| Message ID | 20191217214728.2886-8-adhemerval.zanella@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [v2,01/16] linux: Fix vDSO macros build with time64 interfaces | expand |
On 18/12/19 3:17 am, Adhemerval Zanella wrote: > Changes from previous version: > > - The tests were removed and instead I will use the ones proposed > by Florian's patch 'elf: Add tests for working RELRO protection' > [1]. I also plan to send additional coverage for '.data.rel.ro' > which trigger failures for the static case on both partial and > full relro which is fixed by this patch once the patch is > upstream. > > -- > > The code is similar to the one at elf/dl-reloc.c, where it checks for > the l_relro_size from the link_map (obtained from PT_GNU_RELRO header > from program headers) and calls_dl_protected_relro. > > Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu, > aarch64-linux-gnu, s390x-linux-gnu, and sparc64-linux-gnu. I also > check with --enable-static pie on x86_64-linux-gnu, i686-linux-gnu, > and aarch64-linux-gnu which seems the only architectures where > static PIE is actually working (as per 9d7a3741c9e, on > arm-linux-gnueabihf, powerpc64{le}-linux-gnu, and s390x-linux-gnu > I am seeing runtime issues not related to my patch). > > [1] https://sourceware.org/ml/libc-alpha/2019-10/msg00059.html > --- > elf/dl-support.c | 18 ++++++++++++++---- > 1 file changed, 14 insertions(+), 4 deletions(-) > OK. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
diff --git a/elf/dl-support.c b/elf/dl-support.c index 5526d5ee6e..b2b1b12f6f 100644 --- a/elf/dl-support.c +++ b/elf/dl-support.c @@ -367,14 +367,24 @@ _dl_non_dynamic_init (void) if (_dl_platform != NULL) _dl_platformlen = strlen (_dl_platform); - /* Scan for a program header telling us the stack is nonexecutable. */ if (_dl_phdr != NULL) - for (uint_fast16_t i = 0; i < _dl_phnum; ++i) - if (_dl_phdr[i].p_type == PT_GNU_STACK) + for (const ElfW(Phdr) *ph = _dl_phdr; ph < &_dl_phdr[_dl_phnum]; ++ph) + switch (ph->p_type) { - _dl_stack_flags = _dl_phdr[i].p_flags; + /* Check if the stack is nonexecutable. */ + case PT_GNU_STACK: + _dl_stack_flags = ph->p_flags; + break; + + case PT_GNU_RELRO: + _dl_main_map.l_relro_addr = ph->p_vaddr; + _dl_main_map.l_relro_size = ph->p_memsz; break; } + + /* Setup relro on the binary itself. */ + if (_dl_main_map.l_relro_size != 0) + _dl_protect_relro (&_dl_main_map); } #ifdef DL_SYSINFO_IMPLEMENTATION
Changes from previous version: - The tests were removed and instead I will use the ones proposed by Florian's patch 'elf: Add tests for working RELRO protection' [1]. I also plan to send additional coverage for '.data.rel.ro' which trigger failures for the static case on both partial and full relro which is fixed by this patch once the patch is upstream. -- The code is similar to the one at elf/dl-reloc.c, where it checks for the l_relro_size from the link_map (obtained from PT_GNU_RELRO header from program headers) and calls_dl_protected_relro. Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu, aarch64-linux-gnu, s390x-linux-gnu, and sparc64-linux-gnu. I also check with --enable-static pie on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu which seems the only architectures where static PIE is actually working (as per 9d7a3741c9e, on arm-linux-gnueabihf, powerpc64{le}-linux-gnu, and s390x-linux-gnu I am seeing runtime issues not related to my patch). [1] https://sourceware.org/ml/libc-alpha/2019-10/msg00059.html --- elf/dl-support.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-)