livepatch: Use static buffer for debugging messages under rq lock

The err_buf array uses 128 bytes of stack space.  Move it off the stack
by making it static.  It's safe to use a shared buffer because
klp_try_switch_task() is called under klp_mutex.

Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
This commit is contained in:
Petr Mladek 2019-05-31 09:41:47 +02:00
parent 573de2a6e8
commit f36e664516

View File

@ -293,11 +293,11 @@ static int klp_check_stack(struct task_struct *task, char *err_buf)
*/
static bool klp_try_switch_task(struct task_struct *task)
{
static char err_buf[STACK_ERR_BUF_SIZE];
struct rq *rq;
struct rq_flags flags;
int ret;
bool success = false;
char err_buf[STACK_ERR_BUF_SIZE];
err_buf[0] = '\0';
@ -340,7 +340,6 @@ static bool klp_try_switch_task(struct task_struct *task)
pr_debug("%s", err_buf);
return success;
}
/*