramplines much have
matching CFI.

In order to obtain the correct CFI hash for the various methods, add a
matching structure that contains stub functions, the compiler will
generate correct CFI which we can pilfer for the trampolines.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20231215092707.566977112@infradead.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-15 16:25:55 -08:00
Peter Zijlstra
e72d88d18d x86/cfi,bpf: Fix bpf_callback_t CFI
Where the main BPF program is expected to match bpf_func_t,
sub-programs are expected to match bpf_callback_t.

This fixes things like:

tools/testing/selftests/bpf/progs/bloom_filter_bench.c:

           bpf_for_each_map_elem(&array_map, bloom_callback, &data, 0);

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20231215092707.451956710@infradead.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-15 16:25:55 -08:00
Peter Zijlstra
4f9087f166 x86/cfi,bpf: Fix BPF JIT call
The current BPF call convention is __nocfi, except when it calls !JIT things,
then it calls regular C functions.

It so happens that with FineIBT the __nocfi and C calling conventions are
incompatible. Specifically __nocfi will call at func+0, while FineIBT will have
endbr-poison there, which is not a valid indirect target. Causing #CP.

Notably this only triggers on IBT enabled hardware, which is probably why this
hasn't been reported (also, most people will have JIT on anyway).

Implement proper CFI prologues for the BPF JIT codegen and drop __nocfi for
x86.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20231215092707.345270396@infradead.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-15 16:25:55 -08:00
Song Liu
3ba026fca8 x86, bpf: Use bpf_prog_pack for bpf trampoline
There are three major changes here:

1. Add arch_[alloc|free]_bpf_trampoline based on bpf_prog_pack;
2. Let arch_prepare_bpf_trampoline handle ROX input image, this requires
   arch_prepare_bpf_trampoline allocating a temporary RW buffer;
3. Update __arch_prepare_bpf_trampoline() to handle a RW buffer (rw_image)
   and a ROX buffer (image). This part is similar to the image/rw_image
   logic in bpf_int_jit_compile().

Signed-off-by: Song Liu <song@kernel.org>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20231206224054.492250-8-song@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 17:17:21 -08:00
Song Liu
96d1b7c081 bpf: Add arch_bpf_trampoline_size()
This helper will be used to calculate the size of the trampoline before
allocating the memory.

arch_prepare_bpf_trampoline() for arm64 and riscv64 can use
arch_bpf_trampoline_size() to check the trampoline fits in the image.

OTOH, arch_prepare_bpf_trampoline() for s390 has to call the JIT process
twice, so it cannot use arch_bpf_trampoline_size().

Signed-off-by: Song Liu <song@kernel.org>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>  # on s390x
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com> # on riscv
Link: https://lore.kernel.org/r/20231206224054.492250-6-song@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 17:17:20 -08:00
Song Liu
38b8b58ae7 bpf, x86: Adjust arch_prepare_bpf_trampoline return value
x86's implementation of arch_prepare_bpf_trampoline() requires
BPF_INSN_SAFETY buffer space between end of program and image_end. OTOH,
the return value does not include BPF_INSN_SAFETY. This doesn't cause any
real issue at the moment. However, "image" of size retval is not enough for
arch_prepare_bpf_trampoline(). This will cause confusion when we introduce
a new helper arch_bpf_trampoline_size(). To avoid future confusion, adjust
the return value to include BPF_INSN_SAFETY.

Signed-off-by: Song Liu <song@kernel.org>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20231206224054.492250-5-song@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 17:17:20 -08:00
Jiri Olsa
4b7de80160 bpf: Fix prog_array_map_poke_run map poke update
Lee pointed out issue found by syscaller [0] hitting BUG in prog array
map poke update in prog_array_map_poke_run function due to error value
returned from bpf_arch_text_poke function.

There's race window where bpf_arch_text_poke can fail due to missing
bpf program kallsym symbols, which is accounted for with check for
-EINVAL in that BUG_ON call.

The problem is that in such case we won't update the tail call jump
and cause imbalance for the next tail call update check which will
fail with -EBUSY in bpf_arch_text_poke.

I'm hitting following race during the program load:

  CPU 0                             CPU 1

  bpf_prog_load
    bpf_check
      do_misc_fixups
        prog_array_map_poke_track

                                    map_update_elem
                                      bpf_fd_array_map_update_elem
                                        prog_array_map_poke_run

                                          bpf_arch_text_poke returns -EINVAL

    bpf_prog_kallsyms_add

After bpf_arch_text_poke (CPU 1) fails to update the tail call jump, the next
poke update fails on expected jump instruction check in bpf_arch_text_poke
with -EBUSY and triggers the BUG_ON in prog_array_map_poke_run.

Similar race exists on the program unload.

Fixing this by moving the update to bpf_arch_poke_desc_update function which
makes sure we call __bpf_arch_text_poke that skips the bpf address check.

Each architecture has slightly different approach wrt looking up bpf address
in bpf_arch_text_poke, so instead of splitting the function or adding new
'checkip' argument in previous version, it seems best to move the whole
map_poke_run update as arch specific code.

  [0] https://syzkaller.appspot.com/bug?extid=97a4fe20470e9bc30810

Fixes: ebf7d1f508 ("bpf, x64: rework pro/epilogue and tailcall handling in JIT")
Reported-by: syzbot+97a4fe20470e9bc30810@syzkaller.appspotmail.com
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Cc: Lee Jones <lee@kernel.org>
Cc: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20231206083041.1306660-2-jolsa@kernel.org
2023-12-06 22:40:16 +01:00
Kumar Kartikeya Dwivedi
5bfdb4fbf3 bpf: Disable exceptions when CONFIG_UNWINDER_FRAME_POINTER=y
The build with CONFIG_UNWINDER_FRAME_POINTER=y is broken for
current exceptions feature as it assumes ORC unwinder specific fields in
the unwind_state. Disable exceptions when frame_pointer unwinder is
enabled for now.

Fixes: fd5d27b701 ("arch/x86: Implement arch_bpf_stack_walk")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230918155233.297024-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-19 02:07:36 -07:00
Kumar Kartikeya Dwivedi
f18b03faba bpf: Implement BPF exceptions
This patch implements BPF exceptions, and introduces a bpf_throw kfunc
to allow programs to throw exceptions during their execution at runtime.
A bpf_throw invocation is treated as an immediate termination of the
program, returning back to its caller within the kernel, unwinding all
stack frames.

This allows the program to simplify its implementation, by testing for
runtime conditions which the verifier has no visibility into, and assert
that they are true. In case they are not, the program can simply throw
an exception from the other branch.

BPF exceptions are explicitly *NOT* an unlikely slowpath error handling
primitive, and this objective has guided design choices of the
implementation of the them within the kernel (with the bulk of the cost
for unwinding the stack offloaded to the bpf_throw kfunc).

The implementation of this mechanism requires use of add_hidden_subprog
mechanism introduced in the previous patch, which generates a couple of
instructions to move R1 to R0 and exit. The JIT then rewrites the
prologue of this subprog to take the stack pointer and frame pointer as
inputs and reset the stack frame, popping all callee-saved registers
saved by the main subprog. The bpf_throw function then walks the stack
at runtime, and invokes this exception subprog with the stack and frame
pointers as parameters.

Reviewers must take note that currently the main program is made to save
all callee-saved registers on x86_64 during entry into the program. This
is because we must do an equivalent of a lightweight context switch when
unwinding the stack, therefore we need the callee-saved registers of the
caller of the BPF program to be able to return with a sane state.

Note that we have to additionally handle r12, even though it is not used
by the program, because when throwing the exception the program makes an
entry into the kernel which could clobber r12 after saving it on the
stack. To be able to preserve the value we received on program entry, we
push r12 and restore it from the generated subprogram when unwinding the
stack.

For now, bpf_throw invocation fails when lingering resources or locks
exist in that path of the program. In a future followup, bpf_throw will
be extended to perform frame-by-frame unwinding to release lingering
resources for each stack frame, removing this limitation.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16 09:34:21 -07:00
Kumar Kartikeya Dwivedi
fd5d27b701 arch/x86: Implement arch_bpf_stack_walk
The plumbing for offline unwinding when we throw an exception in
programs would require walking the stack, hence introduce a new
arch_bpf_stack_walk function. This is provided when the JIT supports
exceptions, i.e. bpf_jit_supports_exceptions is true. The arch-specific
code is really minimal, hence it should be straightforward to extend
this support to other architectures as well, as it reuses the logic of
arch_stack_walk, but allowing access to unwind_state data.

Once the stack pointer and frame pointer are known for the main subprog
during the unwinding, we know the stack layout and location of any
callee-saved registers which must be restored before we return back to
the kernel. This handling will be added in the subsequent patches.

Note that while we primarily unwind through BPF frames, which are
effectively CONFIG_UNWINDER_FRAME_POINTER, we still need one of this or
CONFIG_UNWINDER_ORC to be able to unwind through the bpf_throw frame
from which we begin walking the stack. We also require both sp and bp
(stack and frame pointers) from the unwind_state structure, which are
only available when one of these two options are enabled.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16 09:34:21 -07:00
Kumar Kartikeya Dwivedi
9af27da631 bpf: Use bpf_is_subprog to check for subprogs
We would like to know whether a bpf_prog corresponds to the main prog or
one of the subprogs. The current JIT implementations simply check this
using the func_idx in bpf_prog->aux->func_idx. When the index is 0, it
belongs to the main program, otherwise it corresponds to some
subprogram.

This will also be necessary to halt exception propagation while walking
the stack when an exception is thrown, so we add a simple helper
function to check this, named bpf_is_subprog, and convert existing JIT
implementations to also make use of it.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16 09:34:20 -07:00
Leon Hwang
2b5dcb31a1 bpf, x64: Fix tailcall infinite loop
From commit ebf7d1f508 ("bpf, x64: rework pro/epilogue and tailcall
handling in JIT"), the tailcall on x64 works better than before.

From commit e411901c0b ("bpf: allow for tailcalls in BPF subprograms
for x64 JIT"), tailcall is able to run in BPF subprograms on x64.

From commit 5b92a28aae ("bpf: Support attaching tracing BPF program
to other BPF programs"), BPF program is able to trace other BPF programs.

How about combining them all together?

1. FENTRY/FEXIT on a BPF subprogram.
2. A tailcall runs in the BPF subprogram.
3. The tailcall calls the subprogram's caller.

As a result, a tailcall infinite loop comes up. And the loop would halt
the machine.

As we know, in tail call context, the tail_call_cnt propagates by stack
and rax register between BPF subprograms. So do in trampolines.

Fixes: ebf7d1f508 ("bpf, x64: rework pro/epilogue and tailcall handling in JIT")
Fixes: e411901c0b ("bpf: allow for tailcalls in BPF subprograms for x64 JIT")
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Leon Hwang <hffilwlqm@gmail.com>
Link: https://lore.kernel.org/r/20230912150442.2009-3-hffilwlqm@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-12 13:06:12 -07:00
Leon Hwang
2bee9770f3 bpf, x64: Comment tail_call_cnt initialisation
Without understanding emit_prologue(), it is really hard to figure out
where does tail_call_cnt come from, even though searching tail_call_cnt
in the whole kernel repo.

By adding these comments, it is a little bit easier to understand
tail_call_cnt initialisation.

Signed-off-by: Leon Hwang <hffilwlqm@gmail.com>
Link: https://lore.kernel.org/r/20230912150442.2009-2-hffilwlqm@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-12 13:06:12 -07:00
Yonghong Song
4cd58e9af8 bpf: Support new 32bit offset jmp instruction
Add interpreter/jit/verifier support for 32bit offset jmp instruction.
If a conditional jmp instruction needs more than 16bit offset,
it can be simulated with a conditional jmp + a 32bit jmp insn.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230728011231.3716103-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-27 18:52:33 -07:00
Yonghong Song
ec0e2da95f bpf: Support new signed div/mod instructions.
Add interpreter/jit support for new signed div/mod insns.
The new signed div/mod instructions are encoded with
unsigned div/mod instructions plus insn->off == 1.
Also add basic verifier support to ensure new insns get
accepted.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230728011219.3714605-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-27 18:52:33 -07:00
Yonghong Song
0845c3db7b bpf: Support new unconditional bswap instruction
The existing 'be' and 'le' insns will do conditional bswap
depends on host endianness. This patch implements
unconditional bswap insns.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230728011213.3712808-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-27 18:52:33 -07:00
Yonghong Song
8100928c88 bpf: Support new sign-extension mov insns
Add interpreter/jit support for new sign-extension mov insns.
The original 'MOV' insn is extended to support reg-to-reg
signed version for both ALU and ALU64 operations. For ALU mode,
the insn->off value of 8 or 16 indicates sign-extension
from 8- or 16-bit value to 32-bit value. For ALU64 mode,
the insn->off value of 8/16/32 indicates sign-extension
from 8-, 16- or 32-bit value to 64-bit value.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230728011202.3712300-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-27 18:52:33 -07:00
Yonghong Song
1f9a1ea821 bpf: Support new sign-extension load insns
Add interpreter/jit support for new sign-extension load insns
which adds a new mode (BPF_MEMSX).
Also add verifier support to recognize these insns and to
do proper verification with new insns. In verifier, besides
to deduce proper bounds for the dst_reg, probed memory access
is also properly handled.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230728011156.3711870-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-27 18:52:33 -07:00
Menglong Dong
492e797fda bpf, x86: initialize the variable "first_off" in save_args()
As Dan Carpenter reported, the variable "first_off" which is passed to
clean_stack_garbage() in save_args() can be uninitialized, which can
cause runtime warnings with KMEMsan. Therefore, init it with 0.

Fixes: 473e3150e3 ("bpf, x86: allow function arguments up to 12 for TRACING")
Cc: Hao Peng <flyingpeng@tencent.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/bpf/09784025-a812-493f-9829-5e26c8691e07@moroto.mountain/
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Link: https://lore.kernel.org/r/20230719110330.2007949-1-imagedong@tencent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-19 09:55:22 -07:00
Menglong Dong
473e3150e3 bpf, x86: allow function arguments up to 12 for TRACING
For now, the BPF program of type BPF_PROG_TYPE_TRACING can only be used
on the kernel functions whose arguments count less than or equal to 6, if
not considering '> 8 bytes' struct argument. This is not friendly at all,
as too many functions have arguments count more than 6.

According to the current kernel version, below is a statistics of the
function arguments count:

argument count | function count
7              | 704
8              | 270
9              | 84
10             | 47
11             | 47
12             | 27
13             | 22
14             | 5
15             | 0
16             | 1

Therefore, let's enhance it by increasing the function arguments count
allowed in arch_prepare_bpf_trampoline(), for now, only x86_64.

For the case that we don't need to call origin function, which means
without BPF_TRAMP_F_CALL_ORIG, we need only copy the function arguments
that stored in the frame of the caller to current frame. The 7th and later
arguments are stored in "$rbp + 0x18", and they will be copied to the
stack area following where register values are saved.

For the case with BPF_TRAMP_F_CALL_ORIG, we need prepare the arguments
in stack before call origin function, which means we need alloc extra
"8 * (arg_count - 6)" memory in the top of the stack. Note, there should
not be any data be pushed to the stack before calling the origin function.
So 'rbx' value will be stored on a stack position higher than where stack
arguments are stored for BPF_TRAMP_F_CALL_ORIG.

According to the research of Yonghong, struct members should be all in
register or all on the stack. Meanwhile, the compiler will pass the
argument on regs if the remaining regs can hold the argument. Therefore,
we need save the arguments in order. Otherwise, disorder of the args can
happen. For example:

  struct foo_struct {
      long a;
      int b;
  };
  int foo(char, char, char, char, char, struct foo_struct,
          char);

the arg1-5,arg7 will be passed by regs, and arg6 will by stack. Therefore,
we should save/restore the arguments in the same order with the
declaration of foo(). And the args used as ctx in stack will be like this:

  reg_arg6   -- copy from regs
  stack_arg2 -- copy from stack
  stack_arg1
  reg_arg5   -- copy from regs
  reg_arg4
  reg_arg3
  reg_arg2
  reg_arg1

We use EMIT3_off32() or EMIT4() for "lea" and "sub". The range of the
imm in "lea" and "sub" is [-128, 127] if EMIT4() is used. Therefore,
we use EMIT3_off32() instead if the imm out of the range.

It works well for the FENTRY/FEXIT/MODIFY_RETURN.

Signed-off-by: Menglong Dong <imagedong@tencent.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230713040738.1789742-3-imagedong@tencent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-13 16:04:56 -07:00
Menglong Dong
02a6dfa8ff bpf, x86: save/restore regs with BPF_DW size
As we already reserve 8 byte in the stack for each reg, it is ok to
store/restore the regs in BPF_DW size. This will make the code in
save_regs()/restore_regs() simpler.

Signed-off-by: Menglong Dong <imagedong@tencent.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230713040738.1789742-2-imagedong@tencent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-13 16:04:56 -07:00