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| author | Alex Xu (Hello71) <alex_y_xu@yahoo.ca> | 2022-06-30 13:52:43 -0400 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2022-07-02 16:12:04 -0400 |
| commit | 63c67053a3e42e9dff788de432f82ff07d4d772a (patch) | |
| tree | 5914eb049f159c85f362e296f0822cf00c298ea3 /ldso/dynlink.c | |
| parent | a23a3da29bcca8d179d1e4de7d059639716a5c1e (diff) | |
| download | musl-63c67053a3e42e9dff788de432f82ff07d4d772a.tar.gz | |
in early stage ldso before __dls2b, call mprotect with __syscall
if LTO is enabled, gcc hoists the call to ___errno_location outside the
loop even though the access to errno is gated behind head != &ldso
because ___errno_location is marked __attribute__((const)). this causes
the program to crash because TLS is not yet initialized when called from
__dls2. this is also possible if LTO is not enabled; even though gcc 11
doesn't do it, it is still wrong to use errno here.
since the start and end are already aligned, we can simply call
__syscall instead of using global errno.
Fixes: e13a2b8953ef ("implement PT_GNU_RELRO support")
Diffstat (limited to 'ldso/dynlink.c')
| -rw-r--r-- | ldso/dynlink.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/ldso/dynlink.c b/ldso/dynlink.c index 5b9c8be4..14fdd29e 100644 --- a/ldso/dynlink.c +++ b/ldso/dynlink.c @@ -1356,12 +1356,14 @@ static void reloc_all(struct dso *p) do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2); do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3); - if (head != &ldso && p->relro_start != p->relro_end && - mprotect(laddr(p, p->relro_start), p->relro_end-p->relro_start, PROT_READ) - && errno != ENOSYS) { - error("Error relocating %s: RELRO protection failed: %m", - p->name); - if (runtime) longjmp(*rtld_fail, 1); + if (head != &ldso && p->relro_start != p->relro_end) { + long ret = __syscall(SYS_mprotect, laddr(p, p->relro_start), + p->relro_end-p->relro_start, PROT_READ); + if (ret != 0 && ret != -ENOSYS) { + error("Error relocating %s: RELRO protection failed: %m", + p->name); + if (runtime) longjmp(*rtld_fail, 1); + } } p->relocated = 1; |