[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PULL 2/3] linux-user/s390x: signal with SIGFPE on compare-and-trap
From: |
Thomas Huth |
Subject: |
[PULL 2/3] linux-user/s390x: signal with SIGFPE on compare-and-trap |
Date: |
Tue, 3 Aug 2021 16:24:54 +0200 |
From: Jonathan Albrecht <jonathan.albrecht@linux.vnet.ibm.com>
Currently when a compare-and-trap instruction is executed, qemu will
always raise a SIGILL signal. On real hardware, a SIGFPE is raised.
Change the PGM_DATA case in cpu_loop to follow the behavior in
linux kernel /arch/s390/kernel/traps.c.
* Only raise SIGILL if DXC == 0
* If DXC matches a non-simulated IEEE exception, raise SIGFPE with
correct si_code
* Raise SIGFPE with si_code == 0 for everything else
When applied on 20210705210434.45824-2-iii@linux.ibm.com, this fixes
crashes in the java jdk such as the linked bug.
Signed-off-by: Jonathan Albrecht <jonathan.albrecht@linux.vnet.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Buglink: https://bugs.launchpad.net/qemu/+bug/1920913
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/319
Message-Id: <20210709160459.4962-2-jonathan.albrecht@linux.vnet.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
linux-user/s390x/cpu_loop.c | 54 +++++++++++++++++++++++--------------
1 file changed, 34 insertions(+), 20 deletions(-)
diff --git a/linux-user/s390x/cpu_loop.c b/linux-user/s390x/cpu_loop.c
index 22f2e89c62..6a69a6dd26 100644
--- a/linux-user/s390x/cpu_loop.c
+++ b/linux-user/s390x/cpu_loop.c
@@ -25,6 +25,35 @@
/* s390x masks the fault address it reports in si_addr for SIGSEGV and SIGBUS
*/
#define S390X_FAIL_ADDR_MASK -4096LL
+static int get_pgm_data_si_code(int dxc_code)
+{
+ switch (dxc_code) {
+ /* Non-simulated IEEE exceptions */
+ case 0x80:
+ return TARGET_FPE_FLTINV;
+ case 0x40:
+ return TARGET_FPE_FLTDIV;
+ case 0x20:
+ case 0x28:
+ case 0x2c:
+ return TARGET_FPE_FLTOVF;
+ case 0x10:
+ case 0x18:
+ case 0x1c:
+ return TARGET_FPE_FLTUND;
+ case 0x08:
+ case 0x0c:
+ return TARGET_FPE_FLTRES;
+ }
+ /*
+ * Non-IEEE and simulated IEEE:
+ * Includes compare-and-trap, quantum exception, etc.
+ * Simulated IEEE are included here to match current
+ * s390x linux kernel.
+ */
+ return 0;
+}
+
void cpu_loop(CPUS390XState *env)
{
CPUState *cs = env_cpu(env);
@@ -106,29 +135,14 @@ void cpu_loop(CPUS390XState *env)
case PGM_DATA:
n = (env->fpc >> 8) & 0xff;
- if (n == 0xff) {
- /* compare-and-trap */
+ if (n == 0) {
goto do_sigill_opn;
- } else {
- /* An IEEE exception, simulated or otherwise. */
- if (n & 0x80) {
- n = TARGET_FPE_FLTINV;
- } else if (n & 0x40) {
- n = TARGET_FPE_FLTDIV;
- } else if (n & 0x20) {
- n = TARGET_FPE_FLTOVF;
- } else if (n & 0x10) {
- n = TARGET_FPE_FLTUND;
- } else if (n & 0x08) {
- n = TARGET_FPE_FLTRES;
- } else {
- /* ??? Quantum exception; BFP, DFP error. */
- goto do_sigill_opn;
- }
- sig = TARGET_SIGFPE;
- goto do_signal_pc;
}
+ sig = TARGET_SIGFPE;
+ n = get_pgm_data_si_code(n);
+ goto do_signal_pc;
+
default:
fprintf(stderr, "Unhandled program exception: %#x\n", n);
cpu_dump_state(cs, stderr, 0);
--
2.27.0