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Diffstat (limited to 'results/classifier/zero-shot-user-mode/output/instruction/1729')
| -rw-r--r-- | results/classifier/zero-shot-user-mode/output/instruction/1729 | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/results/classifier/zero-shot-user-mode/output/instruction/1729 b/results/classifier/zero-shot-user-mode/output/instruction/1729 new file mode 100644 index 000000000..bed8862c9 --- /dev/null +++ b/results/classifier/zero-shot-user-mode/output/instruction/1729 @@ -0,0 +1,53 @@ +instruction: 0.526 +runtime: 0.308 +syscall: 0.166 + + + +mremap fails with EFAULT if address range overlaps with stack guard +Description of problem: +When running 32-bit user-static on 64-bit host, `mremap` behave differently from the kernel. This difference let programs that call `pthread_getattr_np` on musl-libc to run into a loop on repeated calling `mremap`. + +https://git.musl-libc.org/cgit/musl/plain/src/thread/pthread_getattr_np.c + +``` c + while (mremap(p-l-PAGE_SIZE, PAGE_SIZE, 2*PAGE_SIZE, 0)==MAP_FAILED && errno==ENOMEM) + l += PAGE_SIZE; +``` +Steps to reproduce: +Compile the following program against musl-libc arm 32-bit, and run it in qemu-user-static on x86_64 host. + +``` c +#define _GNU_SOURCE +#include <pthread.h> + +int main(int argc, char *argv[]) { + pthread_attr_t attr; + return pthread_getattr_np(pthread_self(), &attr); +} +``` + +For example, on x86_64 fedora 38 with podman and qemu-user-static installed, we can reproduce this with alpine container: + +``` +$ podman run --rm -it --arch arm/v7 docker.io/library/alpine:latest + +/ # apk add alpine-sdk + +...... + +/ # cat test.c +#define _GNU_SOURCE +#include <pthread.h> + +int main(int argc, char *argv[]) { + pthread_attr_t attr; + return pthread_getattr_np(pthread_self(), &attr); +} + +/ # gcc test.c + +/ # ./a.out +``` +Additional information: +Original thread on musl mail list where this was initially reported: https://www.openwall.com/lists/musl/2017/06/15/9 |