On 5/2/23 17:37, Emilio Cota wrote:
qemu-user can hang in a multi-threaded fork. One common reason is that when creating a TB, between fork and exec we manipulate a GTree whose memory allocator (GSlice) is not fork-safe.Although POSIX does not mandate it, the system's allocator (e.g. tcmalloc, libc malloc) is probably fork-safe. Fix some of these hangs by using QTree, which uses the system's allocator regardless of the Glib version that we used at configuration time. Tested with the test program in the original bug report, i.e.: ``` void garble() { int pid = fork(); if (pid == 0) { exit(0); } else { int wstatus; waitpid(pid, &wstatus, 0); } } void supragarble(unsigned depth) { if (depth == 0) return ; std::thread a(supragarble, depth-1); std::thread b(supragarble, depth-1); garble(); a.join(); b.join(); } int main() { supragarble(10); } ``` Fixes: #285
Please use: 'Fixes: https://gitlab.com/qemu-project/qemu/-/issues/285' Also, Reported-by: Valentin David <m...@valentindavid.com>
Signed-off-by: Emilio Cota <c...@braap.org> --- accel/tcg/tb-maint.c | 17 +++++++++-------- tcg/region.c | 19 ++++++++++--------- 2 files changed, 19 insertions(+), 17 deletions(-)
Reviewed-by: Philippe Mathieu-Daudé <phi...@linaro.org>
