x86: Set header.feature_1 in TCB for always-on CET [BZ #27177]

Update dl_cet_check() to set header.feature_1 in TCB when both IBT and
SHSTK are always on.

(cherry picked from commit 2ef23b520597f4ea1790a669b83e608f24f4cf12)

diff --git a/NEWS b/NEWS
index 271f0333147380eedcec07180b2c590e7a93744d..4f9e4138b8a5a086a96f518697689304e5563cb7 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -77,6 +77,7 @@ The following bugs are resolved with this release:
   [25423] Array overflow in backtrace on powerpc
   [25933] Off by one error in __strncmp_avx2
   [27130] "rep movsb" performance issue
+  [27177] GLIBC_TUNABLES=glibc.cpu.x86_ibt=on:glibc.cpu.x86_shstk=on doesn't work
 
 Security related changes:
 

diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
index 43ad4a79ff60273a4d5e20af9a2402f8c9fb74b0..891a4fdbb042efccf11fda854fb04845eca8bd20 100644 (file)
--- a/sysdeps/x86/Makefile
+++ b/sysdeps/x86/Makefile
@@ -12,6 +12,12 @@ endif
 ifeq ($(subdir),setjmp)
 gen-as-const-headers += jmp_buf-ssp.sym
 sysdep_routines += __longjmp_cancel
+ifneq ($(enable-cet),no)
+ifneq ($(have-tunables),no)
+tests += tst-setjmp-cet
+tst-setjmp-cet-ENV = GLIBC_TUNABLES=glibc.cpu.x86_ibt=on:glibc.cpu.x86_shstk=on
+endif
+endif
 endif
 
 ifeq ($(enable-cet),yes)

diff --git a/sysdeps/x86/dl-cet.c b/sysdeps/x86/dl-cet.c
index b82ba14e75b56c585bc8e86e3b2cbb52c78bb503..56c37bcd4f468b77f7e220d14a0d3ee6d158ac06 100644 (file)
--- a/sysdeps/x86/dl-cet.c
+++ b/sysdeps/x86/dl-cet.c
@@ -105,7 +105,11 @@ dl_cet_check (struct link_map *m, const char *program)
   /* No legacy object check if both IBT and SHSTK are always on.  */
   if (enable_ibt_type == CET_ALWAYS_ON
       && enable_shstk_type == CET_ALWAYS_ON)
-    return;
+    {
+      THREAD_SETMEM (THREAD_SELF, header.feature_1,
+                    GL(dl_x86_feature_1)[0]);
+      return;
+    }
 
   /* Check if IBT is enabled by kernel.  */
   bool ibt_enabled

diff --git a/sysdeps/x86/tst-setjmp-cet.c b/sysdeps/x86/tst-setjmp-cet.c
new file mode 100644 (file)
index 0000000..42c795d
--- /dev/null
+++ b/sysdeps/x86/tst-setjmp-cet.c
@@ -0,0 +1 @@
+#include <setjmp/tst-setjmp.c>