diff options
| -rw-r--r-- | arch/s390/kernel/stacktrace.c | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c index 1c9e3b7739a2..b4485b0c7f06 100644 --- a/arch/s390/kernel/stacktrace.c +++ b/arch/s390/kernel/stacktrace.c @@ -77,6 +77,21 @@ static inline bool store_ip(stack_trace_consume_fn consume_entry, void *cookie, return consume_entry(cookie, ip); } +static inline bool ip_invalid(unsigned long ip) +{ + /* + * Perform some basic checks if an instruction address taken + * from unreliable source is invalid. + */ + if (ip & 1) + return true; + if (ip < mmap_min_addr) + return true; + if (ip >= current->mm->context.asce_limit) + return true; + return false; +} + void arch_stack_walk_user_common(stack_trace_consume_fn consume_entry, void *cookie, struct perf_callchain_entry_ctx *entry, const struct pt_regs *regs, bool perf) @@ -87,6 +102,8 @@ void arch_stack_walk_user_common(stack_trace_consume_fn consume_entry, void *coo if (is_compat_task()) return; + if (!current->mm) + return; ip = instruction_pointer(regs); if (!store_ip(consume_entry, cookie, entry, perf, ip)) return; @@ -101,15 +118,16 @@ void arch_stack_walk_user_common(stack_trace_consume_fn consume_entry, void *coo sf = (void __user *)sp; if (__get_user(ip, &sf->gprs[8])) break; - if (ip & 0x1) { + if (ip_invalid(ip)) { /* * If the instruction address is invalid, and this * is the first stack frame, assume r14 has not * been written to the stack yet. Otherwise exit. */ - if (first && !(regs->gprs[14] & 0x1)) - ip = regs->gprs[14]; - else + if (!first) + break; + ip = regs->gprs[14]; + if (ip_invalid(ip)) break; } if (!store_ip(consume_entry, cookie, entry, perf, ip)) |