diff options
| author | Ilya Leoshkevich <iii@linux.ibm.com> | 2023-02-14 15:08:27 +0100 |
|---|---|---|
| committer | Richard Henderson <richard.henderson@linaro.org> | 2023-02-21 08:44:13 -1000 |
| commit | df8a688032280ecd07ace7c6fbc70f5650cca9af (patch) | |
| tree | 1bd5deeda135d8a288d0c822e6619425831b120f | |
| parent | 7de0816f699553514016f52a76e26d1c2ae14034 (diff) | |
| download | qemu-df8a688032280ecd07ace7c6fbc70f5650cca9af.zip qemu-df8a688032280ecd07ace7c6fbc70f5650cca9af.tar.gz qemu-df8a688032280ecd07ace7c6fbc70f5650cca9af.tar.bz2 | |
cpus: Make {start,end}_exclusive() recursive
Currently dying to one of the core_dump_signal()s deadlocks, because
dump_core_and_abort() calls start_exclusive() two times: first via
stop_all_tasks(), and then via preexit_cleanup() ->
qemu_plugin_user_exit().
There are a number of ways to solve this: resume after dumping core;
check cpu_in_exclusive_context() in qemu_plugin_user_exit(); or make
{start,end}_exclusive() recursive. Pick the last option, since it's
the most straightforward one.
Fixes: da91c1920242 ("linux-user: Clean up when exiting due to a signal")
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20230214140829.45392-3-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
| -rw-r--r-- | cpus-common.c | 12 | ||||
| -rw-r--r-- | include/hw/core/cpu.h | 4 |
2 files changed, 12 insertions, 4 deletions
diff --git a/cpus-common.c b/cpus-common.c index 793364d..39f355d 100644 --- a/cpus-common.c +++ b/cpus-common.c @@ -192,6 +192,11 @@ void start_exclusive(void) CPUState *other_cpu; int running_cpus; + if (current_cpu->exclusive_context_count) { + current_cpu->exclusive_context_count++; + return; + } + qemu_mutex_lock(&qemu_cpu_list_lock); exclusive_idle(); @@ -219,13 +224,16 @@ void start_exclusive(void) */ qemu_mutex_unlock(&qemu_cpu_list_lock); - current_cpu->in_exclusive_context = true; + current_cpu->exclusive_context_count = 1; } /* Finish an exclusive operation. */ void end_exclusive(void) { - current_cpu->in_exclusive_context = false; + current_cpu->exclusive_context_count--; + if (current_cpu->exclusive_context_count) { + return; + } qemu_mutex_lock(&qemu_cpu_list_lock); qatomic_set(&pending_cpus, 0); diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h index 2417597..671f041 100644 --- a/include/hw/core/cpu.h +++ b/include/hw/core/cpu.h @@ -349,7 +349,7 @@ struct CPUState { bool unplug; bool crash_occurred; bool exit_request; - bool in_exclusive_context; + int exclusive_context_count; uint32_t cflags_next_tb; /* updates protected by BQL */ uint32_t interrupt_request; @@ -758,7 +758,7 @@ void async_safe_run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data */ static inline bool cpu_in_exclusive_context(const CPUState *cpu) { - return cpu->in_exclusive_context; + return cpu->exclusive_context_count; } /** |