Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'x86-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core x86 updates from Ingo Molnar:
- x86/alternatives: Drop unnecessary test after call to
alt_replace_call() (Juergen Gross)
- x86/dumpstack: Prevent KASAN false positive warnings in
__show_regs() (Tengda Wu)
* tag 'x86-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/dumpstack: Prevent KASAN false positive warnings in __show_regs()
x86/alternative: Drop not needed test after call of alt_replace_call()
+24
-8
+3
-6
arch/x86/kernel/alternative.c
+3
-6
arch/x86/kernel/alternative.c
···
541
541
* Rewrite the "call BUG_func" replacement to point to the target of the
542
542
* indirect pv_ops call "call *disp(%ip)".
543
543
*/
544
-
static int alt_replace_call(u8 *instr, u8 *insn_buff, struct alt_instr *a)
544
+
static unsigned int alt_replace_call(u8 *instr, u8 *insn_buff, struct alt_instr *a)
545
545
{
546
546
void *target, *bug = &BUG_func;
547
547
s32 disp;
···
625
625
* order.
626
626
*/
627
627
for (a = start; a < end; a++) {
628
-
int insn_buff_sz = 0;
628
+
unsigned int insn_buff_sz = 0;
629
629
630
630
/*
631
631
* In case of nested ALTERNATIVE()s the outer alternative might
···
665
665
memcpy(insn_buff, replacement, a->replacementlen);
666
666
insn_buff_sz = a->replacementlen;
667
667
668
-
if (a->flags & ALT_FLAG_DIRECT_CALL) {
668
+
if (a->flags & ALT_FLAG_DIRECT_CALL)
669
669
insn_buff_sz = alt_replace_call(instr, insn_buff, a);
670
-
if (insn_buff_sz < 0)
671
-
continue;
672
-
}
673
670
674
671
for (; insn_buff_sz < a->instrlen; insn_buff_sz++)
675
672
insn_buff[insn_buff_sz] = 0x90;
+21
-2
arch/x86/kernel/dumpstack.c
+21
-2
arch/x86/kernel/dumpstack.c
···
181
181
* in false positive reports. Disable instrumentation to avoid those.
182
182
*/
183
183
__no_kmsan_checks
184
-
static void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
185
-
unsigned long *stack, const char *log_lvl)
184
+
static void __show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
185
+
unsigned long *stack, const char *log_lvl)
186
186
{
187
187
struct unwind_state state;
188
188
struct stack_info stack_info = {0};
···
301
301
if (stack_name)
302
302
printk("%s </%s>\n", log_lvl, stack_name);
303
303
}
304
+
}
305
+
306
+
static void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
307
+
unsigned long *stack, const char *log_lvl)
308
+
{
309
+
/*
310
+
* Disable KASAN to avoid false positives during walking another
311
+
* task's stacks, as values on these stacks may change concurrently
312
+
* with task execution.
313
+
*/
314
+
bool disable_kasan = task && task != current;
315
+
316
+
if (disable_kasan)
317
+
kasan_disable_current();
318
+
319
+
__show_trace_log_lvl(task, regs, stack, log_lvl);
320
+
321
+
if (disable_kasan)
322
+
kasan_enable_current();
304
323
}
305
324
306
325
void show_stack(struct task_struct *task, unsigned long *sp,