mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-27 19:15:04 +07:00
3f0116c323
Fengguang Wu, Oleg Nesterov and Peter Zijlstra tracked down a kernel crash to a GCC bug: GCC miscompiles certain 'asm goto' constructs, as outlined here: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 Implement a workaround suggested by Jakub Jelinek. Reported-and-tested-by: Fengguang Wu <fengguang.wu@intel.com> Reported-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Suggested-by: Jakub Jelinek <jakub@redhat.com> Reviewed-by: Richard Henderson <rth@twiddle.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
38 lines
674 B
C
38 lines
674 B
C
#ifndef _ASM_S390_JUMP_LABEL_H
|
|
#define _ASM_S390_JUMP_LABEL_H
|
|
|
|
#include <linux/types.h>
|
|
|
|
#define JUMP_LABEL_NOP_SIZE 6
|
|
|
|
#ifdef CONFIG_64BIT
|
|
#define ASM_PTR ".quad"
|
|
#define ASM_ALIGN ".balign 8"
|
|
#else
|
|
#define ASM_PTR ".long"
|
|
#define ASM_ALIGN ".balign 4"
|
|
#endif
|
|
|
|
static __always_inline bool arch_static_branch(struct static_key *key)
|
|
{
|
|
asm_volatile_goto("0: brcl 0,0\n"
|
|
".pushsection __jump_table, \"aw\"\n"
|
|
ASM_ALIGN "\n"
|
|
ASM_PTR " 0b, %l[label], %0\n"
|
|
".popsection\n"
|
|
: : "X" (key) : : label);
|
|
return false;
|
|
label:
|
|
return true;
|
|
}
|
|
|
|
typedef unsigned long jump_label_t;
|
|
|
|
struct jump_entry {
|
|
jump_label_t code;
|
|
jump_label_t target;
|
|
jump_label_t key;
|
|
};
|
|
|
|
#endif
|