Re: [PULL 0/5] Target-info update for 2026-05-12

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 14/5/26 16:16, Stefan Hajnoczi wrote:
> On Tue, May 12, 2026 at 2:32 PM Pierrick Bouvier
> <pierrick.bouvier@oss.qualcomm.com> wrote:
>>
>> The following changes since commit 5e61afe211e82a9af15a8794a0bd29bb574e953b:
>>
>>    Merge tag 'ui-pull-request' of https://gitlab.com/marcandre.lureau/qemu into staging (2026-05-11 10:49:53 -0400)
>>
>> are available in the Git repository at:
>>
>>    https://gitlab.com/p-b-o/qemu tags/pbouvier/pr/target_info-20260512
>>
>> for you to fetch changes up to 0fc2022c6331c5d5bdd9060c73d067abba3f5515:
>>
>>    target-info: replace target_info() in system-mode (2026-05-12 11:29:18 -0700)
>>
>> ----------------------------------------------------------------
>> Changes:
>> - [PATCH v6 0/5] single-binary: deduplicate target_info() (Pierrick Bouvier <pierrick.bouvier@oss.qualcomm.com>)
>>    Link: https://lore.kernel.org/qemu-devel/20260512150208.1167711-1-pierrick.bouvier@oss.qualcomm.com
>>
>> ----------------------------------------------------------------
>> Pierrick Bouvier (5):
>>        qom/object: register OBJECT and INTERFACE QOM types before main
>>        qom/object: initialize type_table in static ctor with fundamental QOM types
>>        target-info: introduce TargetInfo in QOM
>>        target-info-qom: detect target from QOM
>>        target-info: replace target_info() in system-mode
> 
> Please take a look at this CI failure:
> 
> Testing ./build-oss-fuzz/DEST_DIR/qemu-fuzz-i386-target-generic-fuzz-cirrus-vga
> ...
> AddressSanitizer:DEADLYSIGNAL
> =================================================================
> ==5334==ERROR: AddressSanitizer: SEGV on unknown address
> 0x000000000020 (pc 0x5bd0beb39ef4 bp 0x7ffe0ad764d0 sp 0x7ffe0ad764c0
> T0)
> ==5334==The signal is caused by a READ memory access.
> ==5334==Hint: address points to the zero page.
> #0 0x5bd0beb39ef4 in target_endian_mode
> /builds/qemu-project/qemu/build-oss-fuzz/../target-info.c:42:27
> #1 0x5bd0beb39ef4 in target_big_endian
> /builds/qemu-project/qemu/build-oss-fuzz/../target-info.c:47:12
> #2 0x5bd0bf4f1da1 in qtest_process_command
> /builds/qemu-project/qemu/build-oss-fuzz/../system/qtest.c:705:13
> #3 0x5bd0bf4f1da1 in qtest_process_inbuf
> /builds/qemu-project/qemu/build-oss-fuzz/../system/qtest.c:778:9
> #4 0x5bd0bf4eef54 in qtest_server_inproc_recv
> /builds/qemu-project/qemu/build-oss-fuzz/../system/qtest.c:910:9
> #5 0x5bd0bfe18f85 in qtest_sendf
> /builds/qemu-project/qemu/build-oss-fuzz/../tests/qtest/libqtest.c:715:5
> #6 0x5bd0bfe15294 in qtest_query_target_endianness
> /builds/qemu-project/qemu/build-oss-fuzz/../tests/qtest/libqtest.c:804:5
> #7 0x5bd0bfe1f2f3 in qtest_inproc_init
> /builds/qemu-project/qemu/build-oss-fuzz/../tests/qtest/libqtest.c:2043:23
> #8 0x5bd0bfe71778 in qtest_setup
> /builds/qemu-project/qemu/build-oss-fuzz/../tests/qtest/fuzz/fuzz.c:64:12
> #9 0x5bd0bfe71778 in LLVMFuzzerInitialize
> /builds/qemu-project/qemu/build-oss-fuzz/../tests/qtest/fuzz/fuzz.c:206:16
> #10 0x5bd0be9b3b56 in fuzzer::FuzzerDriver(int*, char***, int
> (*)(unsigned char const*, unsigned long)) fuzzer.o
> #11 0x5bd0be9e2166 in main


IIUC the fuzzer mode doesn't call main() -> qemu_init() but a distinct
one via LLVMFuzzerInitialize().

We'd need to squash something like:

-- >8 --
diff --git a/tests/qtest/fuzz/fuzz.c b/tests/qtest/fuzz/fuzz.c
index ca248a51a6c..90f07dcda3d 100644
--- a/tests/qtest/fuzz/fuzz.c
+++ b/tests/qtest/fuzz/fuzz.c
@@ -172,6 +172,7 @@ int LLVMFuzzerInitialize(int *argc, char ***argv, 
char ***envp)
      /* Initialize qgraph and modules */
      qos_graph_init();
      module_call_init(MODULE_INIT_FUZZ_TARGET);
+    module_call_init(MODULE_INIT_TARGET_INFO);
      module_call_init(MODULE_INIT_QOM);
      module_call_init(MODULE_INIT_LIBQOS);

---

> (/builds/qemu-project/qemu/build-oss-fuzz/DEST_DIR/qemu-fuzz-i386-target-generic-fuzz-cirrus-vga+0x46166)
> (BuildId: 845b9265a3ae1439c62fb86e3bc4973f7ea7c960)
> #12 0x7f7fef9a65b4 in __libc_start_call_main (/lib64/libc.so.6+0x35b4)
> (BuildId: abd2a4d896fed122b3f7da571746f193feeb86a1)
> #13 0x7f7fef9a6667 in __libc_start_main@GLIBC_2.2.5
> (/lib64/libc.so.6+0x3667) (BuildId:
> abd2a4d896fed122b3f7da571746f193feeb86a1)
> #14 0x5bd0be9a8f34 in _start
> (/builds/qemu-project/qemu/build-oss-fuzz/DEST_DIR/qemu-fuzz-i386-target-generic-fuzz-cirrus-vga+0xcf34)
> (BuildId: 845b9265a3ae1439c62fb86e3bc4973f7ea7c960)
> 
> https://gitlab.com/qemu-project/qemu/-/jobs/14371480130
> 
> If this issue is caused by this pull request, please send a new
> revision that solves the issue.
> 
> If this issue is not caused by this pull request, please let me know. Thanks!
> 
> Stefan
> 
>>
>>   configs/targets/aarch64-softmmu.c |  6 ++---
>>   configs/targets/arm-softmmu.c     |  6 ++---
>>   include/qemu/module.h             |  1 +
>>   include/qemu/target-info-init.h   | 53 +++++++++++++++++++++++++++++++++++++++
>>   include/qemu/target-info-qom.h    | 30 ++++++++++++++++++++++
>>   qom/object.c                      | 22 +++++-----------
>>   system/vl.c                       |  4 +++
>>   target-info-qom.c                 | 45 +++++++++++++++++++++++++++++++++
>>   target-info-stub.c                |  6 ++---
>>   9 files changed, 145 insertions(+), 28 deletions(-)
>>   create mode 100644 include/qemu/target-info-init.h
>>   create mode 100644 include/qemu/target-info-qom.h
>>
>