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* [Bug 1856837] [NEW] qemu 4.2.0 arm  segmentation fault with gcc 9.2
@ 2019-12-18 10:45 Fabian Godehardt
  2019-12-19 15:01 ` [Bug 1856837] " Peter Maydell
                   ` (5 more replies)
  0 siblings, 6 replies; 7+ messages in thread
From: Fabian Godehardt @ 2019-12-18 10:45 UTC (permalink / raw)
  To: qemu-devel

Public bug reported:

As discussed with f4bug yesterday on IRC here comes the bug description.

I'm building/configured qemu-4.2.0 on an x86_64 (gcc (Debian
6.3.0-18+deb9u1) 6.3.0 20170516) with target-list "arm-softmmu,arm-
linux-user" and debug enabled. I use the arm-linux-user variant, "qemu-
arm".

Then i'm trying to cross-compile (arm gcc) an old version of googles v8
(as i need this version of the lib for binary compatibility) which uses
qemu during build.

It worked with gcc 5.4.0 but not with 9.2.0. I also tried with 6.5.0,
7.4.0 and 8.3.0 but those are also causing the same segmentation fault.

The executed command wich breaks qemu is:

 qemu-arm /tmp/build/out/arm.release/mksnapshot.arm --log-snapshot-
positions --logfile
/tmp/build/out/arm.release/obj.host/v8_snapshot/geni/snapshot.log
--random-seed 314159265 /tmp/build/out/arm.release/obj.host/v8_snap

The printed error message is:

ARMv7=1 VFP3=1 VFP32DREGS=1 NEON=0 SUDIV=0 UNALIGNED_ACCESSES=1 MOVW_MOVT_IMMEDIATE_LOADS=0 USE_EABI_HARDFLOAT=1
qemu: uncaught target signal 11 (Segmentation fault) - core dumped

Calling qemu with gdb gives the following information:

 Thread 1 "qemu-arm" received signal SIGSEGV, Segmentation fault.
 0x0000555555d63d11 in static_code_gen_buffer ()

and

 (gdb) bt
 #0  0x0000555555d63d11 in static_code_gen_buffer ()
 #1  0x0000555555628d58 in cpu_tb_exec (itb=<optimized out>, cpu=0x555557c33930) at 
 /tmp/build/qemu/accel/tcg/cpu-exec.c:172
 #2  cpu_loop_exec_tb (tb_exit=<synthetic pointer>, last_tb=<synthetic pointer>, tb=<optimized out>, 
 cpu=0x555557c33930) at /tmp/build/qemu/accel/tcg/cpu-exec.c:618
 #3  cpu_exec (cpu=cpu@entry=0x555557c2b660) at /tmp/build/qemu/accel/tcg/cpu-exec.c:731
 #4  0x0000555555661578 in cpu_loop (env=0x555557c33930) at /tmp/build/qemu/linux-user/arm/cpu_loop.c:219
#5  0x00005555555d6d76 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at /tmp/build/qemu/linux-user/main.c:865

Calling qemu-arm with debug switch "-d in_asm,int,op_opt" shows the log
in the attached file.

Thanks for any hints!
Fabian

** Affects: qemu
     Importance: Undecided
         Status: New


** Tags: gcc9.2 segfault

** Attachment added: "Debug with in_asm,int,op_opt"
   https://bugs.launchpad.net/bugs/1856837/+attachment/5313610/+files/log-in_asm-int-op_opt

-- 
You received this bug notification because you are a member of qemu-
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https://bugs.launchpad.net/bugs/1856837

Title:
  qemu 4.2.0 arm  segmentation fault with gcc 9.2

Status in QEMU:
  New

Bug description:
  As discussed with f4bug yesterday on IRC here comes the bug
  description.

  I'm building/configured qemu-4.2.0 on an x86_64 (gcc (Debian
  6.3.0-18+deb9u1) 6.3.0 20170516) with target-list "arm-softmmu,arm-
  linux-user" and debug enabled. I use the arm-linux-user variant,
  "qemu-arm".

  Then i'm trying to cross-compile (arm gcc) an old version of googles
  v8 (as i need this version of the lib for binary compatibility) which
  uses qemu during build.

  It worked with gcc 5.4.0 but not with 9.2.0. I also tried with 6.5.0,
  7.4.0 and 8.3.0 but those are also causing the same segmentation
  fault.

  The executed command wich breaks qemu is:

   qemu-arm /tmp/build/out/arm.release/mksnapshot.arm --log-snapshot-
  positions --logfile
  /tmp/build/out/arm.release/obj.host/v8_snapshot/geni/snapshot.log
  --random-seed 314159265 /tmp/build/out/arm.release/obj.host/v8_snap

  The printed error message is:

  ARMv7=1 VFP3=1 VFP32DREGS=1 NEON=0 SUDIV=0 UNALIGNED_ACCESSES=1 MOVW_MOVT_IMMEDIATE_LOADS=0 USE_EABI_HARDFLOAT=1
  qemu: uncaught target signal 11 (Segmentation fault) - core dumped

  Calling qemu with gdb gives the following information:

   Thread 1 "qemu-arm" received signal SIGSEGV, Segmentation fault.
   0x0000555555d63d11 in static_code_gen_buffer ()

  and

   (gdb) bt
   #0  0x0000555555d63d11 in static_code_gen_buffer ()
   #1  0x0000555555628d58 in cpu_tb_exec (itb=<optimized out>, cpu=0x555557c33930) at 
   /tmp/build/qemu/accel/tcg/cpu-exec.c:172
   #2  cpu_loop_exec_tb (tb_exit=<synthetic pointer>, last_tb=<synthetic pointer>, tb=<optimized out>, 
   cpu=0x555557c33930) at /tmp/build/qemu/accel/tcg/cpu-exec.c:618
   #3  cpu_exec (cpu=cpu@entry=0x555557c2b660) at /tmp/build/qemu/accel/tcg/cpu-exec.c:731
   #4  0x0000555555661578 in cpu_loop (env=0x555557c33930) at /tmp/build/qemu/linux-user/arm/cpu_loop.c:219
  #5  0x00005555555d6d76 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at /tmp/build/qemu/linux-user/main.c:865

  Calling qemu-arm with debug switch "-d in_asm,int,op_opt" shows the
  log in the attached file.

  Thanks for any hints!
  Fabian

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1856837/+subscriptions


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [Bug 1856837] Re: qemu 4.2.0 arm  segmentation fault with gcc 9.2
  2019-12-18 10:45 [Bug 1856837] [NEW] qemu 4.2.0 arm segmentation fault with gcc 9.2 Fabian Godehardt
@ 2019-12-19 15:01 ` Peter Maydell
  2020-01-06  7:39 ` Fabian Godehardt
                   ` (4 subsequent siblings)
  5 siblings, 0 replies; 7+ messages in thread
From: Peter Maydell @ 2019-12-19 15:01 UTC (permalink / raw)
  To: qemu-devel

Can you provide a repro case (attach binary/etc to the bug) so we can
investigate?

Note that QEMU will produce that segfault message both for bugs in QEMU
(where it unexpectedly segfaults) but also for bugs in the guest binary
itself where we're correctly emulating "guest did something causing a
segfault".


** Tags added: arm

-- 
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https://bugs.launchpad.net/bugs/1856837

Title:
  qemu 4.2.0 arm  segmentation fault with gcc 9.2

Status in QEMU:
  New

Bug description:
  As discussed with f4bug yesterday on IRC here comes the bug
  description.

  I'm building/configured qemu-4.2.0 on an x86_64 (gcc (Debian
  6.3.0-18+deb9u1) 6.3.0 20170516) with target-list "arm-softmmu,arm-
  linux-user" and debug enabled. I use the arm-linux-user variant,
  "qemu-arm".

  Then i'm trying to cross-compile (arm gcc) an old version of googles
  v8 (as i need this version of the lib for binary compatibility) which
  uses qemu during build.

  It worked with gcc 5.4.0 but not with 9.2.0. I also tried with 6.5.0,
  7.4.0 and 8.3.0 but those are also causing the same segmentation
  fault.

  The executed command wich breaks qemu is:

   qemu-arm /tmp/build/out/arm.release/mksnapshot.arm --log-snapshot-
  positions --logfile
  /tmp/build/out/arm.release/obj.host/v8_snapshot/geni/snapshot.log
  --random-seed 314159265 /tmp/build/out/arm.release/obj.host/v8_snap

  The printed error message is:

  ARMv7=1 VFP3=1 VFP32DREGS=1 NEON=0 SUDIV=0 UNALIGNED_ACCESSES=1 MOVW_MOVT_IMMEDIATE_LOADS=0 USE_EABI_HARDFLOAT=1
  qemu: uncaught target signal 11 (Segmentation fault) - core dumped

  Calling qemu with gdb gives the following information:

   Thread 1 "qemu-arm" received signal SIGSEGV, Segmentation fault.
   0x0000555555d63d11 in static_code_gen_buffer ()

  and

   (gdb) bt
   #0  0x0000555555d63d11 in static_code_gen_buffer ()
   #1  0x0000555555628d58 in cpu_tb_exec (itb=<optimized out>, cpu=0x555557c33930) at 
   /tmp/build/qemu/accel/tcg/cpu-exec.c:172
   #2  cpu_loop_exec_tb (tb_exit=<synthetic pointer>, last_tb=<synthetic pointer>, tb=<optimized out>, 
   cpu=0x555557c33930) at /tmp/build/qemu/accel/tcg/cpu-exec.c:618
   #3  cpu_exec (cpu=cpu@entry=0x555557c2b660) at /tmp/build/qemu/accel/tcg/cpu-exec.c:731
   #4  0x0000555555661578 in cpu_loop (env=0x555557c33930) at /tmp/build/qemu/linux-user/arm/cpu_loop.c:219
  #5  0x00005555555d6d76 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at /tmp/build/qemu/linux-user/main.c:865

  Calling qemu-arm with debug switch "-d in_asm,int,op_opt" shows the
  log in the attached file.

  Thanks for any hints!
  Fabian

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1856837/+subscriptions


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [Bug 1856837] Re: qemu 4.2.0 arm  segmentation fault with gcc 9.2
  2019-12-18 10:45 [Bug 1856837] [NEW] qemu 4.2.0 arm segmentation fault with gcc 9.2 Fabian Godehardt
  2019-12-19 15:01 ` [Bug 1856837] " Peter Maydell
@ 2020-01-06  7:39 ` Fabian Godehardt
  2020-01-20 15:26 ` Peter Maydell
                   ` (3 subsequent siblings)
  5 siblings, 0 replies; 7+ messages in thread
From: Fabian Godehardt @ 2020-01-06  7:39 UTC (permalink / raw)
  To: qemu-devel

Sorry for the delay. I added the sysroot, the binary and the files causing the segfault.
Please let me know if there is something missing.

I used the following commands to let it run:

export LD_LIBRARY_PATH=/opt/qemu-test/test1/lib
/opt/qemu-test/test1/bin/qemu-arm "/opt/qemu-test/test1/files/mksnapshot.arm" --log-snapshot-positions --logfile "/tmp/snapshot.log" --random-seed 314159265 "/tmp/snapshot.cc"


Thanks again!
Fabian

** Attachment added: "Tarball containing sysroot, qemu binary and files"
   https://bugs.launchpad.net/qemu/+bug/1856837/+attachment/5317851/+files/qemu-segfault-v8.tar.xz

-- 
You received this bug notification because you are a member of qemu-
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https://bugs.launchpad.net/bugs/1856837

Title:
  qemu 4.2.0 arm  segmentation fault with gcc 9.2

Status in QEMU:
  New

Bug description:
  As discussed with f4bug yesterday on IRC here comes the bug
  description.

  I'm building/configured qemu-4.2.0 on an x86_64 (gcc (Debian
  6.3.0-18+deb9u1) 6.3.0 20170516) with target-list "arm-softmmu,arm-
  linux-user" and debug enabled. I use the arm-linux-user variant,
  "qemu-arm".

  Then i'm trying to cross-compile (arm gcc) an old version of googles
  v8 (as i need this version of the lib for binary compatibility) which
  uses qemu during build.

  It worked with gcc 5.4.0 but not with 9.2.0. I also tried with 6.5.0,
  7.4.0 and 8.3.0 but those are also causing the same segmentation
  fault.

  The executed command wich breaks qemu is:

   qemu-arm /tmp/build/out/arm.release/mksnapshot.arm --log-snapshot-
  positions --logfile
  /tmp/build/out/arm.release/obj.host/v8_snapshot/geni/snapshot.log
  --random-seed 314159265 /tmp/build/out/arm.release/obj.host/v8_snap

  The printed error message is:

  ARMv7=1 VFP3=1 VFP32DREGS=1 NEON=0 SUDIV=0 UNALIGNED_ACCESSES=1 MOVW_MOVT_IMMEDIATE_LOADS=0 USE_EABI_HARDFLOAT=1
  qemu: uncaught target signal 11 (Segmentation fault) - core dumped

  Calling qemu with gdb gives the following information:

   Thread 1 "qemu-arm" received signal SIGSEGV, Segmentation fault.
   0x0000555555d63d11 in static_code_gen_buffer ()

  and

   (gdb) bt
   #0  0x0000555555d63d11 in static_code_gen_buffer ()
   #1  0x0000555555628d58 in cpu_tb_exec (itb=<optimized out>, cpu=0x555557c33930) at 
   /tmp/build/qemu/accel/tcg/cpu-exec.c:172
   #2  cpu_loop_exec_tb (tb_exit=<synthetic pointer>, last_tb=<synthetic pointer>, tb=<optimized out>, 
   cpu=0x555557c33930) at /tmp/build/qemu/accel/tcg/cpu-exec.c:618
   #3  cpu_exec (cpu=cpu@entry=0x555557c2b660) at /tmp/build/qemu/accel/tcg/cpu-exec.c:731
   #4  0x0000555555661578 in cpu_loop (env=0x555557c33930) at /tmp/build/qemu/linux-user/arm/cpu_loop.c:219
  #5  0x00005555555d6d76 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at /tmp/build/qemu/linux-user/main.c:865

  Calling qemu-arm with debug switch "-d in_asm,int,op_opt" shows the
  log in the attached file.

  Thanks for any hints!
  Fabian

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1856837/+subscriptions


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [Bug 1856837] Re: qemu 4.2.0 arm  segmentation fault with gcc 9.2
  2019-12-18 10:45 [Bug 1856837] [NEW] qemu 4.2.0 arm segmentation fault with gcc 9.2 Fabian Godehardt
  2019-12-19 15:01 ` [Bug 1856837] " Peter Maydell
  2020-01-06  7:39 ` Fabian Godehardt
@ 2020-01-20 15:26 ` Peter Maydell
  2020-01-28  7:28 ` Fabian Godehardt
                   ` (2 subsequent siblings)
  5 siblings, 0 replies; 7+ messages in thread
From: Peter Maydell @ 2020-01-20 15:26 UTC (permalink / raw)
  To: qemu-devel

At the point of the segfault, QEMU is correctly delivering a segfault to
the guest because it has attempted to dereference a NULL pointer. You
can see this if you run QEMU with the '-g 1234' option and connect an
arm-aware gdb to it:

(gdb) disas $pc-32,$pc+32
Dump of assembler code from 0x2bf24c to 0x2bf28c:
   0x002bf24c:  ldr     r4, [r0, #296]  ; 0x128
   0x002bf250:  mov     r6, r1
   0x002bf254:  add     r8, r0, #40     ; 0x28
   0x002bf258:  mov     r5, #0
   0x002bf25c:  b       0x2bf268
   0x002bf260:  cmp     r5, r6
   0x002bf264:  bge     0x2bf2d4
   0x002bf268:  mov     r12, r4
=> 0x002bf26c:  ldr     r4, [r4]
   0x002bf270:  ldr     r3, [r12, #12]
   0x002bf274:  tst     r3, #512        ; 0x200
   0x002bf278:  bne     0x2bf2c0
   0x002bf27c:  tst     r3, #1024       ; 0x400
   0x002bf280:  ubfx    r1, r3, #11, #1
   0x002bf284:  bne     0x2bf2c0
   0x002bf288:  tst     r3, #2048       ; 0x800
End of assembler dump.
(gdb) print /x $r4
$3 = 0x0

It looks like this is in the middle of somebody's garbage collector (the
elf symbol is _ZN2v88internal10PagedSpace14AdvanceSweeperEi).

The next step would be to find out what was going on in the run-up to
that that resulted in the NULL pointer. That's a bit of guest-level
debugging work that would be much easier with the source code. If you
can debug where something unexpected happens to the guest that would
probably help -- this is likely to be a much longer piece of debugging
than I'm afraid I have time to do.

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1856837

Title:
  qemu 4.2.0 arm  segmentation fault with gcc 9.2

Status in QEMU:
  New

Bug description:
  As discussed with f4bug yesterday on IRC here comes the bug
  description.

  I'm building/configured qemu-4.2.0 on an x86_64 (gcc (Debian
  6.3.0-18+deb9u1) 6.3.0 20170516) with target-list "arm-softmmu,arm-
  linux-user" and debug enabled. I use the arm-linux-user variant,
  "qemu-arm".

  Then i'm trying to cross-compile (arm gcc) an old version of googles
  v8 (as i need this version of the lib for binary compatibility) which
  uses qemu during build.

  It worked with gcc 5.4.0 but not with 9.2.0. I also tried with 6.5.0,
  7.4.0 and 8.3.0 but those are also causing the same segmentation
  fault.

  The executed command wich breaks qemu is:

   qemu-arm /tmp/build/out/arm.release/mksnapshot.arm --log-snapshot-
  positions --logfile
  /tmp/build/out/arm.release/obj.host/v8_snapshot/geni/snapshot.log
  --random-seed 314159265 /tmp/build/out/arm.release/obj.host/v8_snap

  The printed error message is:

  ARMv7=1 VFP3=1 VFP32DREGS=1 NEON=0 SUDIV=0 UNALIGNED_ACCESSES=1 MOVW_MOVT_IMMEDIATE_LOADS=0 USE_EABI_HARDFLOAT=1
  qemu: uncaught target signal 11 (Segmentation fault) - core dumped

  Calling qemu with gdb gives the following information:

   Thread 1 "qemu-arm" received signal SIGSEGV, Segmentation fault.
   0x0000555555d63d11 in static_code_gen_buffer ()

  and

   (gdb) bt
   #0  0x0000555555d63d11 in static_code_gen_buffer ()
   #1  0x0000555555628d58 in cpu_tb_exec (itb=<optimized out>, cpu=0x555557c33930) at 
   /tmp/build/qemu/accel/tcg/cpu-exec.c:172
   #2  cpu_loop_exec_tb (tb_exit=<synthetic pointer>, last_tb=<synthetic pointer>, tb=<optimized out>, 
   cpu=0x555557c33930) at /tmp/build/qemu/accel/tcg/cpu-exec.c:618
   #3  cpu_exec (cpu=cpu@entry=0x555557c2b660) at /tmp/build/qemu/accel/tcg/cpu-exec.c:731
   #4  0x0000555555661578 in cpu_loop (env=0x555557c33930) at /tmp/build/qemu/linux-user/arm/cpu_loop.c:219
  #5  0x00005555555d6d76 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at /tmp/build/qemu/linux-user/main.c:865

  Calling qemu-arm with debug switch "-d in_asm,int,op_opt" shows the
  log in the attached file.

  Thanks for any hints!
  Fabian

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1856837/+subscriptions


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [Bug 1856837] Re: qemu 4.2.0 arm  segmentation fault with gcc 9.2
  2019-12-18 10:45 [Bug 1856837] [NEW] qemu 4.2.0 arm segmentation fault with gcc 9.2 Fabian Godehardt
                   ` (2 preceding siblings ...)
  2020-01-20 15:26 ` Peter Maydell
@ 2020-01-28  7:28 ` Fabian Godehardt
  2021-05-02 18:15 ` Thomas Huth
  2021-07-02  4:17 ` Launchpad Bug Tracker
  5 siblings, 0 replies; 7+ messages in thread
From: Fabian Godehardt @ 2020-01-28  7:28 UTC (permalink / raw)
  To: qemu-devel

Thanks, this helps a lot! We will now check the code again and see what
causes the behaviour.

Fabian

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1856837

Title:
  qemu 4.2.0 arm  segmentation fault with gcc 9.2

Status in QEMU:
  New

Bug description:
  As discussed with f4bug yesterday on IRC here comes the bug
  description.

  I'm building/configured qemu-4.2.0 on an x86_64 (gcc (Debian
  6.3.0-18+deb9u1) 6.3.0 20170516) with target-list "arm-softmmu,arm-
  linux-user" and debug enabled. I use the arm-linux-user variant,
  "qemu-arm".

  Then i'm trying to cross-compile (arm gcc) an old version of googles
  v8 (as i need this version of the lib for binary compatibility) which
  uses qemu during build.

  It worked with gcc 5.4.0 but not with 9.2.0. I also tried with 6.5.0,
  7.4.0 and 8.3.0 but those are also causing the same segmentation
  fault.

  The executed command wich breaks qemu is:

   qemu-arm /tmp/build/out/arm.release/mksnapshot.arm --log-snapshot-
  positions --logfile
  /tmp/build/out/arm.release/obj.host/v8_snapshot/geni/snapshot.log
  --random-seed 314159265 /tmp/build/out/arm.release/obj.host/v8_snap

  The printed error message is:

  ARMv7=1 VFP3=1 VFP32DREGS=1 NEON=0 SUDIV=0 UNALIGNED_ACCESSES=1 MOVW_MOVT_IMMEDIATE_LOADS=0 USE_EABI_HARDFLOAT=1
  qemu: uncaught target signal 11 (Segmentation fault) - core dumped

  Calling qemu with gdb gives the following information:

   Thread 1 "qemu-arm" received signal SIGSEGV, Segmentation fault.
   0x0000555555d63d11 in static_code_gen_buffer ()

  and

   (gdb) bt
   #0  0x0000555555d63d11 in static_code_gen_buffer ()
   #1  0x0000555555628d58 in cpu_tb_exec (itb=<optimized out>, cpu=0x555557c33930) at 
   /tmp/build/qemu/accel/tcg/cpu-exec.c:172
   #2  cpu_loop_exec_tb (tb_exit=<synthetic pointer>, last_tb=<synthetic pointer>, tb=<optimized out>, 
   cpu=0x555557c33930) at /tmp/build/qemu/accel/tcg/cpu-exec.c:618
   #3  cpu_exec (cpu=cpu@entry=0x555557c2b660) at /tmp/build/qemu/accel/tcg/cpu-exec.c:731
   #4  0x0000555555661578 in cpu_loop (env=0x555557c33930) at /tmp/build/qemu/linux-user/arm/cpu_loop.c:219
  #5  0x00005555555d6d76 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at /tmp/build/qemu/linux-user/main.c:865

  Calling qemu-arm with debug switch "-d in_asm,int,op_opt" shows the
  log in the attached file.

  Thanks for any hints!
  Fabian

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1856837/+subscriptions


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [Bug 1856837] Re: qemu 4.2.0 arm  segmentation fault with gcc 9.2
  2019-12-18 10:45 [Bug 1856837] [NEW] qemu 4.2.0 arm segmentation fault with gcc 9.2 Fabian Godehardt
                   ` (3 preceding siblings ...)
  2020-01-28  7:28 ` Fabian Godehardt
@ 2021-05-02 18:15 ` Thomas Huth
  2021-07-02  4:17 ` Launchpad Bug Tracker
  5 siblings, 0 replies; 7+ messages in thread
From: Thomas Huth @ 2021-05-02 18:15 UTC (permalink / raw)
  To: qemu-devel

The QEMU project is currently considering to move its bug tracking to
another system. For this we need to know which bugs are still valid
and which could be closed already. Thus we are setting older bugs to
"Incomplete" now.

If you still think this bug report here is valid, then please switch
the state back to "New" within the next 60 days, otherwise this report
will be marked as "Expired". Or please mark it as "Fix Released" if
the problem has been solved with a newer version of QEMU already.

Thank you and sorry for the inconvenience.


** Changed in: qemu
       Status: New => Incomplete

-- 
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https://bugs.launchpad.net/bugs/1856837

Title:
  qemu 4.2.0 arm  segmentation fault with gcc 9.2

Status in QEMU:
  Incomplete

Bug description:
  As discussed with f4bug yesterday on IRC here comes the bug
  description.

  I'm building/configured qemu-4.2.0 on an x86_64 (gcc (Debian
  6.3.0-18+deb9u1) 6.3.0 20170516) with target-list "arm-softmmu,arm-
  linux-user" and debug enabled. I use the arm-linux-user variant,
  "qemu-arm".

  Then i'm trying to cross-compile (arm gcc) an old version of googles
  v8 (as i need this version of the lib for binary compatibility) which
  uses qemu during build.

  It worked with gcc 5.4.0 but not with 9.2.0. I also tried with 6.5.0,
  7.4.0 and 8.3.0 but those are also causing the same segmentation
  fault.

  The executed command wich breaks qemu is:

   qemu-arm /tmp/build/out/arm.release/mksnapshot.arm --log-snapshot-
  positions --logfile
  /tmp/build/out/arm.release/obj.host/v8_snapshot/geni/snapshot.log
  --random-seed 314159265 /tmp/build/out/arm.release/obj.host/v8_snap

  The printed error message is:

  ARMv7=1 VFP3=1 VFP32DREGS=1 NEON=0 SUDIV=0 UNALIGNED_ACCESSES=1 MOVW_MOVT_IMMEDIATE_LOADS=0 USE_EABI_HARDFLOAT=1
  qemu: uncaught target signal 11 (Segmentation fault) - core dumped

  Calling qemu with gdb gives the following information:

   Thread 1 "qemu-arm" received signal SIGSEGV, Segmentation fault.
   0x0000555555d63d11 in static_code_gen_buffer ()

  and

   (gdb) bt
   #0  0x0000555555d63d11 in static_code_gen_buffer ()
   #1  0x0000555555628d58 in cpu_tb_exec (itb=<optimized out>, cpu=0x555557c33930) at 
   /tmp/build/qemu/accel/tcg/cpu-exec.c:172
   #2  cpu_loop_exec_tb (tb_exit=<synthetic pointer>, last_tb=<synthetic pointer>, tb=<optimized out>, 
   cpu=0x555557c33930) at /tmp/build/qemu/accel/tcg/cpu-exec.c:618
   #3  cpu_exec (cpu=cpu@entry=0x555557c2b660) at /tmp/build/qemu/accel/tcg/cpu-exec.c:731
   #4  0x0000555555661578 in cpu_loop (env=0x555557c33930) at /tmp/build/qemu/linux-user/arm/cpu_loop.c:219
  #5  0x00005555555d6d76 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at /tmp/build/qemu/linux-user/main.c:865

  Calling qemu-arm with debug switch "-d in_asm,int,op_opt" shows the
  log in the attached file.

  Thanks for any hints!
  Fabian

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1856837/+subscriptions


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [Bug 1856837] Re: qemu 4.2.0 arm  segmentation fault with gcc 9.2
  2019-12-18 10:45 [Bug 1856837] [NEW] qemu 4.2.0 arm segmentation fault with gcc 9.2 Fabian Godehardt
                   ` (4 preceding siblings ...)
  2021-05-02 18:15 ` Thomas Huth
@ 2021-07-02  4:17 ` Launchpad Bug Tracker
  5 siblings, 0 replies; 7+ messages in thread
From: Launchpad Bug Tracker @ 2021-07-02  4:17 UTC (permalink / raw)
  To: qemu-devel

[Expired for QEMU because there has been no activity for 60 days.]

** Changed in: qemu
       Status: Incomplete => Expired

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https://bugs.launchpad.net/bugs/1856837

Title:
  qemu 4.2.0 arm  segmentation fault with gcc 9.2

Status in QEMU:
  Expired

Bug description:
  As discussed with f4bug yesterday on IRC here comes the bug
  description.

  I'm building/configured qemu-4.2.0 on an x86_64 (gcc (Debian
  6.3.0-18+deb9u1) 6.3.0 20170516) with target-list "arm-softmmu,arm-
  linux-user" and debug enabled. I use the arm-linux-user variant,
  "qemu-arm".

  Then i'm trying to cross-compile (arm gcc) an old version of googles
  v8 (as i need this version of the lib for binary compatibility) which
  uses qemu during build.

  It worked with gcc 5.4.0 but not with 9.2.0. I also tried with 6.5.0,
  7.4.0 and 8.3.0 but those are also causing the same segmentation
  fault.

  The executed command wich breaks qemu is:

   qemu-arm /tmp/build/out/arm.release/mksnapshot.arm --log-snapshot-
  positions --logfile
  /tmp/build/out/arm.release/obj.host/v8_snapshot/geni/snapshot.log
  --random-seed 314159265 /tmp/build/out/arm.release/obj.host/v8_snap

  The printed error message is:

  ARMv7=1 VFP3=1 VFP32DREGS=1 NEON=0 SUDIV=0 UNALIGNED_ACCESSES=1 MOVW_MOVT_IMMEDIATE_LOADS=0 USE_EABI_HARDFLOAT=1
  qemu: uncaught target signal 11 (Segmentation fault) - core dumped

  Calling qemu with gdb gives the following information:

   Thread 1 "qemu-arm" received signal SIGSEGV, Segmentation fault.
   0x0000555555d63d11 in static_code_gen_buffer ()

  and

   (gdb) bt
   #0  0x0000555555d63d11 in static_code_gen_buffer ()
   #1  0x0000555555628d58 in cpu_tb_exec (itb=<optimized out>, cpu=0x555557c33930) at 
   /tmp/build/qemu/accel/tcg/cpu-exec.c:172
   #2  cpu_loop_exec_tb (tb_exit=<synthetic pointer>, last_tb=<synthetic pointer>, tb=<optimized out>, 
   cpu=0x555557c33930) at /tmp/build/qemu/accel/tcg/cpu-exec.c:618
   #3  cpu_exec (cpu=cpu@entry=0x555557c2b660) at /tmp/build/qemu/accel/tcg/cpu-exec.c:731
   #4  0x0000555555661578 in cpu_loop (env=0x555557c33930) at /tmp/build/qemu/linux-user/arm/cpu_loop.c:219
  #5  0x00005555555d6d76 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at /tmp/build/qemu/linux-user/main.c:865

  Calling qemu-arm with debug switch "-d in_asm,int,op_opt" shows the
  log in the attached file.

  Thanks for any hints!
  Fabian

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1856837/+subscriptions


^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2021-07-02  4:39 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-12-18 10:45 [Bug 1856837] [NEW] qemu 4.2.0 arm segmentation fault with gcc 9.2 Fabian Godehardt
2019-12-19 15:01 ` [Bug 1856837] " Peter Maydell
2020-01-06  7:39 ` Fabian Godehardt
2020-01-20 15:26 ` Peter Maydell
2020-01-28  7:28 ` Fabian Godehardt
2021-05-02 18:15 ` Thomas Huth
2021-07-02  4:17 ` Launchpad Bug Tracker

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