diff options
| -rw-r--r-- | arch/x86/include/asm/unwind.h | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/unwind_frame.c | 36 |
2 files changed, 28 insertions, 9 deletions
diff --git a/arch/x86/include/asm/unwind.h b/arch/x86/include/asm/unwind.h index 5663425f812f..9b10dcd51716 100644 --- a/arch/x86/include/asm/unwind.h +++ b/arch/x86/include/asm/unwind.h @@ -12,6 +12,7 @@ struct unwind_state { struct task_struct *task; int graph_idx; #ifdef CONFIG_FRAME_POINTER + bool got_irq; unsigned long *bp, *orig_sp; struct pt_regs *regs; unsigned long ip; diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c index c67a059c6655..c4611359b617 100644 --- a/arch/x86/kernel/unwind_frame.c +++ b/arch/x86/kernel/unwind_frame.c @@ -1,6 +1,8 @@ #include <linux/sched.h> #include <linux/sched/task.h> #include <linux/sched/task_stack.h> +#include <linux/interrupt.h> +#include <asm/sections.h> #include <asm/ptrace.h> #include <asm/bitops.h> #include <asm/stacktrace.h> @@ -72,6 +74,21 @@ static size_t regs_size(struct pt_regs *regs) return sizeof(*regs); } +static bool in_entry_code(unsigned long ip) +{ + char *addr = (char *)ip; + + if (addr >= __entry_text_start && addr < __entry_text_end) + return true; + +#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN) + if (addr >= __irqentry_text_start && addr < __irqentry_text_end) + return true; +#endif + + return false; +} + #ifdef CONFIG_X86_32 #define GCC_REALIGN_WORDS 3 #else @@ -144,6 +161,7 @@ static bool update_stack_state(struct unwind_state *state, if (regs) { frame = (unsigned long *)regs; len = regs_size(regs); + state->got_irq = true; } else { frame = next_bp; len = FRAME_HEADER_SIZE; @@ -239,16 +257,8 @@ bool unwind_next_frame(struct unwind_state *state) next_bp = (unsigned long *)READ_ONCE_TASK_STACK(state->task, *state->bp); /* Move to the next frame if it's safe: */ - if (!update_stack_state(state, next_bp)) { - /* - * Don't warn on bad regs->bp. An interrupt in entry code - * might cause a false positive warning. - */ - if (state->regs) - goto the_end; - + if (!update_stack_state(state, next_bp)) goto bad_address; - } return true; @@ -263,6 +273,13 @@ bad_address: if (state->task != current) goto the_end; + /* + * Don't warn if the unwinder got lost due to an interrupt in entry + * code before the stack was set up: + */ + if (state->got_irq && in_entry_code(state->ip)) + goto the_end; + if (state->regs) { printk_deferred_once(KERN_WARNING "WARNING: kernel stack regs at %p in %s:%d has bad 'bp' value %p\n", @@ -289,6 +306,7 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task, memset(state, 0, sizeof(*state)); state->task = task; + state->got_irq = (regs); /* Don't even attempt to start from user mode regs: */ if (regs && user_mode(regs)) { |