diff options
Diffstat (limited to 'arch/s390/kernel/stacktrace.c')
| -rw-r--r-- | arch/s390/kernel/stacktrace.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c index f8fc4f8aef9b..fc5419ac64c8 100644 --- a/arch/s390/kernel/stacktrace.c +++ b/arch/s390/kernel/stacktrace.c @@ -9,6 +9,7 @@ #include <linux/stacktrace.h> #include <asm/stacktrace.h> #include <asm/unwind.h> +#include <asm/kprobes.h> void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, struct task_struct *task, struct pt_regs *regs) @@ -22,3 +23,45 @@ void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, break; } } + +/* + * This function returns an error if it detects any unreliable features of the + * stack. Otherwise it guarantees that the stack trace is reliable. + * + * If the task is not 'current', the caller *must* ensure the task is inactive. + */ +int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry, + void *cookie, struct task_struct *task) +{ + struct unwind_state state; + unsigned long addr; + + unwind_for_each_frame(&state, task, NULL, 0) { + if (state.stack_info.type != STACK_TYPE_TASK) + return -EINVAL; + + if (state.regs) + return -EINVAL; + + addr = unwind_get_return_address(&state); + if (!addr) + return -EINVAL; + +#ifdef CONFIG_KPROBES + /* + * Mark stacktraces with kretprobed functions on them + * as unreliable. + */ + if (state.ip == (unsigned long)kretprobe_trampoline) + return -EINVAL; +#endif + + if (!consume_entry(cookie, addr, false)) + return -EINVAL; + } + + /* Check for stack corruption */ + if (unwind_error(&state)) + return -EINVAL; + return 0; +} |