load_module() creates W+X mappings via __vmalloc_node_range() (from
layout_and_allocate()->move_module()->module_alloc()) by using
PAGE_KERNEL_EXEC. These mappings are later cleaned up via
"call_rcu_sched(&freeinit->rcu, do_free_init)" from do_init_module().
This is a problem because call_rcu_sched() queues work, which can be run
after debug_checkwx() is run, resulting in a race condition. If hit,
the race results in a nasty splat about insecure W+X mappings, which
results in a poor user experience as these are not the mappings that
debug_checkwx() is intended to catch.
This issue is observed on multiple arm64 platforms, and has been
artificially triggered on an x86 platform.
Address the race by flushing the queued work before running the
arch-defined mark_rodata_ro() which then calls debug_checkwx().
Link: http://lkml.kernel.org/r/1525103946-29526-1-git-send-email-jhugo@codeaurora.org
Fixes: e1a58320a3 ("x86/mm: Warn on W^X mappings")
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reported-by: Timur Tabi <timur@codeaurora.org>
Reported-by: Jan Glauber <jan.glauber@caviumnetworks.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
So "struct uts_namespace" can enjoy fine-grained SLAB debugging and
usercopy protection.
I'd prefer shorter name "utsns" but there is "user_namespace" already.
Link: http://lkml.kernel.org/r/20180228215158.GA23146@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Tom Zanussi's extended histogram work
This adds the synthetic events to have histograms from multiple event data
Adds triggers "onmatch" and "onmax" to call the synthetic events
Several updates to the histogram code from this
- Allow way to nest ring buffer calls in the same context
- Allow absolute time stamps in ring buffer
- Rewrite of filter code parsing based on Al Viro's suggestions
- Setting of trace_clock to global if TSC is unstable (on boot)
- Better OOM handling when allocating large ring buffers
- Added initcall tracepoints (consolidated initcall_debug code with them)
And other various fixes and clean ups
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Merge tag 'trace-v4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"New features:
- Tom Zanussi's extended histogram work.
This adds the synthetic events to have histograms from multiple
event data Adds triggers "onmatch" and "onmax" to call the
synthetic events Several updates to the histogram code from this
- Allow way to nest ring buffer calls in the same context
- Allow absolute time stamps in ring buffer
- Rewrite of filter code parsing based on Al Viro's suggestions
- Setting of trace_clock to global if TSC is unstable (on boot)
- Better OOM handling when allocating large ring buffers
- Added initcall tracepoints (consolidated initcall_debug code with
them)
And other various fixes and clean ups"
* tag 'trace-v4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (68 commits)
init: Have initcall_debug still work without CONFIG_TRACEPOINTS
init, tracing: Have printk come through the trace events for initcall_debug
init, tracing: instrument security and console initcall trace events
init, tracing: Add initcall trace events
tracing: Add rcu dereference annotation for test func that touches filter->prog
tracing: Add rcu dereference annotation for filter->prog
tracing: Fixup logic inversion on setting trace_global_clock defaults
tracing: Hide global trace clock from lockdep
ring-buffer: Add set/clear_current_oom_origin() during allocations
ring-buffer: Check if memory is available before allocation
lockdep: Add print_irqtrace_events() to __warn
vsprintf: Do not preprocess non-dereferenced pointers for bprintf (%px and %pK)
tracing: Uninitialized variable in create_tracing_map_fields()
tracing: Make sure variable string fields are NULL-terminated
tracing: Add action comparisons when testing matching hist triggers
tracing: Don't add flag strings when displaying variable references
tracing: Fix display of hist trigger expressions containing timestamps
ftrace: Drop a VLA in module_exists()
tracing: Mention trace_clock=global when warning about unstable clocks
tracing: Default to using trace_global_clock if sched_clock is unstable
...
Add macros around the initcall_debug tracepoint code to have the code to
default back to the old method if CONFIG_TRACEPOINTS is not enabled.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
With trace events set before and after the initcall function calls, instead
of having a separate routine for printing out the initcalls when
initcall_debug is specified on the kernel command line, have the code
register a callback to the tracepoints where the initcall trace events are.
This removes the need for having a separate function to do the initcalls as
the tracepoint callbacks can handle the printk. It also includes other
initcalls that are not called by the do_one_initcall() which includes
console and security initcalls.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Being able to trace the start and stop of initcalls is useful to see where
the timings are an issue. There is already an "initcall_debug" parameter,
but that can cause a large overhead itself, as the printing of the
information may take longer than the initcall functions.
Adding in a start and finish trace event around the initcall functions, as
well as a trace event that records the level of the initcalls, one can get a
much finer measurement of the times and interactions of the initcalls
themselves, as trace events are much lighter than printk()s.
Suggested-by: Abderrahmane Benbachir <abderrahmane.benbachir@polymtl.ca>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Pull removal of in-kernel calls to syscalls from Dominik Brodowski:
"System calls are interaction points between userspace and the kernel.
Therefore, system call functions such as sys_xyzzy() or
compat_sys_xyzzy() should only be called from userspace via the
syscall table, but not from elsewhere in the kernel.
At least on 64-bit x86, it will likely be a hard requirement from
v4.17 onwards to not call system call functions in the kernel: It is
better to use use a different calling convention for system calls
there, where struct pt_regs is decoded on-the-fly in a syscall wrapper
which then hands processing over to the actual syscall function. This
means that only those parameters which are actually needed for a
specific syscall are passed on during syscall entry, instead of
filling in six CPU registers with random user space content all the
time (which may cause serious trouble down the call chain). Those
x86-specific patches will be pushed through the x86 tree in the near
future.
Moreover, rules on how data may be accessed may differ between kernel
data and user data. This is another reason why calling sys_xyzzy() is
generally a bad idea, and -- at most -- acceptable in arch-specific
code.
This patchset removes all in-kernel calls to syscall functions in the
kernel with the exception of arch/. On top of this, it cleans up the
three places where many syscalls are referenced or prototyped, namely
kernel/sys_ni.c, include/linux/syscalls.h and include/linux/compat.h"
* 'syscalls-next' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux: (109 commits)
bpf: whitelist all syscalls for error injection
kernel/sys_ni: remove {sys_,sys_compat} from cond_syscall definitions
kernel/sys_ni: sort cond_syscall() entries
syscalls/x86: auto-create compat_sys_*() prototypes
syscalls: sort syscall prototypes in include/linux/compat.h
net: remove compat_sys_*() prototypes from net/compat.h
syscalls: sort syscall prototypes in include/linux/syscalls.h
kexec: move sys_kexec_load() prototype to syscalls.h
x86/sigreturn: use SYSCALL_DEFINE0
x86: fix sys_sigreturn() return type to be long, not unsigned long
x86/ioport: add ksys_ioperm() helper; remove in-kernel calls to sys_ioperm()
mm: add ksys_readahead() helper; remove in-kernel calls to sys_readahead()
mm: add ksys_mmap_pgoff() helper; remove in-kernel calls to sys_mmap_pgoff()
mm: add ksys_fadvise64_64() helper; remove in-kernel call to sys_fadvise64_64()
fs: add ksys_fallocate() wrapper; remove in-kernel calls to sys_fallocate()
fs: add ksys_p{read,write}64() helpers; remove in-kernel calls to syscalls
fs: add ksys_truncate() wrapper; remove in-kernel calls to sys_truncate()
fs: add ksys_sync_file_range helper(); remove in-kernel calls to syscall
kernel: add ksys_setsid() helper; remove in-kernel call to sys_setsid()
kernel: add ksys_unshare() helper; remove in-kernel calls to sys_unshare()
...
Using this wrapper allows us to avoid the in-kernel calls to the
sys_open() syscall. The ksys_ prefix denotes that this function is meant
as a drop-in replacement for the syscall. In particular, it uses the
same calling convention as sys_open().
This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Using the fs-internal do_faccessat() helper allows us to get rid of
fs-internal calls to the sys_faccessat() syscall.
Introducing the ksys_access() wrapper allows us to avoid the in-kernel
calls to the sys_access() syscall. The ksys_ prefix denotes that this
function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as sys_access().
This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Using ksys_dup() and ksys_dup3() as helper functions allows us to
avoid the in-kernel calls to the sys_dup() and sys_dup3() syscalls.
The ksys_ prefix denotes that these functions are meant as a drop-in
replacement for the syscalls. In particular, they use the same
calling convention as sys_dup{,3}().
In the near future, the fs-external callers of ksys_dup{,3}() should be
converted to call do_dup2() directly. Then, ksys_dup{,3}() can be moved
within sys_dup{,3}() again.
This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
The early_initcall() functions get assigned to __initcall_start[]. These are
called by do_pre_smp_initcalls(). The initcall_levels[] array starts with
__initcall0_start[], and initcall_levels[] are to match the
initcall_level_names[] array. The first name in that array is "early", but
that is not correct. As pure_initcall() functions get assigned to
__initcall0_start[] array.
Change the first name in initcall_level_names[] array to "pure".
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
With the following commit:
3335224470 ("jump_label: Explicitly disable jump labels in __init code")
... we explicitly disabled jump labels in __init code, so they could be
detected and not warned about in the following commit:
dc1dd184c2 ("jump_label: Warn on failed jump_label patching attempt")
In-kernel __exit code has the same issue. It's never used, so it's
freed along with the rest of initmem. But jump label entries in __exit
code aren't explicitly disabled, so we get the following warning when
enabling pr_debug() in __exit code:
can't patch jump_label at dmi_sysfs_exit+0x0/0x2d
WARNING: CPU: 0 PID: 22572 at kernel/jump_label.c:376 __jump_label_update+0x9d/0xb0
Fix the warning by disabling all jump labels in initmem (which includes
both __init and __exit code).
Reported-and-tested-by: Li Wang <liwang@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: dc1dd184c2 ("jump_label: Warn on failed jump_label patching attempt")
Link: http://lkml.kernel.org/r/7121e6e595374f06616c505b6e690e275c0054d1.1521483452.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
After initmem has been freed, any jump labels in __init code are
prevented from being written to by the kernel_text_address() check in
__jump_label_update(). However, this check is quite broad. If
kernel_text_address() were to return false for any other reason, the
jump label write would fail silently with no warning.
For jump labels in module init code, entry->code is set to zero to
indicate that the entry is disabled. Do the same thing for core kernel
init code. This makes the behavior more consistent, and will also make
it more straightforward to detect non-init jump label write failures in
the next patch.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/c52825c73f3a174e8398b6898284ec20d4deb126.1519051220.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 page table isolation updates from Thomas Gleixner:
"This is the final set of enabling page table isolation on x86:
- Infrastructure patches for handling the extra page tables.
- Patches which map the various bits and pieces which are required to
get in and out of user space into the user space visible page
tables.
- The required changes to have CR3 switching in the entry/exit code.
- Optimizations for the CR3 switching along with documentation how
the ASID/PCID mechanism works.
- Updates to dump pagetables to cover the user space page tables for
W+X scans and extra debugfs files to analyze both the kernel and
the user space visible page tables
The whole functionality is compile time controlled via a config switch
and can be turned on/off on the command line as well"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
x86/ldt: Make the LDT mapping RO
x86/mm/dump_pagetables: Allow dumping current pagetables
x86/mm/dump_pagetables: Check user space page table for WX pages
x86/mm/dump_pagetables: Add page table directory to the debugfs VFS hierarchy
x86/mm/pti: Add Kconfig
x86/dumpstack: Indicate in Oops whether PTI is configured and enabled
x86/mm: Clarify the whole ASID/kernel PCID/user PCID naming
x86/mm: Use INVPCID for __native_flush_tlb_single()
x86/mm: Optimize RESTORE_CR3
x86/mm: Use/Fix PCID to optimize user/kernel switches
x86/mm: Abstract switching CR3
x86/mm: Allow flushing for future ASID switches
x86/pti: Map the vsyscall page if needed
x86/pti: Put the LDT in its own PGD if PTI is on
x86/mm/64: Make a full PGD-entry size hole in the memory map
x86/events/intel/ds: Map debug buffers in cpu_entry_area
x86/cpu_entry_area: Add debugstore entries to cpu_entry_area
x86/mm/pti: Map ESPFIX into user space
x86/mm/pti: Share entry text PMD
x86/entry: Align entry text section to PMD boundary
...
Pull x86 PTI preparatory patches from Thomas Gleixner:
"Todays Advent calendar window contains twentyfour easy to digest
patches. The original plan was to have twenty three matching the date,
but a late fixup made that moot.
- Move the cpu_entry_area mapping out of the fixmap into a separate
address space. That's necessary because the fixmap becomes too big
with NRCPUS=8192 and this caused already subtle and hard to
diagnose failures.
The top most patch is fresh from today and cures a brain slip of
that tall grumpy german greybeard, who ignored the intricacies of
32bit wraparounds.
- Limit the number of CPUs on 32bit to 64. That's insane big already,
but at least it's small enough to prevent address space issues with
the cpu_entry_area map, which have been observed and debugged with
the fixmap code
- A few TLB flush fixes in various places plus documentation which of
the TLB functions should be used for what.
- Rename the SYSENTER stack to CPU_ENTRY_AREA stack as it is used for
more than sysenter now and keeping the name makes backtraces
confusing.
- Prevent LDT inheritance on exec() by moving it to arch_dup_mmap(),
which is only invoked on fork().
- Make vysycall more robust.
- A few fixes and cleanups of the debug_pagetables code. Check
PAGE_PRESENT instead of checking the PTE for 0 and a cleanup of the
C89 initialization of the address hint array which already was out
of sync with the index enums.
- Move the ESPFIX init to a different place to prepare for PTI.
- Several code moves with no functional change to make PTI
integration simpler and header files less convoluted.
- Documentation fixes and clarifications"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
x86/cpu_entry_area: Prevent wraparound in setup_cpu_entry_area_ptes() on 32bit
init: Invoke init_espfix_bsp() from mm_init()
x86/cpu_entry_area: Move it out of the fixmap
x86/cpu_entry_area: Move it to a separate unit
x86/mm: Create asm/invpcid.h
x86/mm: Put MMU to hardware ASID translation in one place
x86/mm: Remove hard-coded ASID limit checks
x86/mm: Move the CR3 construction functions to tlbflush.h
x86/mm: Add comments to clarify which TLB-flush functions are supposed to flush what
x86/mm: Remove superfluous barriers
x86/mm: Use __flush_tlb_one() for kernel memory
x86/microcode: Dont abuse the TLB-flush interface
x86/uv: Use the right TLB-flush API
x86/entry: Rename SYSENTER_stack to CPU_ENTRY_AREA_entry_stack
x86/doc: Remove obvious weirdnesses from the x86 MM layout documentation
x86/mm/64: Improve the memory map documentation
x86/ldt: Prevent LDT inheritance on exec
x86/ldt: Rework locking
arch, mm: Allow arch_dup_mmap() to fail
x86/vsyscall/64: Warn and fail vsyscall emulation in NATIVE mode
...
init_espfix_bsp() needs to be invoked before the page table isolation
initialization. Move it into mm_init() which is the place where pti_init()
will be added.
While at it get rid of the #ifdeffery and provide proper stub functions.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This is needed in order to allow the unbound workqueue to take
housekeeping cpus into accounty
Signed-off-by: Tal Shorer <tal.shorer@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
pidhash is no longer required as all the information can be looked up
from idr tree. nr_hashed represented the number of pids that had been
hashed. Since, nr_hashed and PIDNS_HASH_ADDING are no longer relevant,
it has been renamed to pid_allocated and PIDNS_ADDING respectively.
[gs051095@gmail.com: v6]
Link: http://lkml.kernel.org/r/1507760379-21662-3-git-send-email-gs051095@gmail.com
Link: http://lkml.kernel.org/r/1507583624-22146-3-git-send-email-gs051095@gmail.com
Signed-off-by: Gargi Sharma <gs051095@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Tested-by: Tony Luck <tony.luck@intel.com> [ia64]
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "Replacing PID bitmap implementation with IDR API", v4.
This series replaces kernel bitmap implementation of PID allocation with
IDR API. These patches are written to simplify the kernel by replacing
custom code with calls to generic code.
The following are the stats for pid and pid_namespace object files
before and after the replacement. There is a noteworthy change between
the IDR and bitmap implementation.
Before
text data bss dec hex filename
8447 3894 64 12405 3075 kernel/pid.o
After
text data bss dec hex filename
3397 304 0 3701 e75 kernel/pid.o
Before
text data bss dec hex filename
5692 1842 192 7726 1e2e kernel/pid_namespace.o
After
text data bss dec hex filename
2854 216 16 3086 c0e kernel/pid_namespace.o
The following are the stats for ps, pstree and calling readdir on /proc
for 10,000 processes.
ps:
With IDR API With bitmap
real 0m1.479s 0m2.319s
user 0m0.070s 0m0.060s
sys 0m0.289s 0m0.516s
pstree:
With IDR API With bitmap
real 0m1.024s 0m1.794s
user 0m0.348s 0m0.612s
sys 0m0.184s 0m0.264s
proc:
With IDR API With bitmap
real 0m0.059s 0m0.074s
user 0m0.000s 0m0.004s
sys 0m0.016s 0m0.016s
This patch (of 2):
Replace the current bitmap implementation for Process ID allocation.
Functions that are no longer required, for example, free_pidmap(),
alloc_pidmap(), etc. are removed. The rest of the functions are
modified to use the IDR API. The change was made to make the PID
allocation less complex by replacing custom code with calls to generic
API.
[gs051095@gmail.com: v6]
Link: http://lkml.kernel.org/r/1507760379-21662-2-git-send-email-gs051095@gmail.com
[avagin@openvz.org: restore the old behaviour of the ns_last_pid sysctl]
Link: http://lkml.kernel.org/r/20171106183144.16368-1-avagin@openvz.org
Link: http://lkml.kernel.org/r/1507583624-22146-2-git-send-email-gs051095@gmail.com
Signed-off-by: Gargi Sharma <gs051095@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "kmemcheck: kill kmemcheck", v2.
As discussed at LSF/MM, kill kmemcheck.
KASan is a replacement that is able to work without the limitation of
kmemcheck (single CPU, slow). KASan is already upstream.
We are also not aware of any users of kmemcheck (or users who don't
consider KASan as a suitable replacement).
The only objection was that since KASAN wasn't supported by all GCC
versions provided by distros at that time we should hold off for 2
years, and try again.
Now that 2 years have passed, and all distros provide gcc that supports
KASAN, kill kmemcheck again for the very same reasons.
This patch (of 4):
Remove kmemcheck annotations, and calls to kmemcheck from the kernel.
[alexander.levin@verizon.com: correctly remove kmemcheck call from dma_map_sg_attrs]
Link: http://lkml.kernel.org/r/20171012192151.26531-1-alexander.levin@verizon.com
Link: http://lkml.kernel.org/r/20171007030159.22241-2-alexander.levin@verizon.com
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Hansen <devtimhansen@gmail.com>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 APIC updates from Thomas Gleixner:
"This update provides a major overhaul of the APIC initialization and
vector allocation code:
- Unification of the APIC and interrupt mode setup which was
scattered all over the place and was hard to follow. This also
distangles the timer setup from the APIC initialization which
brings a clear separation of functionality.
Great detective work from Dou Lyiang!
- Refactoring of the x86 vector allocation mechanism. The existing
code was based on nested loops and rather convoluted APIC callbacks
which had a horrible worst case behaviour and tried to serve all
different use cases in one go. This led to quite odd hacks when
supporting the new managed interupt facility for multiqueue devices
and made it more or less impossible to deal with the vector space
exhaustion which was a major roadblock for server hibernation.
Aside of that the code dealing with cpu hotplug and the system
vectors was disconnected from the actual vector management and
allocation code, which made it hard to follow and maintain.
Utilizing the new bitmap matrix allocator core mechanism, the new
allocator and management code consolidates the handling of system
vectors, legacy vectors, cpu hotplug mechanisms and the actual
allocation which needs to be aware of system and legacy vectors and
hotplug constraints into a single consistent entity.
This has one visible change: The support for multi CPU targets of
interrupts, which is only available on a certain subset of
CPUs/APIC variants has been removed in favour of single interrupt
targets. A proper analysis of the multi CPU target feature revealed
that there is no real advantage as the vast majority of interrupts
end up on the CPU with the lowest APIC id in the set of target CPUs
anyway. That change was agreed on by the relevant folks and allowed
to simplify the implementation significantly and to replace rather
fragile constructs like the vector cleanup IPI with straight
forward and solid code.
Furthermore this allowed to cleanly separate the allocation details
for legacy, normal and managed interrupts:
* Legacy interrupts are not longer wasting 16 vectors
unconditionally
* Managed interrupts have now a guaranteed vector reservation, but
the actual vector assignment happens when the interrupt is
requested. It's guaranteed not to fail.
* Normal interrupts no longer allocate vectors unconditionally
when the interrupt is set up (IO/APIC init or MSI(X) enable).
The mechanism has been switched to a best effort reservation
mode. The actual allocation happens when the interrupt is
requested. Contrary to managed interrupts the request can fail
due to vector space exhaustion, but drivers must handle a fail
of request_irq() anyway. When the interrupt is freed, the vector
is handed back as well.
This solves a long standing problem with large unconditional
vector allocations for a certain class of enterprise devices
which prevented server hibernation due to vector space
exhaustion when the unused allocated vectors had to be migrated
to CPU0 while unplugging all non boot CPUs.
The code has been equipped with trace points and detailed debugfs
information to aid analysis of the vector space"
* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
x86/vector/msi: Select CONFIG_GENERIC_IRQ_RESERVATION_MODE
PCI/MSI: Set MSI_FLAG_MUST_REACTIVATE in core code
genirq: Add config option for reservation mode
x86/vector: Use correct per cpu variable in free_moved_vector()
x86/apic/vector: Ignore set_affinity call for inactive interrupts
x86/apic: Fix spelling mistake: "symmectic" -> "symmetric"
x86/apic: Use dead_cpu instead of current CPU when cleaning up
ACPI/init: Invoke early ACPI initialization earlier
x86/vector: Respect affinity mask in irq descriptor
x86/irq: Simplify hotplug vector accounting
x86/vector: Switch IOAPIC to global reservation mode
x86/vector/msi: Switch to global reservation mode
x86/vector: Handle managed interrupts proper
x86/io_apic: Reevaluate vector configuration on activate()
iommu/amd: Reevaluate vector configuration on activate()
iommu/vt-d: Reevaluate vector configuration on activate()
x86/apic/msi: Force reactivation of interrupts at startup time
x86/vector: Untangle internal state from irq_cfg
x86/vector: Compile SMP only code conditionally
x86/apic: Remove unused callbacks
...
The housekeeping code is currently tied to the NOHZ code. As we are
planning to make housekeeping independent from it, start with moving
the relevant code to its own file.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Link: http://lkml.kernel.org/r/1509072159-31808-2-git-send-email-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
acpi_early_init() unmaps the temporary ACPI Table mappings which are used
in the early startup code and prepares for permanent table mappings.
Before the consolidation of the x86 APIC setup code the invocation of
acpi_early_init() happened before the interrupt remapping unit was
initialized. With the rework the remapping unit initialization moved in
front of acpi_early_init() which causes an ACPI warning when the ACPI root
tables get reallocated afterwards.
Invoke acpi_early_init() before late_time_init() which is before the access
to the DMAR tables happens.
Fixes: 935356cecd ("x86/apic: Initialize interrupt mode after timer init")
Reported-by: Xiaolong Ye <xiaolong.ye@intel.com>
Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-ia64@vger.kernel.org
Cc: bhe@redhat.com
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-acpi@vger.kernel.org
Cc: bp@alien8.de
Cc: Lv" <lv.zheng@intel.com>
Cc: yinghai@kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lkml.kernel.org/r/1505294274-441-1-git-send-email-douly.fnst@cn.fujitsu.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Feed the boot command-line as to the /dev/random entropy pool
Existing Android bootloaders usually pass data which may not be known by
an external attacker on the kernel command-line. It may also be the
case on other embedded systems. Sample command-line from a Google Pixel
running CopperheadOS....
console=ttyHSL0,115200,n8 androidboot.console=ttyHSL0
androidboot.hardware=sailfish user_debug=31 ehci-hcd.park=3
lpm_levels.sleep_disabled=1 cma=32M@0-0xffffffff buildvariant=user
veritykeyid=id:dfcb9db0089e5b3b4090a592415c28e1cb4545ab
androidboot.bootdevice=624000.ufshc androidboot.verifiedbootstate=yellow
androidboot.veritymode=enforcing androidboot.keymaster=1
androidboot.serialno=FA6CE0305299 androidboot.baseband=msm
mdss_mdp.panel=1:dsi:0:qcom,mdss_dsi_samsung_ea8064tg_1080p_cmd:1:none:cfg:single_dsi
androidboot.slot_suffix=_b fpsimd.fpsimd_settings=0
app_setting.use_app_setting=0 kernelflag=0x00000000 debugflag=0x00000000
androidboot.hardware.revision=PVT radioflag=0x00000000
radioflagex1=0x00000000 radioflagex2=0x00000000 cpumask=0x00000000
androidboot.hardware.ddr=4096MB,Hynix,LPDDR4 androidboot.ddrinfo=00000006
androidboot.ddrsize=4GB androidboot.hardware.color=GRA00
androidboot.hardware.ufs=32GB,Samsung androidboot.msm.hw_ver_id=268824801
androidboot.qf.st=2 androidboot.cid=11111111 androidboot.mid=G-2PW4100
androidboot.bootloader=8996-012001-1704121145
androidboot.oem_unlock_support=1 androidboot.fp_src=1
androidboot.htc.hrdump=detected androidboot.ramdump.opt=mem@2g:2g,mem@4g:2g
androidboot.bootreason=reboot androidboot.ramdump_enable=0 ro
root=/dev/dm-0 dm="system none ro,0 1 android-verity /dev/sda34"
rootwait skip_initramfs init=/init androidboot.wificountrycode=US
androidboot.boottime=1BLL:85,1BLE:669,2BLL:0,2BLE:1777,SW:6,KL:8136
Among other things, it contains a value unique to the device
(androidboot.serialno=FA6CE0305299), unique to the OS builds for the
device variant (veritykeyid=id:dfcb9db0089e5b3b4090a592415c28e1cb4545ab)
and timings from the bootloader stages in milliseconds
(androidboot.boottime=1BLL:85,1BLE:669,2BLL:0,2BLE:1777,SW:6,KL:8136).
[tytso@mit.edu: changelog tweak]
[labbott@redhat.com: line-wrapped command line]
Link: http://lkml.kernel.org/r/20170816231458.2299-3-labbott@redhat.com
Signed-off-by: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Nick Kralevich <nnk@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "Command line randomness", v3.
A series to add the kernel command line as a source of randomness.
This patch (of 2):
Stack canary intialization involves getting a random number. Getting this
random number may involve accessing caches or other architectural specific
features which are not available until after the architecture is setup.
Move the stack canary initialization later to accommodate this.
Link: http://lkml.kernel.org/r/20170816231458.2299-2-labbott@redhat.com
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: Nick Kralevich <nnk@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull percpu updates from Tejun Heo:
"A lot of changes for percpu this time around. percpu inherited the
same area allocator from the original pre-virtual-address-mapped
implementation. This was from the time when percpu allocator wasn't
used all that much and the implementation was focused on simplicity,
with the unfortunate computational complexity of O(number of areas
allocated from the chunk) per alloc / free.
With the increase in percpu usage, we're hitting cases where the lack
of scalability is hurting. The most prominent one right now is bpf
perpcu map creation / destruction which may allocate and free a lot of
entries consecutively and it's likely that the problem will become
more prominent in the future.
To address the issue, Dennis replaced the area allocator with hinted
bitmap allocator which is more consistent. While the new allocator
does perform a bit worse in some cases, it outperforms the old
allocator way more than an order of magnitude in other more common
scenarios while staying mostly flat in CPU overhead and completely
flat in memory consumption"
* 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (27 commits)
percpu: update header to contain bitmap allocator explanation.
percpu: update pcpu_find_block_fit to use an iterator
percpu: use metadata blocks to update the chunk contig hint
percpu: update free path to take advantage of contig hints
percpu: update alloc path to only scan if contig hints are broken
percpu: keep track of the best offset for contig hints
percpu: skip chunks if the alloc does not fit in the contig hint
percpu: add first_bit to keep track of the first free in the bitmap
percpu: introduce bitmap metadata blocks
percpu: replace area map allocator with bitmap
percpu: generalize bitmap (un)populated iterators
percpu: increase minimum percpu allocation size and align first regions
percpu: introduce nr_empty_pop_pages to help empty page accounting
percpu: change the number of pages marked in the first_chunk pop bitmap
percpu: combine percpu address checks
percpu: modify base_addr to be region specific
percpu: setup_first_chunk rename schunk/dchunk to chunk
percpu: end chunk area maps page aligned for the populated bitmap
percpu: unify allocation of schunk and dchunk
percpu: setup_first_chunk remove dyn_size and consolidate logic
...
build_all_zonelists gets a zone parameter to initialize zone's pagesets.
There is only a single user which gives a non-NULL zone parameter and
that one doesn't really need the rest of the build_all_zonelists (see
commit 6dcd73d701 ("memory-hotplug: allocate zone's pcp before
onlining pages")).
Therefore remove setup_zone_pageset from build_all_zonelists and call it
from its only user directly. This will also remove a pointless zonlists
rebuilding which is always good.
Link: http://lkml.kernel.org/r/20170721143915.14161-5-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 mm changes from Ingo Molnar:
"PCID support, 5-level paging support, Secure Memory Encryption support
The main changes in this cycle are support for three new, complex
hardware features of x86 CPUs:
- Add 5-level paging support, which is a new hardware feature on
upcoming Intel CPUs allowing up to 128 PB of virtual address space
and 4 PB of physical RAM space - a 512-fold increase over the old
limits. (Supercomputers of the future forecasting hurricanes on an
ever warming planet can certainly make good use of more RAM.)
Many of the necessary changes went upstream in previous cycles,
v4.14 is the first kernel that can enable 5-level paging.
This feature is activated via CONFIG_X86_5LEVEL=y - disabled by
default.
(By Kirill A. Shutemov)
- Add 'encrypted memory' support, which is a new hardware feature on
upcoming AMD CPUs ('Secure Memory Encryption', SME) allowing system
RAM to be encrypted and decrypted (mostly) transparently by the
CPU, with a little help from the kernel to transition to/from
encrypted RAM. Such RAM should be more secure against various
attacks like RAM access via the memory bus and should make the
radio signature of memory bus traffic harder to intercept (and
decrypt) as well.
This feature is activated via CONFIG_AMD_MEM_ENCRYPT=y - disabled
by default.
(By Tom Lendacky)
- Enable PCID optimized TLB flushing on newer Intel CPUs: PCID is a
hardware feature that attaches an address space tag to TLB entries
and thus allows to skip TLB flushing in many cases, even if we
switch mm's.
(By Andy Lutomirski)
All three of these features were in the works for a long time, and
it's coincidence of the three independent development paths that they
are all enabled in v4.14 at once"
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (65 commits)
x86/mm: Enable RCU based page table freeing (CONFIG_HAVE_RCU_TABLE_FREE=y)
x86/mm: Use pr_cont() in dump_pagetable()
x86/mm: Fix SME encryption stack ptr handling
kvm/x86: Avoid clearing the C-bit in rsvd_bits()
x86/CPU: Align CR3 defines
x86/mm, mm/hwpoison: Clear PRESENT bit for kernel 1:1 mappings of poison pages
acpi, x86/mm: Remove encryption mask from ACPI page protection type
x86/mm, kexec: Fix memory corruption with SME on successive kexecs
x86/mm/pkeys: Fix typo in Documentation/x86/protection-keys.txt
x86/mm/dump_pagetables: Speed up page tables dump for CONFIG_KASAN=y
x86/mm: Implement PCID based optimization: try to preserve old TLB entries using PCID
x86: Enable 5-level paging support via CONFIG_X86_5LEVEL=y
x86/mm: Allow userspace have mappings above 47-bit
x86/mm: Prepare to expose larger address space to userspace
x86/mpx: Do not allow MPX if we have mappings above 47-bit
x86/mm: Rename tasksize_32bit/64bit to task_size_32bit/64bit()
x86/xen: Redefine XEN_ELFNOTE_INIT_P2M using PUD_SIZE * PTRS_PER_PUD
x86/mm/dump_pagetables: Fix printout of p4d level
x86/mm/dump_pagetables: Generalize address normalization
x86/boot: Fix memremap() related build failure
...
Pull scheduler updates from Ingo Molnar:
"The main changes in this cycle were:
- fix affine wakeups (Peter Zijlstra)
- improve CPU onlining (and general bootup) scalability on systems
with ridiculous number (thousands) of CPUs (Peter Zijlstra)
- sched/numa updates (Rik van Riel)
- sched/deadline updates (Byungchul Park)
- sched/cpufreq enhancements and related cleanups (Viresh Kumar)
- sched/debug enhancements (Xie XiuQi)
- various fixes"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
sched/debug: Optimize sched_domain sysctl generation
sched/topology: Avoid pointless rebuild
sched/topology, cpuset: Avoid spurious/wrong domain rebuilds
sched/topology: Improve comments
sched/topology: Fix memory leak in __sdt_alloc()
sched/completion: Document that reinit_completion() must be called after complete_all()
sched/autogroup: Fix error reporting printk text in autogroup_create()
sched/fair: Fix wake_affine() for !NUMA_BALANCING
sched/debug: Intruduce task_state_to_char() helper function
sched/debug: Show task state in /proc/sched_debug
sched/debug: Use task_pid_nr_ns in /proc/$pid/sched
sched/core: Remove unnecessary initialization init_idle_bootup_task()
sched/deadline: Change return value of cpudl_find()
sched/deadline: Make find_later_rq() choose a closer CPU in topology
sched/numa: Scale scan period with tasks in group and shared/private
sched/numa: Slow down scan rate if shared faults dominate
sched/pelt: Fix false running accounting
sched: Mark pick_next_task_dl() and build_sched_domain() as static
sched/cpupri: Don't re-initialize 'struct cpupri'
sched/deadline: Don't re-initialize 'struct cpudl'
...
The allocated debug objects are either on the free list or in the
hashed bucket lists. So they won't get lost. However if both debug
objects and kmemleak are enabled and kmemleak scanning is done
while some of the debug objects are transitioning from one list to
the others, false negative reporting of memory leaks may happen for
those objects. For example,
[38687.275678] kmemleak: 12 new suspected memory leaks (see
/sys/kernel/debug/kmemleak)
unreferenced object 0xffff92e98aabeb68 (size 40):
comm "ksmtuned", pid 4344, jiffies 4298403600 (age 906.430s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 d0 bc db 92 e9 92 ff ff ................
01 00 00 00 00 00 00 00 38 36 8a 61 e9 92 ff ff ........86.a....
backtrace:
[<ffffffff8fa5378a>] kmemleak_alloc+0x4a/0xa0
[<ffffffff8f47c019>] kmem_cache_alloc+0xe9/0x320
[<ffffffff8f62ed96>] __debug_object_init+0x3e6/0x400
[<ffffffff8f62ef01>] debug_object_activate+0x131/0x210
[<ffffffff8f330d9f>] __call_rcu+0x3f/0x400
[<ffffffff8f33117d>] call_rcu_sched+0x1d/0x20
[<ffffffff8f4a183c>] put_object+0x2c/0x40
[<ffffffff8f4a188c>] __delete_object+0x3c/0x50
[<ffffffff8f4a18bd>] delete_object_full+0x1d/0x20
[<ffffffff8fa535c2>] kmemleak_free+0x32/0x80
[<ffffffff8f47af07>] kmem_cache_free+0x77/0x350
[<ffffffff8f453912>] unlink_anon_vmas+0x82/0x1e0
[<ffffffff8f440341>] free_pgtables+0xa1/0x110
[<ffffffff8f44af91>] exit_mmap+0xc1/0x170
[<ffffffff8f29db60>] mmput+0x80/0x150
[<ffffffff8f2a7609>] do_exit+0x2a9/0xd20
The references in the debug objects may also hide a real memory leak.
As there is no point in having kmemleak to track debug object
allocations, kmemleak checking is now disabled for debug objects.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1502718733-8527-1-git-send-email-longman@redhat.com
init_idle_bootup_task( ) is called in rest_init( ) to switch
the scheduling class of the boot thread to the idle class.
the function only sets:
idle->sched_class = &idle_sched_class;
which has been set in init_idle() called by sched_init():
/*
* The idle tasks have their own, simple scheduling class:
*/
idle->sched_class = &idle_sched_class;
We've already set the boot thread to idle class in
start_kernel()->sched_init()->init_idle()
so it's unnecessary to set it again in
start_kernel()->rest_init()->init_idle_bootup_task()
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>
Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <akpm@linux-foundation.org>
Cc: <huawei.libin@huawei.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1501838377-109720-1-git-send-email-cj.chengjian@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The percpu memory allocator is experiencing scalability issues when
allocating and freeing large numbers of counters as in BPF.
Additionally, there is a corner case where iteration is triggered over
all chunks if the contig_hint is the right size, but wrong alignment.
This patch replaces the area map allocator with a basic bitmap allocator
implementation. Each subsequent patch will introduce new features and
replace full scanning functions with faster non-scanning options when
possible.
Implementation:
This patchset removes the area map allocator in favor of a bitmap
allocator backed by metadata blocks. The primary goal is to provide
consistency in performance and memory footprint with a focus on small
allocations (< 64 bytes). The bitmap removes the heavy memmove from the
freeing critical path and provides a consistent memory footprint. The
metadata blocks provide a bound on the amount of scanning required by
maintaining a set of hints.
In an effort to make freeing fast, the metadata is updated on the free
path if the new free area makes a page free, a block free, or spans
across blocks. This causes the chunk's contig hint to potentially be
smaller than what it could allocate by up to the smaller of a page or a
block. If the chunk's contig hint is contained within a block, a check
occurs and the hint is kept accurate. Metadata is always kept accurate
on allocation, so there will not be a situation where a chunk has a
later contig hint than available.
Evaluation:
I have primarily done testing against a simple workload of allocation of
1 million objects (2^20) of varying size. Deallocation was done by in
order, alternating, and in reverse. These numbers were collected after
rebasing ontop of a80099a152. I present the worst-case numbers here:
Area Map Allocator:
Object Size | Alloc Time (ms) | Free Time (ms)
----------------------------------------------
4B | 310 | 4770
16B | 557 | 1325
64B | 436 | 273
256B | 776 | 131
1024B | 3280 | 122
Bitmap Allocator:
Object Size | Alloc Time (ms) | Free Time (ms)
----------------------------------------------
4B | 490 | 70
16B | 515 | 75
64B | 610 | 80
256B | 950 | 100
1024B | 3520 | 200
This data demonstrates the inability for the area map allocator to
handle less than ideal situations. In the best case of reverse
deallocation, the area map allocator was able to perform within range
of the bitmap allocator. In the worst case situation, freeing took
nearly 5 seconds for 1 million 4-byte objects. The bitmap allocator
dramatically improves the consistency of the free path. The small
allocations performed nearly identical regardless of the freeing
pattern.
While it does add to the allocation latency, the allocation scenario
here is optimal for the area map allocator. The area map allocator runs
into trouble when it is allocating in chunks where the latter half is
full. It is difficult to replicate this, so I present a variant where
the pages are second half filled. Freeing was done sequentially. Below
are the numbers for this scenario:
Area Map Allocator:
Object Size | Alloc Time (ms) | Free Time (ms)
----------------------------------------------
4B | 4118 | 4892
16B | 1651 | 1163
64B | 598 | 285
256B | 771 | 158
1024B | 3034 | 160
Bitmap Allocator:
Object Size | Alloc Time (ms) | Free Time (ms)
----------------------------------------------
4B | 481 | 67
16B | 506 | 69
64B | 636 | 75
256B | 892 | 90
1024B | 3262 | 147
The data shows a parabolic curve of performance for the area map
allocator. This is due to the memmove operation being the dominant cost
with the lower object sizes as more objects are packed in a chunk and at
higher object sizes, the traversal of the chunk slots is the dominating
cost. The bitmap allocator suffers this problem as well. The above data
shows the inability to scale for the allocation path with the area map
allocator and that the bitmap allocator demonstrates consistent
performance in general.
The second problem of additional scanning can result in the area map
allocator completing in 52 minutes when trying to allocate 1 million
4-byte objects with 8-byte alignment. The same workload takes
approximately 16 seconds to complete for the bitmap allocator.
V2:
Fixed a bug in pcpu_alloc_first_chunk end_offset was setting the bitmap
using bytes instead of bits.
Added a comment to pcpu_cnt_pop_pages to explain bitmap_weight.
Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Since DMA addresses will effectively look like 48-bit addresses when the
memory encryption mask is set, SWIOTLB is needed if the DMA mask of the
device performing the DMA does not support 48-bits. SWIOTLB will be
initialized to create decrypted bounce buffers for use by these devices.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Toshimitsu Kani <toshi.kani@hpe.com>
Cc: kasan-dev@googlegroups.com
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/aa2d29b78ae7d508db8881e46a3215231b9327a7.1500319216.git.thomas.lendacky@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The add_device_randomness() function would ignore incoming bytes if the
crng wasn't ready. This additionally makes sure to make an early enough
call to add_latent_entropy() to influence the initial stack canary,
which is especially important on non-x86 systems where it stays the same
through the life of the boot.
Link: http://lkml.kernel.org/r/20170626233038.GA48751@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Lokesh Vutla <lokeshvutla@ti.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
might_sleep() and smp_processor_id() checks are enabled after the boot
process is done. That hides bugs in the SMP bringup and driver
initialization code.
Enable it right when the scheduler starts working, i.e. when init task and
kthreadd have been created and right before the idle task enables
preemption.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184736.272225698@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Some of the boot code in init_kernel_freeable() which runs before SMP
bringup assumes (rightfully) that it runs on the boot CPU and therefore can
use smp_processor_id() in preemptible context.
That works so far because the smp_processor_id() check starts to be
effective after smp bringup. That's just wrong. Starting with SMP bringup
and the ability to move threads around, smp_processor_id() in preemptible
context is broken.
Aside of that it does not make sense to allow init to run on all CPUs
before sched_smp_init() has been run.
Pin the init to the boot CPU so the existing code can continue to use
smp_processor_id() without triggering the checks when the enabling of those
checks starts earlier.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184734.943149935@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Here is the "big" TTY/Serial patch updates for 4.12-rc1
Not a lot of new things here, the normal number of serial driver updates
and additions, tiny bugs fixed, and some core files split up to make
future changes a bit easier for Nicolas's "tiny-tty" work.
All of these have been in linux-next for a while. There will be a merge
conflict with include/linux/serdev.h coming from the bluetooth tree
merge, which we knew about, as we wanted some of the serdev changes to
go in through that tree. I'll send the expected merge result as a
follow-on message.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial updates from Greg KH:
"Here is the "big" TTY/Serial patch updates for 4.12-rc1
Not a lot of new things here, the normal number of serial driver
updates and additions, tiny bugs fixed, and some core files split up
to make future changes a bit easier for Nicolas's "tiny-tty" work.
All of these have been in linux-next for a while"
* tag 'tty-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (62 commits)
serial: small Makefile reordering
tty: split job control support into a file of its own
tty: move baudrate handling code to a file of its own
console: move console_init() out of tty_io.c
serial: 8250_early: Add earlycon support for Palmchip UART
tty: pl011: use "qdf2400_e44" as the earlycon name for QDF2400 E44
vt: make mouse selection of non-ASCII consistent
vt: set mouse selection word-chars to gpm's default
imx-serial: Reduce RX DMA startup latency when opening for reading
serial: omap: suspend device on probe errors
serial: omap: fix runtime-pm handling on unbind
tty: serial: omap: add UPF_BOOT_AUTOCONF flag for DT init
serial: samsung: Remove useless spinlock
serial: samsung: Add missing checks for dma_map_single failure
serial: samsung: Use right device for DMA-mapping calls
serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off
tty: fix comment typo s/repsonsible/responsible/
tty: amba-pl011: Fix spurious TX interrupts
serial: xuartps: Enable clocks in the pm disable case also
serial: core: Re-use struct uart_port {name} field
...
o Pretty much a full rewrite of the processing of function plugins.
i.e. echo do_IRQ:stacktrace > set_ftrace_filter
o The rewrite was needed to add plugins to be unique to tracing instances.
i.e. mkdir instance/foo; cd instances/foo; echo do_IRQ:stacktrace > set_ftrace_filter
The old way was written very hacky. This removes a lot of those hacks.
o New "function-fork" tracing option. When set, pids in the set_ftrace_pid
will have their children added when the processes with their pids
listed in the set_ftrace_pid file forks.
o Exposure of "maxactive" for kretprobe in kprobe_events
o Allow for builtin init functions to be traced by the function tracer
(via the kernel command line). Module init function tracing will come
in the next release.
o Added more selftests, and have selftests also test in an instance.
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Merge tag 'trace-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"New features for this release:
- Pretty much a full rewrite of the processing of function plugins.
i.e. echo do_IRQ:stacktrace > set_ftrace_filter
- The rewrite was needed to add plugins to be unique to tracing
instances. i.e. mkdir instance/foo; cd instances/foo; echo
do_IRQ:stacktrace > set_ftrace_filter The old way was written very
hacky. This removes a lot of those hacks.
- New "function-fork" tracing option. When set, pids in the
set_ftrace_pid will have their children added when the processes
with their pids listed in the set_ftrace_pid file forks.
- Exposure of "maxactive" for kretprobe in kprobe_events
- Allow for builtin init functions to be traced by the function
tracer (via the kernel command line). Module init function tracing
will come in the next release.
- Added more selftests, and have selftests also test in an instance"
* tag 'trace-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (60 commits)
ring-buffer: Return reader page back into existing ring buffer
selftests: ftrace: Allow some event trigger tests to run in an instance
selftests: ftrace: Have some basic tests run in a tracing instance too
selftests: ftrace: Have event tests also run in an tracing instance
selftests: ftrace: Make func_event_triggers and func_traceonoff_triggers tests do instances
selftests: ftrace: Allow some tests to be run in a tracing instance
tracing/ftrace: Allow for instances to trigger their own stacktrace probes
tracing/ftrace: Allow for the traceonoff probe be unique to instances
tracing/ftrace: Enable snapshot function trigger to work with instances
tracing/ftrace: Allow instances to have their own function probes
tracing/ftrace: Add a better way to pass data via the probe functions
ftrace: Dynamically create the probe ftrace_ops for the trace_array
tracing: Pass the trace_array into ftrace_probe_ops functions
tracing: Have the trace_array hold the list of registered func probes
ftrace: If the hash for a probe fails to update then free what was initialized
ftrace: Have the function probes call their own function
ftrace: Have each function probe use its own ftrace_ops
ftrace: Have unregister_ftrace_function_probe_func() return a value
ftrace: Add helper function ftrace_hash_move_and_update_ops()
ftrace: Remove data field from ftrace_func_probe structure
...
Add a tab before it to follow standard practices. Also add the missing
full stop '.'.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
All the console driver handling code lives in printk.c.
Move console_init() there as well so console support can still be used
when the TTY code is configured out. No logical changes from this patch.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Relying on free_reserved_area() to call ftrace to free init memory proved to
not be sufficient. The issue is that on x86, when debug_pagealloc is
enabled, the init memory is not freed, but simply set as not present. Since
ftrace was uninformed of this, starting function tracing still tries to
update pages that are not present according to the page tables, causing
ftrace to bug, as well as killing the kernel itself.
Instead of relying on free_reserved_area(), have init/main.c call ftrace
directly just before it frees the init memory. Then it needs to use
__init_begin and __init_end to know where the init memory location is.
Looking at all archs (and testing what I can), it appears that this should
work for each of them.
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Yang Li has reported that drain_all_pages triggers a WARN_ON which means
that this function is called earlier than the mm_percpu_wq is
initialized on arm64 with CMA configured:
WARNING: CPU: 2 PID: 1 at mm/page_alloc.c:2423 drain_all_pages+0x244/0x25c
Modules linked in:
CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.11.0-rc1-next-20170310-00027-g64dfbc5 #127
Hardware name: Freescale Layerscape 2088A RDB Board (DT)
task: ffffffc07c4a6d00 task.stack: ffffffc07c4a8000
PC is at drain_all_pages+0x244/0x25c
LR is at start_isolate_page_range+0x14c/0x1f0
[...]
drain_all_pages+0x244/0x25c
start_isolate_page_range+0x14c/0x1f0
alloc_contig_range+0xec/0x354
cma_alloc+0x100/0x1fc
dma_alloc_from_contiguous+0x3c/0x44
atomic_pool_init+0x7c/0x208
arm64_dma_init+0x44/0x4c
do_one_initcall+0x38/0x128
kernel_init_freeable+0x1a0/0x240
kernel_init+0x10/0xfc
ret_from_fork+0x10/0x20
Fix this by moving the whole setup_vmstat which is an initcall right now
to init_mm_internals which will be called right after the WQ subsystem
is initialized.
Link: http://lkml.kernel.org/r/20170315164021.28532-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Yang Li <pku.leo@gmail.com>
Tested-by: Yang Li <pku.leo@gmail.com>
Tested-by: Xiaolong Ye <xiaolong.ye@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Initialize the ftrace records immediately after memory initialization, as
that is all that is required for the records to be created. This will allow
for future work to get function tracing started earlier in the boot process.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Create an early_trace_init() function that will initialize the buffers and
allow for ealier use of trace_printk(). This will also allow for future work
to have function tracing start earlier at boot up.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
getrandom(2). It's faster and arguably more secure than cut-down MD5
that we had been using.
Also do some code cleanup.
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Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random
Pull random updates from Ted Ts'o:
"Change get_random_{int,log} to use the CRNG used by /dev/urandom and
getrandom(2). It's faster and arguably more secure than cut-down MD5
that we had been using.
Also do some code cleanup"
* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
random: move random_min_urandom_seed into CONFIG_SYSCTL ifdef block
random: convert get_random_int/long into get_random_u32/u64
random: use chacha20 for get_random_int/long
random: fix comment for unused random_min_urandom_seed
random: remove variable limit
random: remove stale urandom_init_wait
random: remove stale maybe_reseed_primary_crng
