diff options
| author | Tiwei Bie <tiwei.btw@antgroup.com> | 2026-01-06 08:12:27 +0800 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2026-01-13 19:39:09 +0100 |
| commit | f68b2d5a907b53eed99cf2efcaaae116df73c298 (patch) | |
| tree | 835f5f3c92265987e9647c993a56eca2652b484d | |
| parent | 0f61b1860cc3f52aef9036d7235ed1f017632193 (diff) | |
um: Preserve errno within signal handler
We rely on errno to determine whether a syscall has failed, so we
need to ensure that accessing errno is async-signal-safe. Currently,
we preserve the errno in sig_handler_common(), but it doesn't cover
every possible case. Let's do it in hard_handler() instead, which
is the signal handler we actually register.
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20260106001228.1531146-2-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
| -rw-r--r-- | arch/um/os-Linux/signal.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c index 327fb3c52fc7..de372b936a80 100644 --- a/arch/um/os-Linux/signal.c +++ b/arch/um/os-Linux/signal.c @@ -36,7 +36,6 @@ void (*sig_info[NSIG])(int, struct siginfo *, struct uml_pt_regs *, void *mc) = static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc) { struct uml_pt_regs r; - int save_errno = errno; r.is_user = 0; if (sig == SIGSEGV) { @@ -50,8 +49,6 @@ static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc) unblock_signals_trace(); (*sig_info[sig])(sig, si, &r, mc); - - errno = save_errno; } /* @@ -207,8 +204,11 @@ static void hard_handler(int sig, siginfo_t *si, void *p) { ucontext_t *uc = p; mcontext_t *mc = &uc->uc_mcontext; + int save_errno = errno; (*handlers[sig])(sig, (struct siginfo *)si, mc); + + errno = save_errno; } void set_handler(int sig) |