| Message ID | d15e429fa392913292880f71fcbccf4826cd52d8.1606908528.git.fweimer@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2,1/2] Replace __libc_multiple_libcs with __libc_initial flag | expand |
On 02/12/2020 08:30, Florian Weimer via Libc-alpha wrote: > The secondary/non-primary/inner libc (loaded via dlmopen, LD_AUDIT, > static dlopen) must not use sbrk to allocate member because that would > interfere with allocations in the outer libc. On Linux, this does not > matter because sbrk itself was changed to fail in secondary libcs. > > _dl_addr occasionally shows up in profiles, but had to be used before > because __libc_multiple_libs was unreliable. So this change achieves > a slight reduction in startup time. LGTM, thanks. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> > --- > v2: Adjust to the first patch. > > malloc/arena.c | 13 +++++-------- > malloc/malloc.c | 2 ++ > 2 files changed, 7 insertions(+), 8 deletions(-) > > diff --git a/malloc/arena.c b/malloc/arena.c > index 202daf15b0..3c9c0ecd86 100644 > --- a/malloc/arena.c > +++ b/malloc/arena.c > @@ -294,14 +294,11 @@ ptmalloc_init (void) > __malloc_initialized = 0; > > #ifdef SHARED > - /* In case this libc copy is in a non-default namespace, never use brk. > - Likewise if dlopened from statically linked program. */ > - Dl_info di; > - struct link_map *l; > - > - if (_dl_open_hook != NULL > - || (_dl_addr (ptmalloc_init, &di, &l, NULL) != 0 > - && l->l_ns != LM_ID_BASE)) > + /* In case this libc copy is in a non-default namespace, never use > + brk. Likewise if dlopened from statically linked program. The > + generic sbrk implementation also enforces this, but it is not > + used on Hurd. */ > + if (!__libc_initial) > __morecore = __failing_morecore; > #endif > Ok. > diff --git a/malloc/malloc.c b/malloc/malloc.c > index 5b87bdb081..0834e4181a 100644 > --- a/malloc/malloc.c > +++ b/malloc/malloc.c > @@ -247,6 +247,8 @@ > /* For SINGLE_THREAD_P. */ > #include <sysdep-cancel.h> > > +#include <libc-internal.h> > + > /* > Debugging: > > Ok.
diff --git a/malloc/arena.c b/malloc/arena.c index 202daf15b0..3c9c0ecd86 100644 --- a/malloc/arena.c +++ b/malloc/arena.c @@ -294,14 +294,11 @@ ptmalloc_init (void) __malloc_initialized = 0; #ifdef SHARED - /* In case this libc copy is in a non-default namespace, never use brk. - Likewise if dlopened from statically linked program. */ - Dl_info di; - struct link_map *l; - - if (_dl_open_hook != NULL - || (_dl_addr (ptmalloc_init, &di, &l, NULL) != 0 - && l->l_ns != LM_ID_BASE)) + /* In case this libc copy is in a non-default namespace, never use + brk. Likewise if dlopened from statically linked program. The + generic sbrk implementation also enforces this, but it is not + used on Hurd. */ + if (!__libc_initial) __morecore = __failing_morecore; #endif diff --git a/malloc/malloc.c b/malloc/malloc.c index 5b87bdb081..0834e4181a 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -247,6 +247,8 @@ /* For SINGLE_THREAD_P. */ #include <sysdep-cancel.h> +#include <libc-internal.h> + /* Debugging: