1
0
Fork 0

tracing/kprobes, x86/ptrace: Fix regs argument order for i386

commit 2356bb4b82 upstream.

On i386, the order of parameters passed on regs is eax,edx,and ecx
(as per regparm(3) calling conventions).

Change the mapping in regs_get_kernel_argument(), so that arg1=ax
arg2=dx, and arg3=cx.

Running the selftests testcase kprobes_args_use.tc shows the result
as passed.

Fixes: 3c88ee194c ("x86: ptrace: Add function argument access API")
Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200828113242.GA1424@cosmos
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5.4-rM2-2.2.x-imx-squashed
Vamshi K Sthambamkadi 2020-08-28 17:02:46 +05:30 committed by Greg Kroah-Hartman
parent 036a857bb5
commit cc6c4d81d6
1 changed files with 1 additions and 1 deletions

View File

@ -309,8 +309,8 @@ static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
static const unsigned int argument_offs[] = {
#ifdef __i386__
offsetof(struct pt_regs, ax),
offsetof(struct pt_regs, cx),
offsetof(struct pt_regs, dx),
offsetof(struct pt_regs, cx),
#define NR_REG_ARGUMENTS 3
#else
offsetof(struct pt_regs, di),