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authorAl Viro <viro@zeniv.linux.org.uk>2021-07-25 19:19:45 +0200
committerGeert Uytterhoeven <geert@linux-m68k.org>2021-09-24 13:35:01 +0200
commit50e43a57334400668952f8e551c9d87d3ed2dfef (patch)
treeddfbe66c2a1d472a4a86aa982409b2eb1c52751e
parentm68k: Handle arrivals of multiple signals correctly (diff)
downloadlinux-50e43a57334400668952f8e551c9d87d3ed2dfef.tar.xz
linux-50e43a57334400668952f8e551c9d87d3ed2dfef.zip
m68k: Update ->thread.esp0 before calling syscall_trace() in ret_from_signal
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 <viro@zeniv.linux.org.uk> Fixes: bd6f56a75bb2 ("m68k: Missing syscall_trace() on sigreturn") Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Reviewed-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Finn Thain <fthain@linux-m68k.org> Link: https://lore.kernel.org/r/YP2dMWeV1LkHiOpr@zeniv-ca.linux.org.uk Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
-rw-r--r--arch/m68k/kernel/entry.S2
1 files changed, 2 insertions, 0 deletions
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