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authorIlya Leoshkevich <iii@linux.ibm.com>2024-10-14 22:34:21 +0200
committerRichard Henderson <richard.henderson@linaro.org>2024-10-22 13:45:03 -0700
commitbbd5630a75e70a0f1bcf04de74c94aa94a145628 (patch)
treecadae4461f9ab5e8990a545dd9d7aa4ca2af39a0 /linux-user
parente46fbc7d50289a9316fb582f4f98248bc642309e (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>
Diffstat (limited to 'linux-user')
-rw-r--r--linux-user/syscall.c4
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;
}