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299 lines
9.8 KiB
299 lines
9.8 KiB
commit efb21b5fb27fbad447d9f242436fb591870f0045 |
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Author: Adhemerval Zanella <adhemerval.zanella@linaro.org> |
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Date: Mon Jan 24 10:46:16 2022 -0300 |
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elf: Fix initial-exec TLS access on audit modules (BZ #28096) |
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For audit modules and dependencies with initial-exec TLS, we can not |
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set the initial TLS image on default loader initialization because it |
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would already be set by the audit setup. However, subsequent thread |
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creation would need to follow the default behaviour. |
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This patch fixes it by setting l_auditing link_map field not only |
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for the audit modules, but also for all its dependencies. This is |
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used on _dl_allocate_tls_init to avoid the static TLS initialization |
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at load time. |
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Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. |
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Reviewed-by: Carlos O'Donell <carlos@redhat.com> |
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Tested-by: Carlos O'Donell <carlos@redhat.com> |
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(cherry picked from commit 254d3d5aef2fd8430c469e1938209ac100ebf132) |
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diff --git a/elf/Makefile b/elf/Makefile |
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index 407aaeaeb8c84020..3ccf78f62985e2d0 100644 |
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--- a/elf/Makefile |
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+++ b/elf/Makefile |
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@@ -367,6 +367,7 @@ tests += \ |
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tst-audit18 \ |
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tst-audit19b \ |
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tst-audit20 \ |
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+ tst-audit21 \ |
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tst-audit22 \ |
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tst-audit23 \ |
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tst-auditmany \ |
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@@ -654,6 +655,8 @@ modules-names = \ |
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tst-auditmod19a \ |
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tst-auditmod19b \ |
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tst-auditmod20 \ |
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+ tst-auditmod21a \ |
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+ tst-auditmod21b \ |
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tst-auditmod22 \ |
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tst-auditmod23 \ |
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tst-auxvalmod \ |
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@@ -2045,6 +2048,11 @@ tst-audit19b-ARGS = -- $(host-test-program-cmd) |
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$(objpfx)tst-audit20.out: $(objpfx)tst-auditmod20.so |
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tst-audit20-ENV = LD_AUDIT=$(objpfx)tst-auditmod20.so |
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+$(objpfx)tst-audit21: $(shared-thread-library) |
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+$(objpfx)tst-audit21.out: $(objpfx)tst-auditmod21a.so |
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+$(objpfx)tst-auditmod21a.so: $(objpfx)tst-auditmod21b.so |
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+tst-audit21-ENV = LD_AUDIT=$(objpfx)tst-auditmod21a.so |
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+ |
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$(objpfx)tst-audit22.out: $(objpfx)tst-auditmod22.so |
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tst-audit22-ARGS = -- $(host-test-program-cmd) |
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diff --git a/elf/dl-tls.c b/elf/dl-tls.c |
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index e2012d0cd515103b..fab6546e2d31edd4 100644 |
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--- a/elf/dl-tls.c |
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+++ b/elf/dl-tls.c |
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@@ -519,8 +519,12 @@ _dl_resize_dtv (dtv_t *dtv, size_t max_modid) |
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} |
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+/* Allocate initial TLS. RESULT should be a non-NULL pointer to storage |
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+ for the TLS space. The DTV may be resized, and so this function may |
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+ call malloc to allocate that space. The loader's GL(dl_load_tls_lock) |
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+ is taken when manipulating global TLS-related data in the loader. */ |
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void * |
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-_dl_allocate_tls_init (void *result) |
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+_dl_allocate_tls_init (void *result, bool init_tls) |
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{ |
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if (result == NULL) |
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/* The memory allocation failed. */ |
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@@ -593,7 +597,14 @@ _dl_allocate_tls_init (void *result) |
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some platforms use in static programs requires it. */ |
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dtv[map->l_tls_modid].pointer.val = dest; |
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- /* Copy the initialization image and clear the BSS part. */ |
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+ /* Copy the initialization image and clear the BSS part. For |
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+ audit modules or dependencies with initial-exec TLS, we can not |
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+ set the initial TLS image on default loader initialization |
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+ because it would already be set by the audit setup. However, |
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+ subsequent thread creation would need to follow the default |
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+ behaviour. */ |
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+ if (map->l_ns != LM_ID_BASE && !init_tls) |
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+ continue; |
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memset (__mempcpy (dest, map->l_tls_initimage, |
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map->l_tls_initimage_size), '\0', |
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map->l_tls_blocksize - map->l_tls_initimage_size); |
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@@ -620,7 +631,7 @@ _dl_allocate_tls (void *mem) |
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{ |
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return _dl_allocate_tls_init (mem == NULL |
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? _dl_allocate_tls_storage () |
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- : allocate_dtv (mem)); |
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+ : allocate_dtv (mem), true); |
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} |
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rtld_hidden_def (_dl_allocate_tls) |
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diff --git a/elf/rtld.c b/elf/rtld.c |
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index b089e5cf4740443e..26c6fb6479c9008c 100644 |
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--- a/elf/rtld.c |
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+++ b/elf/rtld.c |
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@@ -2429,7 +2429,7 @@ dl_main (const ElfW(Phdr) *phdr, |
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into the main thread's TLS area, which we allocated above. |
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Note: thread-local variables must only be accessed after completing |
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the next step. */ |
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- _dl_allocate_tls_init (tcbp); |
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+ _dl_allocate_tls_init (tcbp, false); |
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/* And finally install it for the main thread. */ |
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if (! tls_init_tp_called) |
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diff --git a/elf/tst-audit21.c b/elf/tst-audit21.c |
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new file mode 100644 |
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index 0000000000000000..3a47ab64d44421ee |
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--- /dev/null |
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+++ b/elf/tst-audit21.c |
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@@ -0,0 +1,42 @@ |
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+/* Check LD_AUDIT with static TLS. |
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+ Copyright (C) 2022 Free Software Foundation, Inc. |
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+ This file is part of the GNU C Library. |
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+ |
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+ The GNU C Library is free software; you can redistribute it and/or |
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+ modify it under the terms of the GNU Lesser General Public |
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+ License as published by the Free Software Foundation; either |
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+ version 2.1 of the License, or (at your option) any later version. |
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+ |
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+ The GNU C Library is distributed in the hope that it will be useful, |
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+ but WITHOUT ANY WARRANTY; without even the implied warranty of |
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+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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+ Lesser General Public License for more details. |
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+ |
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+ You should have received a copy of the GNU Lesser General Public |
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+ License along with the GNU C Library; if not, see |
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+ <https://www.gnu.org/licenses/>. */ |
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+ |
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+#include <ctype.h> |
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+#include <support/xthread.h> |
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+#include <support/check.h> |
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+ |
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+static volatile __thread int out __attribute__ ((tls_model ("initial-exec"))); |
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+ |
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+static void * |
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+tf (void *arg) |
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+{ |
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+ TEST_COMPARE (out, 0); |
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+ out = isspace (' '); |
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+ return NULL; |
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+} |
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+ |
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+int main (int argc, char *argv[]) |
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+{ |
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+ TEST_COMPARE (out, 0); |
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+ out = isspace (' '); |
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+ |
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+ pthread_t t = xpthread_create (NULL, tf, NULL); |
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+ xpthread_join (t); |
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+ |
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+ return 0; |
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+} |
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diff --git a/elf/tst-auditmod21a.c b/elf/tst-auditmod21a.c |
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new file mode 100644 |
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index 0000000000000000..f6d51b5c0531c49d |
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--- /dev/null |
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+++ b/elf/tst-auditmod21a.c |
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@@ -0,0 +1,80 @@ |
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+/* Check LD_AUDIT with static TLS. |
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+ Copyright (C) 2022 Free Software Foundation, Inc. |
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+ This file is part of the GNU C Library. |
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+ |
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+ The GNU C Library is free software; you can redistribute it and/or |
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+ modify it under the terms of the GNU Lesser General Public |
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+ License as published by the Free Software Foundation; either |
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+ version 2.1 of the License, or (at your option) any later version. |
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+ |
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+ The GNU C Library is distributed in the hope that it will be useful, |
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+ but WITHOUT ANY WARRANTY; without even the implied warranty of |
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+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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+ Lesser General Public License for more details. |
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+ |
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+ You should have received a copy of the GNU Lesser General Public |
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+ License along with the GNU C Library; if not, see |
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+ <https://www.gnu.org/licenses/>. */ |
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+ |
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+#include <ctype.h> |
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+#include <stdlib.h> |
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+#include <link.h> |
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+ |
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+#define tls_ie __attribute__ ((tls_model ("initial-exec"))) |
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+ |
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+__thread int tls_var0 tls_ie; |
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+__thread int tls_var1 tls_ie = 0x10; |
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+ |
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+/* Defined at tst-auditmod21b.so */ |
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+extern __thread int tls_var2; |
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+extern __thread int tls_var3; |
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+ |
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+static volatile int out; |
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+ |
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+static void |
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+call_libc (void) |
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+{ |
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+ /* isspace accesses the initial-exec glibc TLS variables, which are |
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+ setup in glibc initialization. */ |
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+ out = isspace (' '); |
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+} |
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+ |
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+unsigned int |
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+la_version (unsigned int v) |
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+{ |
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+ tls_var0 = 0x1; |
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+ if (tls_var1 != 0x10) |
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+ abort (); |
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+ tls_var1 = 0x20; |
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+ |
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+ tls_var2 = 0x2; |
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+ if (tls_var3 != 0x20) |
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+ abort (); |
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+ tls_var3 = 0x40; |
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+ |
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+ call_libc (); |
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+ |
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+ return LAV_CURRENT; |
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+} |
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+ |
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+unsigned int |
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+la_objopen (struct link_map* map, Lmid_t lmid, uintptr_t* cookie) |
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+{ |
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+ call_libc (); |
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+ *cookie = (uintptr_t) map; |
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+ return 0; |
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+} |
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+ |
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+void |
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+la_activity (uintptr_t* cookie, unsigned int flag) |
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+{ |
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+ if (tls_var0 != 0x1 || tls_var1 != 0x20) |
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+ abort (); |
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+ call_libc (); |
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+} |
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+ |
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+void |
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+la_preinit (uintptr_t* cookie) |
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+{ |
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+ call_libc (); |
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+} |
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diff --git a/elf/tst-auditmod21b.c b/elf/tst-auditmod21b.c |
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new file mode 100644 |
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index 0000000000000000..6ba5335b7514c674 |
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--- /dev/null |
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+++ b/elf/tst-auditmod21b.c |
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@@ -0,0 +1,22 @@ |
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+/* Check LD_AUDIT with static TLS. |
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+ Copyright (C) 2022 Free Software Foundation, Inc. |
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+ This file is part of the GNU C Library. |
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+ |
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+ The GNU C Library is free software; you can redistribute it and/or |
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+ modify it under the terms of the GNU Lesser General Public |
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+ License as published by the Free Software Foundation; either |
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+ version 2.1 of the License, or (at your option) any later version. |
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+ |
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+ The GNU C Library is distributed in the hope that it will be useful, |
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+ but WITHOUT ANY WARRANTY; without even the implied warranty of |
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+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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+ Lesser General Public License for more details. |
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+ |
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+ You should have received a copy of the GNU Lesser General Public |
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+ License along with the GNU C Library; if not, see |
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+ <https://www.gnu.org/licenses/>. */ |
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+ |
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+#define tls_ie __attribute__ ((tls_model ("initial-exec"))) |
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+ |
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+__thread int tls_var2 tls_ie; |
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+__thread int tls_var3 tls_ie = 0x20; |
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diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c |
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index 50065bc9bd8a28e5..554a721f814b53c4 100644 |
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--- a/nptl/allocatestack.c |
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+++ b/nptl/allocatestack.c |
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@@ -139,7 +139,7 @@ get_cached_stack (size_t *sizep, void **memp) |
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memset (dtv, '\0', (dtv[-1].counter + 1) * sizeof (dtv_t)); |
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/* Re-initialize the TLS. */ |
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- _dl_allocate_tls_init (TLS_TPADJ (result)); |
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+ _dl_allocate_tls_init (TLS_TPADJ (result), true); |
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return result; |
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} |
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diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h |
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index 686f0a7b9709eb10..a56060d0204cc453 100644 |
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--- a/sysdeps/generic/ldsodefs.h |
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+++ b/sysdeps/generic/ldsodefs.h |
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@@ -1254,7 +1254,7 @@ extern void _dl_allocate_static_tls (struct link_map *map) attribute_hidden; |
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/* These are internal entry points to the two halves of _dl_allocate_tls, |
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only used within rtld.c itself at startup time. */ |
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extern void *_dl_allocate_tls_storage (void) attribute_hidden; |
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-extern void *_dl_allocate_tls_init (void *); |
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+extern void *_dl_allocate_tls_init (void *, bool); |
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rtld_hidden_proto (_dl_allocate_tls_init) |
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/* Deallocate memory allocated with _dl_allocate_tls. */
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