Re: [PATCH 2/3] m68k: update ->thread.esp0 before calling syscall_trace() in ret_from_signal
From: Michael Schmitz <schmitzmic@gmail.com>
Date: 2021-09-15 22:19:40
Also in:
lkml
Hi Al, On 26/07/21 5:19 am, Al Viro wrote:
We get there when sigreturn has performed obscene acts on kernel stack;
in particular, the location of pt_regs has shifted. We are about to call
syscall_trace(), which might stop for tracer. If that happens, we'd better
have task_pt_regs() returning correct result...
Fucked-up-by: Al Viro [off-list ref]
Fixes: bd6f56a75bb2 ("m68k: Missing syscall_trace() on sigreturn")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>Looking good also, and should go to -stable. Tested-by: Michael Schmitz <schmitzmic@gmail.com> Reviewed-by: Michael Schmitz <schmitzmic@gmail.com>
quoted hunk ↗ jump to hunk
--- arch/m68k/kernel/entry.S | 2 ++ 1 file changed, 2 insertions(+)diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S index 9dd76fbb7c6b..ff9e842cec0f 100644 --- a/arch/m68k/kernel/entry.S +++ b/arch/m68k/kernel/entry.S@@ -186,6 +186,8 @@ ENTRY(ret_from_signal) movel %curptr@(TASK_STACK),%a1 tstb %a1@(TINFO_FLAGS+2) jge 1f + lea %sp@(SWITCH_STACK_SIZE),%a1 + movel %a1,%curptr@(TASK_THREAD+THREAD_ESP0) jbsr syscall_trace 1: RESTORE_SWITCH_STACK addql #4,%sp