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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2021-06-25 10:54:12 -0300 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2021-07-14 15:10:27 -0300 |
| commit | ba33937be210da5d07f7f01709323743f66011ce (patch) | |
| tree | 8de2c3d81913a4e6b40b1f903078ce190d2f17be /elf/dl-close.c | |
| parent | 0e1f068108d94576321bbbd354cfb1b3b99389bf (diff) | |
| download | glibc-ba33937be210da5d07f7f01709323743f66011ce.zip glibc-ba33937be210da5d07f7f01709323743f66011ce.tar.gz glibc-ba33937be210da5d07f7f01709323743f66011ce.tar.bz2 | |
elf: Fix DTV gap reuse logic (BZ #27135)
This is updated version of the 572bd547d57a (reverted by 40ebfd016ad2)
that fixes the _dl_next_tls_modid issues.
This issue with 572bd547d57a patch is the DTV entry will be only
update on dl_open_worker() with the update_tls_slotinfo() call after
all dependencies are being processed by _dl_map_object_deps(). However
_dl_map_object_deps() itself might call _dl_next_tls_modid(), and since
the _dl_tls_dtv_slotinfo_list::map is not yet set the entry will be
wrongly reused.
This patch fixes by renaming the _dl_next_tls_modid() function to
_dl_assign_tls_modid() and by passing the link_map so it can set
the slotinfo value so a subsequente _dl_next_tls_modid() call will
see the entry as allocated.
The intermediary value is cleared up on remove_slotinfo() for the case
a library fails to load with RTLD_NOW.
This patch fixes BZ #27135.
Checked on x86_64-linux-gnu.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Diffstat (limited to 'elf/dl-close.c')
| -rw-r--r-- | elf/dl-close.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/elf/dl-close.c b/elf/dl-close.c index 3720e47..f39001c 100644 --- a/elf/dl-close.c +++ b/elf/dl-close.c @@ -77,8 +77,6 @@ remove_slotinfo (size_t idx, struct dtv_slotinfo_list *listp, size_t disp, object that wasn't fully set up. */ if (__glibc_likely (old_map != NULL)) { - assert (old_map->l_tls_modid == idx); - /* Mark the entry as unused. These can be read concurrently. */ atomic_store_relaxed (&listp->slotinfo[idx - disp].gen, GL(dl_tls_generation) + 1); @@ -88,7 +86,11 @@ remove_slotinfo (size_t idx, struct dtv_slotinfo_list *listp, size_t disp, /* If this is not the last currently used entry no need to look further. */ if (idx != GL(dl_tls_max_dtv_idx)) - return true; + { + /* There is an unused dtv entry in the middle. */ + GL(dl_tls_dtv_gaps) = true; + return true; + } } while (idx - disp > (disp == 0 ? 1 + GL(dl_tls_static_nelem) : 0)) |