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authorStas Sergeev <stsp@list.ru>2017-02-27 14:27:25 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-27 18:43:45 -0800
commit441398d378f29a5ad6d0fcda07918e54e4961800 (patch)
tree29d479819be6aeb995416102d01fea238b978e74
parentb899ba7d8c71e2e1c2be281222877c7a1c2ba60d (diff)
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sigaltstack: support SS_AUTODISARM for CONFIG_COMPAT
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@list.ru Signed-off-by: Stas Sergeev <stsp@users.sourceforge.net> Cc: Milosz Tanski <milosz@adfin.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Waiman Long <Waiman.Long@hpe.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Safonov <dsafonov@virtuozzo.com> Cc: Wang Xiaoqiang <wangxq10@lzu.edu.cn> Cc: Oleg Nesterov <oleg@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/compat.h4
-rw-r--r--kernel/signal.c11
2 files changed, 12 insertions, 3 deletions
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 9e40be522793..aef47be2a5c1 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -711,8 +711,10 @@ int __compat_save_altstack(compat_stack_t __user *, unsigned long);
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,
diff --git a/kernel/signal.c b/kernel/signal.c
index 13f9def8b24a..214a8feeb771 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3239,10 +3239,17 @@ int compat_restore_altstack(const compat_stack_t __user *uss)
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