elf: Clarify and invert second argument of _dl_allocate_tls_init

Also remove an outdated comment: _dl_allocate_tls_init is
called as part of pthread_create.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This commit is contained in:
Florian Weimer 2024-08-01 23:31:23 +02:00
parent 39ca997ab3
commit fe06fb313b
4 changed files with 12 additions and 9 deletions

View File

@ -552,9 +552,14 @@ _dl_resize_dtv (dtv_t *dtv, size_t max_modid)
/* Allocate initial TLS. RESULT should be a non-NULL pointer to storage
for the TLS space. The DTV may be resized, and so this function may
call malloc to allocate that space. The loader's GL(dl_load_tls_lock)
is taken when manipulating global TLS-related data in the loader. */
is taken when manipulating global TLS-related data in the loader.
If MAIN_THREAD, this is the first call during process
initialization. In this case, TLS initialization for secondary
(audit) namespaces is skipped because that has already been handled
by dlopen. */
void *
_dl_allocate_tls_init (void *result, bool init_tls)
_dl_allocate_tls_init (void *result, bool main_thread)
{
if (result == NULL)
/* The memory allocation failed. */
@ -633,7 +638,7 @@ _dl_allocate_tls_init (void *result, bool init_tls)
because it would already be set by the audit setup. However,
subsequent thread creation would need to follow the default
behaviour. */
if (map->l_ns != LM_ID_BASE && !init_tls)
if (map->l_ns != LM_ID_BASE && main_thread)
continue;
memset (__mempcpy (dest, map->l_tls_initimage,
map->l_tls_initimage_size), '\0',
@ -661,7 +666,7 @@ _dl_allocate_tls (void *mem)
{
return _dl_allocate_tls_init (mem == NULL
? _dl_allocate_tls_storage ()
: allocate_dtv (mem), true);
: allocate_dtv (mem), false);
}
rtld_hidden_def (_dl_allocate_tls)

View File

@ -2338,7 +2338,7 @@ dl_main (const ElfW(Phdr) *phdr,
into the main thread's TLS area, which we allocated above.
Note: thread-local variables must only be accessed after completing
the next step. */
_dl_allocate_tls_init (tcbp, false);
_dl_allocate_tls_init (tcbp, true);
/* And finally install it for the main thread. */
if (! __rtld_tls_init_tp_called)

View File

@ -139,7 +139,7 @@ get_cached_stack (size_t *sizep, void **memp)
memset (dtv, '\0', (dtv[-1].counter + 1) * sizeof (dtv_t));
/* Re-initialize the TLS. */
_dl_allocate_tls_init (TLS_TPADJ (result), true);
_dl_allocate_tls_init (TLS_TPADJ (result), false);
return result;
}

View File

@ -1200,10 +1200,8 @@ extern void _dl_get_tls_static_info (size_t *sizep, size_t *alignp);
extern void _dl_allocate_static_tls (struct link_map *map) attribute_hidden;
/* These are internal entry points to the two halves of _dl_allocate_tls,
only used within rtld.c itself at startup time. */
extern void *_dl_allocate_tls_storage (void) attribute_hidden;
extern void *_dl_allocate_tls_init (void *, bool);
extern void *_dl_allocate_tls_init (void *result, bool main_thread);
rtld_hidden_proto (_dl_allocate_tls_init)
/* True if the TCB has been set up. */