This is a note to let you know that I've just added the patch titled
sigaltstack: support SS_AUTODISARM for CONFIG_COMPAT
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
sigaltstack-support-ss_autodisarm-for-config_compat.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 441398d378f29a5ad6d0fcda07918e54e4961800 Mon Sep 17 00:00:00 2001
From: Stas Sergeev <stsp@xxxxxxx>
Date: Mon, 27 Feb 2017 14:27:25 -0800
Subject: sigaltstack: support SS_AUTODISARM for CONFIG_COMPAT
From: Stas Sergeev <stsp@xxxxxxx>
commit 441398d378f29a5ad6d0fcda07918e54e4961800 upstream.
Currently SS_AUTODISARM is not supported in compatibility mode, but does
not return -EINVAL either. This makes dosemu built with -m32 on x86_64
to crash. Also the kernel's sigaltstack selftest fails if compiled with
-m32.
This patch adds the needed support.
Link: http://lkml.kernel.org/r/20170205101213.8163-2-stsp@xxxxxxx
Signed-off-by: Stas Sergeev <stsp@xxxxxxxxxxxxxxxxxxxxx>
Cc: Milosz Tanski <milosz@xxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Nicolas Pitre <nicolas.pitre@xxxxxxxxxx>
Cc: Waiman Long <Waiman.Long@xxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Dmitry Safonov <dsafonov@xxxxxxxxxxxxx>
Cc: Wang Xiaoqiang <wangxq10@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/compat.h | 4 +++-
kernel/signal.c | 11 +++++++++--
2 files changed, 12 insertions(+), 3 deletions(-)
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -711,8 +711,10 @@ int __compat_save_altstack(compat_stack_
compat_stack_t __user *__uss = uss; \
struct task_struct *t = current; \
put_user_ex(ptr_to_compat((void __user *)t->sas_ss_sp), &__uss->ss_sp); \
- put_user_ex(sas_ss_flags(sp), &__uss->ss_flags); \
+ put_user_ex(t->sas_ss_flags, &__uss->ss_flags); \
put_user_ex(t->sas_ss_size, &__uss->ss_size); \
+ if (t->sas_ss_flags & SS_AUTODISARM) \
+ sas_ss_reset(t); \
} while (0);
asmlinkage long compat_sys_sched_rr_get_interval(compat_pid_t pid,
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3226,10 +3226,17 @@ int compat_restore_altstack(const compat
int __compat_save_altstack(compat_stack_t __user *uss, unsigned long sp)
{
+ int err;
struct task_struct *t = current;
- return __put_user(ptr_to_compat((void __user *)t->sas_ss_sp), &uss->ss_sp) |
- __put_user(sas_ss_flags(sp), &uss->ss_flags) |
+ err = __put_user(ptr_to_compat((void __user *)t->sas_ss_sp),
+ &uss->ss_sp) |
+ __put_user(t->sas_ss_flags, &uss->ss_flags) |
__put_user(t->sas_ss_size, &uss->ss_size);
+ if (err)
+ return err;
+ if (t->sas_ss_flags & SS_AUTODISARM)
+ sas_ss_reset(t);
+ return 0;
}
#endif
Patches currently in stable-queue which might be from stsp@xxxxxxx are
queue-4.9/sigaltstack-support-ss_autodisarm-for-config_compat.patch