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[Stable-7.2.7 08/62] linux-user/hppa: clear the PSW 'N' bit when deliver
From: |
Michael Tokarev |
Subject: |
[Stable-7.2.7 08/62] linux-user/hppa: clear the PSW 'N' bit when delivering signals |
Date: |
Thu, 9 Nov 2023 16:58:36 +0300 |
From: Mikulas Patocka <mpatocka@redhat.com>
qemu-hppa may crash when delivering a signal. It can be demonstrated with
this program. Compile the program with "hppa-linux-gnu-gcc -O2 signal.c"
and run it with "qemu-hppa -one-insn-per-tb a.out". It reports that the
address of the flag is 0xb4 and it crashes when attempting to touch it.
#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
#include <signal.h>
sig_atomic_t flag;
void sig(int n)
{
printf("&flag: %p\n", &flag);
flag = 1;
}
int main(void)
{
struct sigaction sa;
struct itimerval it;
sa.sa_handler = sig;
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART;
if (sigaction(SIGALRM, &sa, NULL)) perror("sigaction"), exit(1);
it.it_interval.tv_sec = 0;
it.it_interval.tv_usec = 100;
it.it_value.tv_sec = it.it_interval.tv_sec;
it.it_value.tv_usec = it.it_interval.tv_usec;
if (setitimer(ITIMER_REAL, &it, NULL)) perror("setitimer"), exit(1);
while (1) {
}
}
The reason for the crash is that the signal handling routine doesn't clear
the 'N' flag in the PSW. If the signal interrupts a thread when the 'N'
flag is set, the flag remains set at the beginning of the signal handler
and the first instruction of the signal handler is skipped.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Helge Deller <deller@gmx.de>
Cc: qemu-stable@nongnu.org
Signed-off-by: Helge Deller <deller@gmx.de>
(cherry picked from commit 2529497cb6b298e732e8dbe5212da7925240b4f4)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
diff --git a/linux-user/hppa/signal.c b/linux-user/hppa/signal.c
index f253a15864..3a976ac693 100644
--- a/linux-user/hppa/signal.c
+++ b/linux-user/hppa/signal.c
@@ -159,6 +159,7 @@ void setup_rt_frame(int sig, struct target_sigaction *ka,
}
env->iaoq_f = haddr;
env->iaoq_b = haddr + 4;
+ env->psw_n = 0;
return;
give_sigsegv:
--
2.39.2
- [Stable-7.2.7 00/62] Patch Round-up for stable 7.2.7, freeze on 2023-11-19, Michael Tokarev, 2023/11/09
- [Stable-7.2.7 01/62] hw/ppc: Introduce functions for conversion between timebase and nanoseconds, Michael Tokarev, 2023/11/09
- [Stable-7.2.7 03/62] hw/ppc: Round up the decrementer interval when converting to ns, Michael Tokarev, 2023/11/09
- [Stable-7.2.7 02/62] host-utils: Add muldiv64_round_up, Michael Tokarev, 2023/11/09
- [Stable-7.2.7 04/62] hw/ppc: Avoid decrementer rounding errors, Michael Tokarev, 2023/11/09
- [Stable-7.2.7 08/62] linux-user/hppa: clear the PSW 'N' bit when delivering signals,
Michael Tokarev <=
- [Stable-7.2.7 09/62] linux-user/hppa: lock both words of function descriptor, Michael Tokarev, 2023/11/09
- [Stable-7.2.7 07/62] hw/ppc: Always store the decrementer value, Michael Tokarev, 2023/11/09
- [Stable-7.2.7 05/62] target/ppc: Sign-extend large decrementer to 64-bits, Michael Tokarev, 2023/11/09
- [Stable-7.2.7 22/62] target/i386: Fix and add some comments next to SSE/AVX instructions., Michael Tokarev, 2023/11/09
- [Stable-7.2.7 13/62] hw/scsi/scsi-disk: Disallow block sizes smaller than 512 [CVE-2023-42467], Michael Tokarev, 2023/11/09
- [Stable-7.2.7 06/62] target/ppc: Decrementer fix BookE semantics, Michael Tokarev, 2023/11/09
- [Stable-7.2.7 10/62] hw/cxl: Fix CFMW config memory leak, Michael Tokarev, 2023/11/09
- [Stable-7.2.7 15/62] ui/vnc: fix handling of VNC_FEATURE_XVP, Michael Tokarev, 2023/11/09
- [Stable-7.2.7 11/62] target/arm: Don't skip MTE checks for LDRT/STRT at EL0, Michael Tokarev, 2023/11/09
- [Stable-7.2.7 12/62] accel/tcg: mttcg remove false-negative halted assertion, Michael Tokarev, 2023/11/09