* [PATCH 5.10.y] m68k: Update ->thread.esp0 before calling syscall_trace() in ret_from_signal
@ 2024-11-18 5:27 Finn Thain
0 siblings, 0 replies; 2+ messages in thread
From: Finn Thain @ 2024-11-18 5:27 UTC (permalink / raw)
To: stable; +Cc: Geert Uytterhoeven, Al Viro, linux-m68k, linux-kernel
From: Al Viro <viro@zeniv.linux.org.uk>
[ Upstream commit 50e43a57334400668952f8e551c9d87d3ed2dfef ]
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>
Signed-off-by: Finn Thain <fthain@linux-m68k.org>
---
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 417d8f0e8962..0d03b4f2077b 100644
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -182,6 +182,8 @@ 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
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH 5.10.y] m68k: Update ->thread.esp0 before calling syscall_trace() in ret_from_signal
@ 2025-01-22 8:47 Finn Thain
0 siblings, 0 replies; 2+ messages in thread
From: Finn Thain @ 2025-01-22 8:47 UTC (permalink / raw)
To: stable; +Cc: Geert Uytterhoeven, Al Viro, linux-m68k, linux-kernel
From: Al Viro <viro@zeniv.linux.org.uk>
[ Upstream commit 50e43a57334400668952f8e551c9d87d3ed2dfef ]
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>
Signed-off-by: Finn Thain <fthain@linux-m68k.org>
---
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 417d8f0e8962..0d03b4f2077b 100644
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -182,6 +182,8 @@ 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
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