signal.c: save the original sighandlers for fatal signals

On Android, a signal handler that is not SIG_DFL is set by default for
SIGSEGV.  Ruby's install_sighandler inserts Ruby's handler only when the
signal has no handler, so it does not insert Ruby's SEGV report handler,
which caused some test failures.

This changeset forces to install Ruby's handler for some fatal signals
(sigbus, sigsegv, and sigill).  They keep the original handlers, and
call them when the interpreter receives the signals.
This commit is contained in:
Yusuke Endoh 2019-10-09 23:13:59 +09:00
parent dd477df411
commit 891cbd66a4
3 changed files with 25 additions and 13 deletions

View File

@ -599,7 +599,7 @@ rb_bug(const char *fmt, ...)
} }
void void
rb_bug_for_fatal_signal(const void *ctx, const char *fmt, ...) rb_bug_for_fatal_signal(RETSIGTYPE (*default_sighandler)(int), int sig, const void *ctx, const char *fmt, ...)
{ {
const char *file = NULL; const char *file = NULL;
int line = 0; int line = 0;
@ -610,6 +610,8 @@ rb_bug_for_fatal_signal(const void *ctx, const char *fmt, ...)
report_bug(file, line, fmt, ctx); report_bug(file, line, fmt, ctx);
if (default_sighandler) default_sighandler(sig);
die(); die();
} }

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@ -918,6 +918,7 @@ NOINLINE(static void check_reserved_signal_(const char *name, size_t name_len));
#ifdef SIGBUS #ifdef SIGBUS
static sighandler_t default_sigbus_handler;
NORETURN(static ruby_sigaction_t sigbus); NORETURN(static ruby_sigaction_t sigbus);
static RETSIGTYPE static RETSIGTYPE
@ -933,12 +934,13 @@ sigbus(int sig SIGINFO_ARG)
#if defined __APPLE__ || defined __linux__ #if defined __APPLE__ || defined __linux__
CHECK_STACK_OVERFLOW(); CHECK_STACK_OVERFLOW();
#endif #endif
rb_bug_for_fatal_signal(SIGINFO_CTX, "Bus Error" MESSAGE_FAULT_ADDRESS); rb_bug_for_fatal_signal(default_sigbus_handler, sig, SIGINFO_CTX, "Bus Error" MESSAGE_FAULT_ADDRESS);
} }
#endif #endif
#ifdef SIGSEGV #ifdef SIGSEGV
static sighandler_t default_sigsegv_handler;
NORETURN(static ruby_sigaction_t sigsegv); NORETURN(static ruby_sigaction_t sigsegv);
static RETSIGTYPE static RETSIGTYPE
@ -946,12 +948,13 @@ sigsegv(int sig SIGINFO_ARG)
{ {
check_reserved_signal("SEGV"); check_reserved_signal("SEGV");
CHECK_STACK_OVERFLOW(); CHECK_STACK_OVERFLOW();
rb_bug_for_fatal_signal(SIGINFO_CTX, "Segmentation fault" MESSAGE_FAULT_ADDRESS); rb_bug_for_fatal_signal(default_sigsegv_handler, sig, SIGINFO_CTX, "Segmentation fault" MESSAGE_FAULT_ADDRESS);
} }
#endif #endif
#ifdef SIGILL #ifdef SIGILL
static sighandler_t default_sigill_handler;
NORETURN(static ruby_sigaction_t sigill); NORETURN(static ruby_sigaction_t sigill);
static RETSIGTYPE static RETSIGTYPE
@ -961,7 +964,7 @@ sigill(int sig SIGINFO_ARG)
#if defined __APPLE__ #if defined __APPLE__
CHECK_STACK_OVERFLOW(); CHECK_STACK_OVERFLOW();
#endif #endif
rb_bug_for_fatal_signal(SIGINFO_CTX, "Illegal instruction" MESSAGE_FAULT_ADDRESS); rb_bug_for_fatal_signal(default_sigill_handler, sig, SIGINFO_CTX, "Illegal instruction" MESSAGE_FAULT_ADDRESS);
} }
#endif #endif
@ -1432,21 +1435,28 @@ sig_list(VALUE _)
perror(failed); \ perror(failed); \
} while (0) } while (0)
static int static int
install_sighandler(int signum, sighandler_t handler) install_sighandler_core(int signum, sighandler_t handler, sighandler_t *old_handler)
{ {
sighandler_t old; sighandler_t old;
old = ruby_signal(signum, handler); old = ruby_signal(signum, handler);
if (old == SIG_ERR) return -1; if (old == SIG_ERR) return -1;
if (old_handler) {
*old_handler = (old == SIG_DFL || old == SIG_IGN) ? 0 : old;
}
else {
/* signal handler should be inherited during exec. */ /* signal handler should be inherited during exec. */
if (old != SIG_DFL) { if (old != SIG_DFL) {
ruby_signal(signum, old); ruby_signal(signum, old);
} }
}
return 0; return 0;
} }
# define install_sighandler(signum, handler) \ # define install_sighandler(signum, handler) \
INSTALL_SIGHANDLER(install_sighandler(signum, handler), #signum, signum) INSTALL_SIGHANDLER(install_sighandler_core(signum, handler, NULL), #signum, signum)
# define force_install_sighandler(signum, handler, old_handler) \
INSTALL_SIGHANDLER(install_sighandler_core(signum, handler, old_handler), #signum, signum)
#if RUBY_SIGCHLD #if RUBY_SIGCHLD
static int static int
@ -1558,14 +1568,14 @@ Init_signal(void)
if (!ruby_enable_coredump) { if (!ruby_enable_coredump) {
#ifdef SIGBUS #ifdef SIGBUS
install_sighandler(SIGBUS, (sighandler_t)sigbus); force_install_sighandler(SIGBUS, (sighandler_t)sigbus, &default_sigbus_handler);
#endif #endif
#ifdef SIGILL #ifdef SIGILL
install_sighandler(SIGILL, (sighandler_t)sigill); force_install_sighandler(SIGILL, (sighandler_t)sigill, &default_sigill_handler);
#endif #endif
#ifdef SIGSEGV #ifdef SIGSEGV
RB_ALTSTACK_INIT(GET_VM()->main_altstack); RB_ALTSTACK_INIT(GET_VM()->main_altstack);
install_sighandler(SIGSEGV, (sighandler_t)sigsegv); force_install_sighandler(SIGSEGV, (sighandler_t)sigsegv, &default_sigsegv_handler);
#endif #endif
} }
#ifdef SIGPIPE #ifdef SIGPIPE

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@ -1624,7 +1624,7 @@ extern void rb_vmdebug_debug_print_post(const rb_execution_context_t *ec, const
#define SDR() rb_vmdebug_stack_dump_raw(GET_EC(), GET_EC()->cfp) #define SDR() rb_vmdebug_stack_dump_raw(GET_EC(), GET_EC()->cfp)
#define SDR2(cfp) rb_vmdebug_stack_dump_raw(GET_EC(), (cfp)) #define SDR2(cfp) rb_vmdebug_stack_dump_raw(GET_EC(), (cfp))
void rb_vm_bugreport(const void *); void rb_vm_bugreport(const void *);
NORETURN(void rb_bug_for_fatal_signal(const void *, const char *fmt, ...)); NORETURN(void rb_bug_for_fatal_signal(RETSIGTYPE (*default_sighandler)(int), int sig, const void *, const char *fmt, ...));
/* functions about thread/vm execution */ /* functions about thread/vm execution */
RUBY_SYMBOL_EXPORT_BEGIN RUBY_SYMBOL_EXPORT_BEGIN