diff options
| author | Vasily Gorbik <gor@linux.ibm.com> | 2021-04-28 16:29:40 +0200 |
|---|---|---|
| committer | Vasily Gorbik <gor@linux.ibm.com> | 2022-03-27 22:18:39 +0200 |
| commit | d81675b60d0959cfa3727f03d5b90558fb457011 (patch) | |
| tree | b2a3051b67ebf5ea4a58a73195c5b2193da65713 /arch | |
| parent | 09bc20c8fb35cf1afed1612b287e9ddbe6a7d73c (diff) | |
| download | linux-d81675b60d0959cfa3727f03d5b90558fb457011.tar.bz2 | |
s390/unwind: recover kretprobe modified return address in stacktrace
Based on commit cd9bc2c92588 ("arm64: Recover kretprobe modified return
address in stacktrace").
"""
Since the kretprobe replaces the function return address with
the __kretprobe_trampoline on the stack, stack unwinder shows it
instead of the correct return address.
This checks whether the next return address is the
__kretprobe_trampoline(), and if so, try to find the correct
return address from the kretprobe instance list.
"""
Original patch series:
https://lore.kernel.org/all/163163030719.489837.2236069935502195491.stgit@devnote2/
Reviewed-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/s390/include/asm/unwind.h | 13 | ||||
| -rw-r--r-- | arch/s390/kernel/unwind_bc.c | 8 |
2 files changed, 15 insertions, 6 deletions
diff --git a/arch/s390/include/asm/unwind.h b/arch/s390/include/asm/unwind.h index 5ebf534ef753..0bf06f1682d8 100644 --- a/arch/s390/include/asm/unwind.h +++ b/arch/s390/include/asm/unwind.h @@ -4,6 +4,8 @@ #include <linux/sched.h> #include <linux/ftrace.h> +#include <linux/kprobes.h> +#include <linux/llist.h> #include <asm/ptrace.h> #include <asm/stacktrace.h> @@ -36,10 +38,21 @@ struct unwind_state { struct pt_regs *regs; unsigned long sp, ip; int graph_idx; + struct llist_node *kr_cur; bool reliable; bool error; }; +/* Recover the return address modified by kretprobe and ftrace_graph. */ +static inline unsigned long unwind_recover_ret_addr(struct unwind_state *state, + unsigned long ip) +{ + ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, ip, NULL); + if (is_kretprobe_trampoline(ip)) + ip = kretprobe_find_ret_addr(state->task, (void *)state->sp, &state->kr_cur); + return ip; +} + void __unwind_start(struct unwind_state *state, struct task_struct *task, struct pt_regs *regs, unsigned long first_frame); bool unwind_next_frame(struct unwind_state *state); diff --git a/arch/s390/kernel/unwind_bc.c b/arch/s390/kernel/unwind_bc.c index 707fd99f6734..984970389bab 100644 --- a/arch/s390/kernel/unwind_bc.c +++ b/arch/s390/kernel/unwind_bc.c @@ -103,13 +103,11 @@ bool unwind_next_frame(struct unwind_state *state) if (sp & 0x7) goto out_err; - ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, ip, (void *) sp); - /* Update unwind state */ state->sp = sp; - state->ip = ip; state->regs = regs; state->reliable = reliable; + state->ip = unwind_recover_ret_addr(state, ip); return true; out_err: @@ -161,12 +159,10 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task, ip = READ_ONCE_NOCHECK(sf->gprs[8]); } - ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, ip, NULL); - /* Update unwind state */ state->sp = sp; - state->ip = ip; state->reliable = true; + state->ip = unwind_recover_ret_addr(state, ip); if (!first_frame) return; |