| Message ID | 87a5qlgire.fsf@oldenburg.str.redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | elf: Initialize GLRO(dl_lazy) before relocating libc in dynamic startup | expand |
On 12/8/23 04:12, Florian Weimer wrote: > GLRO(dl_lazy) is used to set the parameters for the early > _dl_relocate_object call, so the consider_profiling setting has to > be applied before the call. Yes, GLRO(dl_lazy) must be set early enough for this to work for relocation, and it should turn on if profiling is enabled. In the old code this wasn't a problem because we only did the relocation later in a loop, but with early init we need to set this earlier too. > > Fixes commit 78ca44da0160a0b442f0ca1f253e3360f044b2ec ("elf: Relocate > libc.so early during startup and dlmopen (bug 31083)"). Reviewed-by: Carlos O'Donell <carlos@redhat.com> > --- > elf/rtld.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/elf/rtld.c b/elf/rtld.c > index f0b0f3328d..326286f3b2 100644 > --- a/elf/rtld.c > +++ b/elf/rtld.c > @@ -2278,14 +2278,14 @@ dl_main (const ElfW(Phdr) *phdr, > > int consider_profiling = GLRO(dl_profile) != NULL; > > + /* If we are profiling we also must do lazy reloaction. */ > + GLRO(dl_lazy) |= consider_profiling; OK. Agreed, this needs to move ahead of the *first* call to _dl_relocate_object(). > + > if (GL(dl_ns)[LM_ID_BASE].libc_map != NULL) > _dl_relocate_object (GL(dl_ns)[LM_ID_BASE].libc_map, > GL(dl_ns)[LM_ID_BASE].libc_map->l_scope, > GLRO(dl_lazy) ? RTLD_LAZY : 0, consider_profiling); > > - /* If we are profiling we also must do lazy reloaction. */ > - GLRO(dl_lazy) |= consider_profiling; > - OK. > RTLD_TIMING_VAR (start); > rtld_timer_start (&start); > { > > base-commit: 958478889c6a7a12b35b857b9788b7ad8706a01e >
diff --git a/elf/rtld.c b/elf/rtld.c index f0b0f3328d..326286f3b2 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -2278,14 +2278,14 @@ dl_main (const ElfW(Phdr) *phdr, int consider_profiling = GLRO(dl_profile) != NULL; + /* If we are profiling we also must do lazy reloaction. */ + GLRO(dl_lazy) |= consider_profiling; + if (GL(dl_ns)[LM_ID_BASE].libc_map != NULL) _dl_relocate_object (GL(dl_ns)[LM_ID_BASE].libc_map, GL(dl_ns)[LM_ID_BASE].libc_map->l_scope, GLRO(dl_lazy) ? RTLD_LAZY : 0, consider_profiling); - /* If we are profiling we also must do lazy reloaction. */ - GLRO(dl_lazy) |= consider_profiling; - RTLD_TIMING_VAR (start); rtld_timer_start (&start); {
GLRO(dl_lazy) is used to set the parameters for the early _dl_relocate_object call, so the consider_profiling setting has to be applied before the call. Fixes commit 78ca44da0160a0b442f0ca1f253e3360f044b2ec ("elf: Relocate libc.so early during startup and dlmopen (bug 31083)"). --- elf/rtld.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) base-commit: 958478889c6a7a12b35b857b9788b7ad8706a01e