From: WanBingjiang <wanbingjiang@webray.com.cn>
Date: Fri, 2 Feb 2024 02:43:08 +0000 (+0800)
Subject: sys-utils/lscpu: Unblock SIGSEGV before vmware_bdoor
X-Git-Tag: v2.40-rc2~58^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5533e237c8047ff941bb3720237c58413441e35c;p=thirdparty%2Futil-linux.git

sys-utils/lscpu: Unblock SIGSEGV before vmware_bdoor
---

diff --git a/sys-utils/lscpu-virt.c b/sys-utils/lscpu-virt.c
index 4d301271a3..6ba7c02dc6 100644
--- a/sys-utils/lscpu-virt.c
+++ b/sys-utils/lscpu-virt.c
@@ -17,6 +17,7 @@
 #include <unistd.h>
 #include <string.h>
 #include <stdio.h>
+#include <signal.h>
 
 #include "lscpu.h"
 
@@ -454,6 +455,7 @@ void vmware_bdoor(uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx)
 }
 
 static jmp_buf segv_handler_env;
+static sigset_t oset;
 
 static void
 segv_handler(__attribute__((__unused__)) int sig,
@@ -467,6 +469,7 @@ static int is_vmware_platform(void)
 {
 	uint32_t eax, ebx, ecx, edx;
 	struct sigaction act, oact;
+	sigset_t set;
 
 	/*
 	 * FIXME: Not reliable for non-root users. Note it works as expected if
@@ -485,8 +488,16 @@ static int is_vmware_platform(void)
 	 * the signal. All this magic is needed because lscpu
 	 * isn't supposed to require root privileges.
 	 */
-	if (sigsetjmp(segv_handler_env, 1))
+	if (sigsetjmp(segv_handler_env, 1)) {
+		if (sigprocmask(SIG_SETMASK, &oset, NULL))
+			err(EXIT_FAILURE, _("cannot restore signal mask"));
 		return 0;
+	}
+
+	sigemptyset(&set);
+	sigaddset(&set, SIGSEGV);
+	if (sigprocmask(SIG_UNBLOCK, &set, &oset))
+		err(EXIT_FAILURE, _("cannot unblock signal"));
 
 	memset(&act, 0, sizeof(act));
 	act.sa_sigaction = segv_handler;
@@ -500,6 +511,9 @@ static int is_vmware_platform(void)
 	if (sigaction(SIGSEGV, &oact, NULL))
 		err(EXIT_FAILURE, _("cannot restore signal handler"));
 
+	if (sigprocmask(SIG_SETMASK, &oset, NULL))
+		err(EXIT_FAILURE, _("cannot restore signal mask"));
+
 	return eax != (uint32_t)-1 && ebx == VMWARE_BDOOR_MAGIC;
 }