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>

0 files changed, 0 insertions, 0 deletions