linux/tools/arch
Borislav Petkov f96b467583 x86/insn: Use get_unaligned() instead of memcpy()
Use get_unaligned() instead of memcpy() to access potentially unaligned
memory, which, when accessed through a pointer, leads to undefined
behavior. get_unaligned() describes much better what is happening there
anyway even if memcpy() does the job.

In addition, since perf tool builds with -Werror, it would fire with:

  util/intel-pt-decoder/../../../arch/x86/lib/insn.c: In function '__insn_get_emulate_prefix':
  tools/include/../include/asm-generic/unaligned.h:10:15: error: packed attribute is unnecessary [-Werror=packed]
     10 |  const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr); \

because -Werror=packed would complain if the packed attribute would have
no effect on the layout of the structure.

In this case, that is intentional so disable the warning only for that
compilation unit.

That part is Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>

No functional changes.

Fixes: 5ba1071f75 ("x86/insn, tools/x86: Fix undefined behavior due to potential unaligned accesses")
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lkml.kernel.org/r/YVSsIkj9Z29TyUjE@zn.tnic
2021-10-06 11:56:37 +02:00
..
alpha/include tools headers uapi: Sync asm-generic/mman-common.h and linux/mman.h 2019-03-28 14:31:56 -03:00
arc/include/uapi/asm tools arch uapi: Copy missing unistd.h headers for arc, hexagon and riscv 2019-05-02 16:00:20 -04:00
arm/include tools headers kvm: Sync kvm headers with the kernel sources 2019-12-02 12:54:13 -03:00
arm64/include tools headers UAPI: Sync files changed by the memfd_secret new syscall 2021-07-14 10:05:35 -03:00
csky/include/uapi/asm csky: Add support for libdw 2019-05-15 16:36:46 -03:00
h8300/include License cleanup: add SPDX license identifier to uapi header files with no license 2017-11-02 11:19:54 +01:00
hexagon/include/uapi/asm tools arch uapi: Copy missing unistd.h headers for arc, hexagon and riscv 2019-05-02 16:00:20 -04:00
ia64/include ia64: tools: remove duplicate definition of ia64_mf() on ia64 2021-04-16 16:10:37 -07:00
microblaze/include/uapi/asm License cleanup: add SPDX license identifier to uapi header files with no license 2017-11-02 11:19:54 +01:00
mips/include perf tools: Copy uapi/asm/perf_regs.h from the kernel for MIPS 2021-06-01 10:07:46 -03:00
parisc/include/uapi/asm parisc: Add MAP_UNINITIALIZED define 2020-10-15 08:10:39 +02:00
powerpc/include tools include UAPI powerpc: Sync errno.h with the kernel headers 2021-05-10 09:01:00 -03:00
riscv/include/uapi/asm Replace HTTP links with HTTPS ones: RISC-V 2020-07-30 11:37:40 -07:00
s390/include tools headers UAPI s390: Sync ptrace.h kernel headers 2021-03-06 16:54:23 -03:00
sh/include sh: remove sh5 support 2020-06-01 14:48:52 -04:00
sparc/include tools headers UAPI: Update tools's copy of mman.h headers 2019-07-29 09:02:58 -03:00
x86 x86/insn: Use get_unaligned() instead of memcpy() 2021-10-06 11:56:37 +02:00
xtensa/include tools headers uapi: Sync asm-generic/mman-common.h and linux/mman.h 2019-03-28 14:31:56 -03:00