ARM: 8226/1: cacheflush: get rid of restarting block

We cannot restart cacheflush safely if a process provides user-defined
signal handler and signal is pending. In this case -EINTR is returned
and it is expected that process re-invokes syscall. However, there are
a few problems with that:
 * looks like nobody bothers checking return value from cacheflush
 * but if it did, we don't provide the restart address for that, so the
   process has to use the same range again
 * ...and again, what might lead to looping forever

So, remove cacheflush restarting code and terminate cache flushing
as early as fatal signal is pending.

Cc: stable@vger.kernel.org # 3.12+
Reported-by: Chanho Min <chanho.min@lge.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Vladimir Murzin
2014-11-27 11:39:04 +01:00
committed by Russell King
parent 995ab5189d
commit 3f4aa45cee
2 changed files with 2 additions and 40 deletions

View File

@@ -44,16 +44,6 @@ struct cpu_context_save {
__u32 extra[2]; /* Xscale 'acc' register, etc */
};
struct arm_restart_block {
union {
/* For user cache flushing */
struct {
unsigned long start;
unsigned long end;
} cache;
};
};
/*
* low level task data that entry.S needs immediate access to.
* __switch_to() assumes cpu_context follows immediately after cpu_domain.
@@ -79,7 +69,6 @@ struct thread_info {
unsigned long thumbee_state; /* ThumbEE Handler Base register */
#endif
struct restart_block restart_block;
struct arm_restart_block arm_restart_block;
};
#define INIT_THREAD_INFO(tsk) \