diff options
Diffstat (limited to 'meta/recipes-core/glibc/glibc/0034-elf-Fix-DTV-gap-reuse-logic-BZ-27135.patch')
| -rw-r--r-- | meta/recipes-core/glibc/glibc/0034-elf-Fix-DTV-gap-reuse-logic-BZ-27135.patch | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/meta/recipes-core/glibc/glibc/0034-elf-Fix-DTV-gap-reuse-logic-BZ-27135.patch b/meta/recipes-core/glibc/glibc/0034-elf-Fix-DTV-gap-reuse-logic-BZ-27135.patch new file mode 100644 index 0000000000..a87afe3230 --- /dev/null +++ b/meta/recipes-core/glibc/glibc/0034-elf-Fix-DTV-gap-reuse-logic-BZ-27135.patch @@ -0,0 +1,180 @@ +From ba33937be210da5d07f7f01709323743f66011ce Mon Sep 17 00:00:00 2001 +From: Adhemerval Zanella <adhemerval.zanella@linaro.org> +Date: Fri, 25 Jun 2021 10:54:12 -0300 +Subject: [PATCH] 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> +--- + elf/dl-close.c | 8 +- + elf/dl-load.c | 2 +- + elf/dl-open.c | 10 -- + elf/dl-tls.c | 17 +-- + elf/rtld.c | 2 +- + sysdeps/generic/ldsodefs.h | 4 +- + 6 files changed, 349 insertions(+), 33 deletions(-) +--- +Upstream-Status: Backport [https://sourceware.org/git/?p=glibc.git;a=patch;h=ba33937be210da5d07f7f01709323743f66011ce] +Comment: Removed hunks those were related to test. Hunk from elf/rtld.c is refreshed. +Signed-off-by: Akash Hadke <akash.hadke@kpit.com> +Signed-off-by: Akash Hadke <hadkeakash4@gmail.com> +--- +diff --git a/elf/dl-close.c b/elf/dl-close.c +index 3720e47dd1..f39001cab9 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)) +diff --git a/elf/dl-load.c b/elf/dl-load.c +index a08df001af..650e4edc35 100644 +--- a/elf/dl-load.c ++++ b/elf/dl-load.c +@@ -1498,7 +1498,7 @@ cannot enable executable stack as shared object requires"); + not set up TLS data structures, so don't use them now. */ + || __glibc_likely (GL(dl_tls_dtv_slotinfo_list) != NULL))) + /* Assign the next available module ID. */ +- l->l_tls_modid = _dl_next_tls_modid (); ++ _dl_assign_tls_modid (l); + + #ifdef DL_AFTER_LOAD + DL_AFTER_LOAD (l); +diff --git a/elf/dl-open.c b/elf/dl-open.c +index a066f39bd0..d2240d8747 100644 +--- a/elf/dl-open.c ++++ b/elf/dl-open.c +@@ -899,16 +899,6 @@ no more namespaces available for dlmopen()")); + state if relocation failed, for example. */ + if (args.map) + { +- /* Maybe some of the modules which were loaded use TLS. +- Since it will be removed in the following _dl_close call +- we have to mark the dtv array as having gaps to fill the +- holes. This is a pessimistic assumption which won't hurt +- if not true. There is no need to do this when we are +- loading the auditing DSOs since TLS has not yet been set +- up. */ +- if ((mode & __RTLD_AUDIT) == 0) +- GL(dl_tls_dtv_gaps) = true; +- + _dl_close_worker (args.map, true); + + /* All l_nodelete_pending objects should have been deleted +diff --git a/elf/dl-tls.c b/elf/dl-tls.c +index 2b5161d10a..423e380f7c 100644 +--- a/elf/dl-tls.c ++++ b/elf/dl-tls.c +@@ -126,8 +126,8 @@ oom (void) + } + + +-size_t +-_dl_next_tls_modid (void) ++void ++_dl_assign_tls_modid (struct link_map *l) + { + size_t result; + +@@ -157,7 +157,11 @@ _dl_next_tls_modid (void) + } + + if (result - disp < runp->len) +- break; ++ { ++ /* Mark the entry as used, so any dependency see it. */ ++ atomic_store_relaxed (&runp->slotinfo[result - disp].map, l); ++ break; ++ } + + disp += runp->len; + } +@@ -184,17 +188,14 @@ _dl_next_tls_modid (void) + atomic_store_relaxed (&GL(dl_tls_max_dtv_idx), result); + } + +- return result; ++ l->l_tls_modid = result; + } + + + size_t + _dl_count_modids (void) + { +- /* It is rare that we have gaps; see elf/dl-open.c (_dl_open) where +- we fail to load a module and unload it leaving a gap. If we don't +- have gaps then the number of modids is the current maximum so +- return that. */ ++ /* The count is the max unless dlclose or failed dlopen created gaps. */ + if (__glibc_likely (!GL(dl_tls_dtv_gaps))) + return GL(dl_tls_max_dtv_idx); + +diff --git a/elf/rtld.c b/elf/rtld.c +index e3fb2a5b2a..d733359eaf 100644 +--- a/elf/rtld.c ++++ b/elf/rtld.c +@@ -1612,7 +1612,7 @@ + /* Add the dynamic linker to the TLS list if it also uses TLS. */ + if (GL(dl_rtld_map).l_tls_blocksize != 0) + /* Assign a module ID. Do this before loading any audit modules. */ +- GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid (); ++ _dl_assign_tls_modid (&GL(dl_rtld_map)); + + /* If we have auditing DSOs to load, do it now. */ + bool need_security_init = true; +diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h +index 176394de4d..9c15259236 100644 +--- a/sysdeps/generic/ldsodefs.h ++++ b/sysdeps/generic/ldsodefs.h +@@ -1171,8 +1171,8 @@ extern ElfW(Addr) _dl_sysdep_start (void **start_argptr, + extern void _dl_sysdep_start_cleanup (void) attribute_hidden; + + +-/* Determine next available module ID. */ +-extern size_t _dl_next_tls_modid (void) attribute_hidden; ++/* Determine next available module ID and set the L l_tls_modid. */ ++extern void _dl_assign_tls_modid (struct link_map *l) attribute_hidden; + + /* Count the modules with TLS segments. */ + extern size_t _dl_count_modids (void) attribute_hidden; +-- +2.27.0 |