linux/arch/x86/kernel/kprobes
Masami Hiramatsu 0d07c0ec43 x86/kprobes: Fix optprobe to detect INT3 padding correctly
Commit

  7705dc8557 ("x86/vmlinux: Use INT3 instead of NOP for linker fill bytes")

changed the padding bytes between functions from NOP to INT3. However,
when optprobe decodes a target function it finds INT3 and gives up the
jump optimization.

Instead of giving up any INT3 detection, check whether the rest of the
bytes to the end of the function are INT3. If all of them are INT3,
those come from the linker. In that case, continue the optprobe jump
optimization.

 [ bp: Massage commit message. ]

Fixes: 7705dc8557 ("x86/vmlinux: Use INT3 instead of NOP for linker fill bytes")
Reported-by: Adam Zabrocki <pi3@pi3.com.pl>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/160767025681.3880685.16021570341428835411.stgit@devnote2
2020-12-12 15:25:17 +01:00
..
common.h x86/stackframe/32: Provide consistent pt_regs 2019-06-25 10:23:47 +02:00
core.c objtool changes for v5.10: 2020-10-14 10:13:37 -07:00
ftrace.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
opt.c x86/kprobes: Fix optprobe to detect INT3 padding correctly 2020-12-12 15:25:17 +01:00