From 83a379cfbd283b387919fe05d44eb4c49e155ad6 Mon Sep 17 00:00:00 2001

From: Lukasz Florczak <lukasz.florczak@linux.intel.com>

Date: Mon, 21 Feb 2022 13:05:20 +0100

Subject: [PATCH 05/12] Replace error prone signal() with sigaction()

Up to this date signal() was used which implementation could vary [1].

Sigaction() call is preferred. This commit introduces replacement

from signal() to sigaction() by the use of signal_s() wrapper.

Also remove redundant signal.h header includes.

[1] https://man7.org/linux/man-pages/man2/signal.2.html

Signed-off-by: Lukasz Florczak <lukasz.florczak@linux.intel.com>

Signed-off-by: Jes Sorensen <jsorensen@fb.com>

---

 Grow.c       |  4 ++--

 Monitor.c    |  5 +++--

 managemon.c  |  1 -

 mdadm.h      | 22 ++++++++++++++++++++++

 mdmon.c      |  1 -

 monitor.c    |  1 -

 probe_roms.c |  6 +++---

 raid6check.c | 25 +++++++++++++++----------

 util.c       |  1 -

 9 files changed, 45 insertions(+), 21 deletions(-)

diff --git a/Grow.c b/Grow.c

index aa72490b..18c5719b 100644

--- a/Grow.c

+++ b/Grow.c

@@ -26,7 +26,6 @@

 #include	<sys/mman.h>

 #include	<stddef.h>

 #include	<stdint.h>

-#include	<signal.h>

 #include	<sys/wait.h>

 #if ! defined(__BIG_ENDIAN) && ! defined(__LITTLE_ENDIAN)

@@ -3566,7 +3565,8 @@ started:

 		fd = -1;

 	mlockall(MCL_FUTURE);

-	signal(SIGTERM, catch_term);

+	if (signal_s(SIGTERM, catch_term) == SIG_ERR)

+		goto release;

 	if (st->ss->external) {

 		/* metadata handler takes it from here */

diff --git a/Monitor.c b/Monitor.c

index 30c031a2..c0ab5412 100644

--- a/Monitor.c

+++ b/Monitor.c

@@ -26,7 +26,6 @@

 #include	"md_p.h"

 #include	"md_u.h"

 #include	<sys/wait.h>

-#include	<signal.h>

 #include	<limits.h>

 #include	<syslog.h>

 #ifndef NO_LIBUDEV

@@ -435,8 +434,10 @@ static void alert(char *event, char *dev, char *disc, struct alert_info *info)

 		if (mp) {

 			FILE *mdstat;

 			char hname[256];

+

 			gethostname(hname, sizeof(hname));

-			signal(SIGPIPE, SIG_IGN);

+			signal_s(SIGPIPE, SIG_IGN);

+

 			if (info->mailfrom)

 				fprintf(mp, "From: %s\n", info->mailfrom);

 			else

diff --git a/managemon.c b/managemon.c

index bb7334cf..0e9bdf00 100644

--- a/managemon.c

+++ b/managemon.c

@@ -106,7 +106,6 @@

 #include	"mdmon.h"

 #include	<sys/syscall.h>

 #include	<sys/socket.h>

-#include	<signal.h>

 static void close_aa(struct active_array *aa)

 {

diff --git a/mdadm.h b/mdadm.h

index c7268a71..26e7e5cd 100644

--- a/mdadm.h

+++ b/mdadm.h

@@ -46,6 +46,7 @@ extern __off64_t lseek64 __P ((int __fd, __off64_t __offset, int __whence));

 #include	<string.h>

 #include	<syslog.h>

 #include	<stdbool.h>

+#include	<signal.h>

 /* Newer glibc requires sys/sysmacros.h directly for makedev() */

 #include	<sys/sysmacros.h>

 #ifdef __dietlibc__

@@ -1729,6 +1730,27 @@ static inline char *to_subarray(struct mdstat_ent *ent, char *container)

 	return &ent->metadata_version[10+strlen(container)+1];

 }

+/**

+ * signal_s() - Wrapper for sigaction() with signal()-like interface.

+ * @sig: The signal to set the signal handler to.

+ * @handler: The signal handler.

+ *

+ * Return: previous handler or SIG_ERR on failure.

+ */

+static inline sighandler_t signal_s(int sig, sighandler_t handler)

+{

+	struct sigaction new_act;

+	struct sigaction old_act;

+

+	new_act.sa_handler = handler;

+	new_act.sa_flags = 0;

+

+	if (sigaction(sig, &new_act, &old_act) == 0)

+		return old_act.sa_handler;

+

+	return SIG_ERR;

+}

+

 #ifdef DEBUG

 #define dprintf(fmt, arg...) \

 	fprintf(stderr, "%s: %s: "fmt, Name, __func__, ##arg)

diff --git a/mdmon.c b/mdmon.c

index c71e62c6..5570574b 100644

--- a/mdmon.c

+++ b/mdmon.c

@@ -56,7 +56,6 @@

 #include	<errno.h>

 #include	<string.h>

 #include	<fcntl.h>

-#include	<signal.h>

 #include	<dirent.h>

 #ifdef USE_PTHREADS

 #include	<pthread.h>

diff --git a/monitor.c b/monitor.c

index e0d3be67..b877e595 100644

--- a/monitor.c

+++ b/monitor.c

@@ -22,7 +22,6 @@

 #include "mdmon.h"

 #include <sys/syscall.h>

 #include <sys/select.h>

-#include <signal.h>

 static char *array_states[] = {

 	"clear", "inactive", "suspended", "readonly", "read-auto",

diff --git a/probe_roms.c b/probe_roms.c

index 7ea04c7a..94c80c2c 100644

--- a/probe_roms.c

+++ b/probe_roms.c

@@ -22,7 +22,6 @@

 #include "probe_roms.h"

 #include "mdadm.h"

 #include <unistd.h>

-#include <signal.h>

 #include <fcntl.h>

 #include <sys/mman.h>

 #include <sys/stat.h>

@@ -69,7 +68,8 @@ static int probe_address16(const __u16 *ptr, __u16 *val)

 void probe_roms_exit(void)

 {

-	signal(SIGBUS, SIG_DFL);

+	signal_s(SIGBUS, SIG_DFL);

+

 	if (rom_fd >= 0) {

 		close(rom_fd);

 		rom_fd = -1;

@@ -98,7 +98,7 @@ int probe_roms_init(unsigned long align)

 	if (roms_init())

 		return -1;

-	if (signal(SIGBUS, sigbus) == SIG_ERR)

+	if (signal_s(SIGBUS, sigbus) == SIG_ERR)

 		rc = -1;

 	if (rc == 0) {

 		fd = open("/dev/mem", O_RDONLY);

diff --git a/raid6check.c b/raid6check.c

index a8e6005b..99477761 100644

--- a/raid6check.c

+++ b/raid6check.c

@@ -24,7 +24,6 @@

 #include "mdadm.h"

 #include <stdint.h>

-#include <signal.h>

 #include <sys/mman.h>

 #define CHECK_PAGE_BITS (12)

@@ -130,30 +129,36 @@ void raid6_stats(int *disk, int *results, int raid_disks, int chunk_size)

 }

 int lock_stripe(struct mdinfo *info, unsigned long long start,

-		int chunk_size, int data_disks, sighandler_t *sig) {

+		int chunk_size, int data_disks, sighandler_t *sig)

+{

 	int rv;

+

+	sig[0] = signal_s(SIGTERM, SIG_IGN);

+	sig[1] = signal_s(SIGINT, SIG_IGN);

+	sig[2] = signal_s(SIGQUIT, SIG_IGN);

+

+	if (sig[0] == SIG_ERR || sig[1] == SIG_ERR || sig[2] == SIG_ERR)

+		return 1;

+

 	if(mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {

 		return 2;

 	}

-	sig[0] = signal(SIGTERM, SIG_IGN);

-	sig[1] = signal(SIGINT, SIG_IGN);

-	sig[2] = signal(SIGQUIT, SIG_IGN);

-

 	rv = sysfs_set_num(info, NULL, "suspend_lo", start * chunk_size * data_disks);

 	rv |= sysfs_set_num(info, NULL, "suspend_hi", (start + 1) * chunk_size * data_disks);

 	return rv * 256;

 }

-int unlock_all_stripes(struct mdinfo *info, sighandler_t *sig) {

+int unlock_all_stripes(struct mdinfo *info, sighandler_t *sig)

+{

 	int rv;

 	rv = sysfs_set_num(info, NULL, "suspend_lo", 0x7FFFFFFFFFFFFFFFULL);

 	rv |= sysfs_set_num(info, NULL, "suspend_hi", 0);

 	rv |= sysfs_set_num(info, NULL, "suspend_lo", 0);

-	signal(SIGQUIT, sig[2]);

-	signal(SIGINT, sig[1]);

-	signal(SIGTERM, sig[0]);

+	signal_s(SIGQUIT, sig[2]);

+	signal_s(SIGINT, sig[1]);

+	signal_s(SIGTERM, sig[0]);

 	if(munlockall() != 0)

 		return 3;

diff --git a/util.c b/util.c

index 3d05d074..cc94f96e 100644

--- a/util.c

+++ b/util.c

@@ -35,7 +35,6 @@

 #include	<poll.h>

 #include	<ctype.h>

 #include	<dirent.h>

-#include	<signal.h>

 #include	<dlfcn.h>

-- 

2.31.1