The following commit has been merged into the x86/urgent branch of tip:

Commit-ID: 2356bb4b8221d7dc8c7beb810418122ed90254c9 Gitweb: https://git.kernel.org/tip/2356bb4b8221d7dc8c7beb810418122ed90254c9 Author: Vamshi K Sthambamkadi vamshi.k.sthambamkadi@gmail.com AuthorDate: Fri, 28 Aug 2020 17:02:46 +05:30 Committer: Borislav Petkov bp@suse.de CommitterDate: Fri, 04 Sep 2020 14:40:42 +02:00

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

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: 3c88ee194c28 ("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 --- arch/x86/include/asm/ptrace.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h index 40aa69d..d8324a2 100644 --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -327,8 +327,8 @@ 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),