diff options
| author | Ilya Leoshkevich <iii@linux.ibm.com> | 2024-10-14 22:34:21 +0200 |
|---|---|---|
| committer | Richard Henderson <richard.henderson@linaro.org> | 2024-10-22 13:45:03 -0700 |
| commit | bbd5630a75e70a0f1bcf04de74c94aa94a145628 (patch) | |
| tree | cadae4461f9ab5e8990a545dd9d7aa4ca2af39a0 | |
| parent | e46fbc7d50289a9316fb582f4f98248bc642309e (diff) | |
linux-user: Emulate /proc/self/maps under mmap_lock
If one thread modifies the mappings and another thread prints them,
a situation may occur that the printer thread sees a guest mapping
without a corresponding host mapping, leading to a crash in
open_self_maps_2().
Cc: qemu-stable@nongnu.org
Fixes: 7b7a3366e142 ("linux-user: Use walk_memory_regions for open_self_maps")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20241014203441.387560-1-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
| -rw-r--r-- | linux-user/syscall.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 1354e75694..dd2ec0712b 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -8151,17 +8151,19 @@ static int open_self_maps_1(CPUArchState *env, int fd, bool smaps) { struct open_self_maps_data d = { .ts = get_task_state(env_cpu(env)), - .host_maps = read_self_maps(), .fd = fd, .smaps = smaps }; + mmap_lock(); + d.host_maps = read_self_maps(); if (d.host_maps) { walk_memory_regions(&d, open_self_maps_2); free_self_maps(d.host_maps); } else { walk_memory_regions(&d, open_self_maps_3); } + mmap_unlock(); return 0; } |