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| author | Christian Krinitsin <mail@krinitsin.com> | 2025-06-30 12:24:58 +0000 |
|---|---|---|
| committer | Christian Krinitsin <mail@krinitsin.com> | 2025-06-30 12:27:06 +0000 |
| commit | 33606b41d35115f887ea688b1a16f2ff85bf2fe4 (patch) | |
| tree | 406b2c7b19a087ba437c68f3dbf0b589fa1d6150 /results/scraper/launchpad-without-comments/1728116 | |
| parent | adedf8771bc4de3113041ca21bd4d0d1c0014b6a (diff) | |
| download | qemu-analysis-33606b41d35115f887ea688b1a16f2ff85bf2fe4.tar.gz qemu-analysis-33606b41d35115f887ea688b1a16f2ff85bf2fe4.zip | |
add launchpad bug reports without comments
Diffstat (limited to 'results/scraper/launchpad-without-comments/1728116')
| -rw-r--r-- | results/scraper/launchpad-without-comments/1728116 | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/results/scraper/launchpad-without-comments/1728116 b/results/scraper/launchpad-without-comments/1728116 new file mode 100644 index 000000000..fabc13509 --- /dev/null +++ b/results/scraper/launchpad-without-comments/1728116 @@ -0,0 +1,47 @@ +Empty /proc/self/auxv (linux-user) + +The userspace Linux API virtualization used to fake access to /proc/self/auxv, to provide meaningful data for the guest process. + +For newer qemu versions, this fails: The openat() is intercepted, but there's no content: /proc/self/auxv has length zero (i.e. reading from it returns 0 bytes). + +Good: + +$ x86_64-linux-user/qemu-x86_64 /usr/bin/cat /proc/self/auxv | wc -c +256 /proc/self/auxv + +Bad: + +$ x86_64-linux-user/qemu-x86_64 /usr/bin/cat /proc/self/auxv | wc -c +0 /proc/self/auxv + +This worked in 2.7.1, and fails in 2.10.1. + +This causes e.g. any procps-ng-based tool to segfault while reading from /proc/self/auxv in an endless loop (probably worth another bug report...) + +Doing a "git bisect" shows that this commit: https://github.com/qemu/qemu/commit/7c4ee5bcc introduced the problem. + +It might be a simple logic (subtraction in the wrong direction?) or sign-ness error: Adding some logging (to v2.10.1) + +diff --git a/linux-user/syscall.c b/linux-user/syscall.c +index 9b6364a..49285f9 100644 +--- a/linux-user/syscall.c ++++ b/linux-user/syscall.c +@@ -7469,6 +7469,9 @@ static int open_self_auxv(void *cpu_env, int fd) + abi_ulong len = ts->info->auxv_len; + char *ptr; + ++ gemu_log(TARGET_ABI_FMT_lu"\n", len); ++ gemu_log(TARGET_ABI_FMT_ld"\n", len); ++ + /* + * Auxiliary vector is stored in target process stack. + * read in whole auxv vector and copy it to file + +shows this output: + +$ x86_64-linux-user/qemu-x86_64 /usr/bin/cat /proc/self/auxv | wc -c +18446744073709551264 +-352 +0 + +And 352 could be the expected length. \ No newline at end of file |