diff options
| author | Kevin Cernekee <cernekee@gmail.com> | 2011-07-24 01:19:13 -0700 |
|---|---|---|
| committer | Carmelo Amoroso <carmelo.amoroso@st.com> | 2011-07-27 09:40:24 +0200 |
| commit | a2f827c7c28c955ad49b32909452e42ccfc5e5c1 (patch) | |
| tree | 6da4313f89a4308e1c7ee1151a92ab210301d954 | |
| parent | 2d4243ce60bcd7a9f64c2ce670bc456f2c7da708 (diff) | |
ldso/mips: dlsym() incorrectly matches undefined symbols
check_match() relies on checking for (sym->st_value == 0) to see if the
symbol is undefined. This works reasonably well on most architectures,
such as ARM or i386:
$ readelf -s /lib32/libcap.so.2 | grep -E "\<malloc\>"
17: 00000000 0 FUNC GLOBAL DEFAULT UND malloc@GLIBC_2.0 (2)
However, on MIPS, libbfd puts nonzero data in the st_value field to
facilitate resetting the symbol's GOT entry if the library that defines
the symbol gets unloaded:
$ mipsel-linux-readelf -s libfoo.so | grep -E "\<malloc\>"
74: 00003140 0 FUNC GLOBAL DEFAULT UND malloc
This can cause check_match to report a false positive when examining the
external symbol reference. Consequently dlsym() will return a bad pointer
to the caller.
Use the special MIPS logic from glibc-ports-2.13 to avoid this situation.
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Carmelo Amoroso <carmelo.amoroso@st.com>
| -rw-r--r-- | ldso/ldso/dl-hash.c | 4 | ||||
| -rw-r--r-- | ldso/ldso/mips/dl-sysdep.h | 3 |
2 files changed, 7 insertions, 0 deletions
diff --git a/ldso/ldso/dl-hash.c b/ldso/ldso/dl-hash.c index 2ec883a86..9b671564f 100644 --- a/ldso/ldso/dl-hash.c +++ b/ldso/ldso/dl-hash.c @@ -188,6 +188,10 @@ check_match (const ElfW(Sym) *sym, char *strtab, const char* undef_name, int typ */ return NULL; #endif +#ifdef ARCH_SKIP_RELOC + if (ARCH_SKIP_RELOC(type_class, sym)) + return NULL; +#endif if (_dl_strcmp(strtab + sym->st_name, undef_name) != 0) return NULL; diff --git a/ldso/ldso/mips/dl-sysdep.h b/ldso/ldso/mips/dl-sysdep.h index 80c089aed..e61c6ecae 100644 --- a/ldso/ldso/mips/dl-sysdep.h +++ b/ldso/ldso/mips/dl-sysdep.h @@ -113,6 +113,9 @@ else if ((dpnt->d_tag == DT_MIPS_RLD_MAP) && (dpnt->d_un.d_ptr)) \ *(ElfW(Addr) *)(dpnt->d_un.d_ptr) = (ElfW(Addr)) debug_addr; \ } while (0) +#define ARCH_SKIP_RELOC(type_class, sym) \ + ((sym)->st_shndx == SHN_UNDEF && !((sym)->st_other & STO_MIPS_PLT)) + /* Initialization sequence for the application/library GOT. */ #define INIT_GOT(GOT_BASE,MODULE) \ do { \ |