diff options
Diffstat (limited to 'arch/x86/kernel/dumpstack.c')
| -rw-r--r-- | arch/x86/kernel/dumpstack.c | 56 |
1 files changed, 35 insertions, 21 deletions
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index 53de044e5654..b10684dedc58 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -23,8 +23,6 @@ #include <asm/stacktrace.h> #include <asm/unwind.h> -int panic_on_unrecovered_nmi; -int panic_on_io_nmi; static int die_counter; static struct pt_regs exec_summary_regs; @@ -81,12 +79,6 @@ static int copy_code(struct pt_regs *regs, u8 *buf, unsigned long src, /* The user space code from other tasks cannot be accessed. */ if (regs != task_pt_regs(current)) return -EPERM; - /* - * Make sure userspace isn't trying to trick us into dumping kernel - * memory by pointing the userspace instruction pointer at it. - */ - if (__chk_range_not_ok(src, nbytes, TASK_SIZE_MAX)) - return -EINVAL; /* * Even if named copy_from_user_nmi() this can be invoked from @@ -134,7 +126,7 @@ void show_opcodes(struct pt_regs *regs, const char *loglvl) /* No access to the user space stack of other tasks. Ignore. */ break; default: - printk("%sCode: Unable to access opcode bytes at RIP 0x%lx.\n", + printk("%sCode: Unable to access opcode bytes at 0x%lx.\n", loglvl, prologue); break; } @@ -183,8 +175,14 @@ static void show_regs_if_on_stack(struct stack_info *info, struct pt_regs *regs, } } -static void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, - unsigned long *stack, const char *log_lvl) +/* + * This function reads pointers from the stack and dereferences them. The + * pointers may not have their KMSAN shadow set up properly, which may result + * in false positive reports. Disable instrumentation to avoid those. + */ +__no_kmsan_checks +static void __show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, + unsigned long *stack, const char *log_lvl) { struct unwind_state state; struct stack_info stack_info = {0}; @@ -195,7 +193,7 @@ static void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, printk("%sCall Trace:\n", log_lvl); unwind_start(&state, task, regs, stack); - stack = stack ? : get_stack_pointer(task, regs); + stack = stack ?: get_stack_pointer(task, regs); regs = unwind_get_entry_regs(&state, &partial); /* @@ -214,9 +212,11 @@ static void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, * - hardirq stack * - entry stack */ - for ( ; stack; stack = PTR_ALIGN(stack_info.next_sp, sizeof(long))) { + for (; stack; stack = stack_info.next_sp) { const char *stack_name; + stack = PTR_ALIGN(stack, sizeof(long)); + if (get_stack_info(stack, task, &stack_info, &visit_mask)) { /* * We weren't on a valid stack. It's possible that @@ -303,6 +303,25 @@ next: } } +static void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, + unsigned long *stack, const char *log_lvl) +{ + /* + * Disable KASAN to avoid false positives during walking another + * task's stacks, as values on these stacks may change concurrently + * with task execution. + */ + bool disable_kasan = task && task != current; + + if (disable_kasan) + kasan_disable_current(); + + __show_trace_log_lvl(task, regs, stack, log_lvl); + + if (disable_kasan) + kasan_enable_current(); +} + void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl) { @@ -392,22 +411,17 @@ NOKPROBE_SYMBOL(oops_end); static void __die_header(const char *str, struct pt_regs *regs, long err) { - const char *pr = ""; - /* Save the regs of the first oops for the executive summary later. */ if (!die_counter) exec_summary_regs = *regs; - if (IS_ENABLED(CONFIG_PREEMPTION)) - pr = IS_ENABLED(CONFIG_PREEMPT_RT) ? " PREEMPT_RT" : " PREEMPT"; - printk(KERN_DEFAULT - "%s: %04lx [#%d]%s%s%s%s%s\n", str, err & 0xffff, ++die_counter, - pr, + "Oops: %s: %04lx [#%d]%s%s%s%s\n", str, err & 0xffff, + ++die_counter, IS_ENABLED(CONFIG_SMP) ? " SMP" : "", debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "", IS_ENABLED(CONFIG_KASAN) ? " KASAN" : "", - IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION) ? + IS_ENABLED(CONFIG_MITIGATION_PAGE_TABLE_ISOLATION) ? (boot_cpu_has(X86_FEATURE_PTI) ? " PTI" : " NOPTI") : ""); } NOKPROBE_SYMBOL(__die_header); |