| Message ID | 36d457074f389740b45afc4f9c6d124046f8352b.1606319495.git.szabolcs.nagy@arm.com |
|---|---|
| State | New |
| Headers | show |
| Series | aarch64: avoid mprotect(PROT_BTI|PROT_EXEC) [BZ #26831] | expand |
On 27/11/2020 10:20, Szabolcs Nagy via Libc-alpha wrote: > Program headers are processed in two pass: after the first pass > load segments are mmapped so in the second pass target specific > note processing logic can access the notes. > > The second pass is moved later so various link_map fields are > set up that may be useful for note processing such as l_phdr. > The second pass should be before the fd is closed so that is > available. LGTM, thanks. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> > --- > elf/dl-load.c | 30 +++++++++++++++--------------- > 1 file changed, 15 insertions(+), 15 deletions(-) > > diff --git a/elf/dl-load.c b/elf/dl-load.c > index 9c71b7562c..b0d65f32cc 100644 > --- a/elf/dl-load.c > +++ b/elf/dl-load.c > @@ -1268,21 +1268,6 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, > l->l_map_start = l->l_map_end = 0; > goto call_lose; > } > - > - /* Process program headers again after load segments are mapped in > - case processing requires accessing those segments. Scan program > - headers backward so that PT_NOTE can be skipped if PT_GNU_PROPERTY > - exits. */ > - for (ph = &phdr[l->l_phnum]; ph != phdr; --ph) > - switch (ph[-1].p_type) > - { > - case PT_NOTE: > - _dl_process_pt_note (l, &ph[-1]); > - break; > - case PT_GNU_PROPERTY: > - _dl_process_pt_gnu_property (l, &ph[-1]); > - break; > - } > } > > if (l->l_ld == 0) > @@ -1386,6 +1371,21 @@ cannot enable executable stack as shared object requires"); > if (l->l_tls_initimage != NULL) > l->l_tls_initimage = (char *) l->l_tls_initimage + l->l_addr; > > + /* Process program headers again after load segments are mapped in > + case processing requires accessing those segments. Scan program > + headers backward so that PT_NOTE can be skipped if PT_GNU_PROPERTY > + exits. */ > + for (ph = &l->l_phdr[l->l_phnum]; ph != l->l_phdr; --ph) > + switch (ph[-1].p_type) > + { > + case PT_NOTE: > + _dl_process_pt_note (l, &ph[-1]); > + break; > + case PT_GNU_PROPERTY: > + _dl_process_pt_gnu_property (l, &ph[-1]); > + break; > + } > + > /* We are done mapping in the file. We no longer need the descriptor. */ > if (__glibc_unlikely (__close_nocancel (fd) != 0)) > { >
diff --git a/elf/dl-load.c b/elf/dl-load.c index 9c71b7562c..b0d65f32cc 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -1268,21 +1268,6 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, l->l_map_start = l->l_map_end = 0; goto call_lose; } - - /* Process program headers again after load segments are mapped in - case processing requires accessing those segments. Scan program - headers backward so that PT_NOTE can be skipped if PT_GNU_PROPERTY - exits. */ - for (ph = &phdr[l->l_phnum]; ph != phdr; --ph) - switch (ph[-1].p_type) - { - case PT_NOTE: - _dl_process_pt_note (l, &ph[-1]); - break; - case PT_GNU_PROPERTY: - _dl_process_pt_gnu_property (l, &ph[-1]); - break; - } } if (l->l_ld == 0) @@ -1386,6 +1371,21 @@ cannot enable executable stack as shared object requires"); if (l->l_tls_initimage != NULL) l->l_tls_initimage = (char *) l->l_tls_initimage + l->l_addr; + /* Process program headers again after load segments are mapped in + case processing requires accessing those segments. Scan program + headers backward so that PT_NOTE can be skipped if PT_GNU_PROPERTY + exits. */ + for (ph = &l->l_phdr[l->l_phnum]; ph != l->l_phdr; --ph) + switch (ph[-1].p_type) + { + case PT_NOTE: + _dl_process_pt_note (l, &ph[-1]); + break; + case PT_GNU_PROPERTY: + _dl_process_pt_gnu_property (l, &ph[-1]); + break; + } + /* We are done mapping in the file. We no longer need the descriptor. */ if (__glibc_unlikely (__close_nocancel (fd) != 0)) {