linux/arch
Borislav Petkov 9e4a90fd34 x86/dumpstack: Improve opcodes dumping in the code section
The code used to iterate byte-by-byte over the bytes around RIP and that
is expensive: disabling pagefaults around it, copy_from_user, etc...

Make it read the whole buffer of OPCODE_BUFSIZE size in one go. Use a
statically allocated 64 bytes buffer so that concurrent show_opcodes()
do not interleave in the output even though in the majority of the cases
it's serialized via die_lock. Except the #PF path which doesn't...

Also, do the PAGE_OFFSET check outside of the function because latter
will be reused in other context.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Link: https://lkml.kernel.org/r/20180417161124.5294-5-bp@alien8.de
2018-04-26 16:15:26 +02:00
..
alpha mm: introduce MAP_FIXED_NOREPLACE 2018-04-11 10:28:38 -07:00
arc kbuild: mark $(targets) as .SECONDARY and remove .PRECIOUS markers 2018-04-07 19:04:02 +09:00
arm Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
arm64 arm64: signal: don't force known signals to SIGKILL 2018-04-18 15:13:27 +01:00
c6x c6x: pass endianness info to sparse 2018-04-10 09:58:58 -04:00
h8300 h8300: remove extraneous __BIG_ENDIAN definition 2018-03-22 17:07:01 -07:00
hexagon
ia64 pci-v4.17-changes 2018-04-06 18:31:06 -07:00
m68k Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2018-04-09 09:15:46 -07:00
microblaze Microblaze patches for 4.17-rc1 2018-04-12 10:18:02 -07:00
mips MIPS fixes for 4.17-rc2 2018-04-20 08:25:31 -07:00
nds32 page cache: use xa_lock 2018-04-11 10:28:39 -07:00
nios2 nios2 update for v4.17-rc1 2018-04-11 16:02:18 -07:00
openrisc OpenRISC updates for v4.17 2018-04-15 12:27:58 -07:00
parisc parisc: Fix missing binfmt_elf32.o build error 2018-04-14 11:17:59 +02:00
powerpc proc: fix /proc/loadavg regression 2018-04-20 17:18:36 -07:00
riscv RISC-V changes for 4.17 2018-04-04 16:43:47 -07:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-04-20 09:15:14 -07:00
sh Merge branch 'akpm' (patches from Andrew) 2018-04-14 08:50:50 -07:00
sparc Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
um Merge git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2018-04-11 16:36:47 -07:00
unicore32 unicore32: turn flush_dcache_mmap_lock into a no-op 2018-04-11 10:28:39 -07:00
x86 x86/dumpstack: Improve opcodes dumping in the code section 2018-04-26 16:15:26 +02:00
xtensa mm: introduce MAP_FIXED_NOREPLACE 2018-04-11 10:28:38 -07:00
.gitignore
Kconfig kbuild: remove incremental linking option 2018-03-26 02:01:19 +09:00