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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2024-01-05 10:36:40 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2024-01-09 13:55:51 -0300
commit25f1e16ef03a6a8fb1701c4647d46c564480d88c (patch)
treec4f2b8148ab0fe004bae19105d8f8169ab9922a7 /sysdeps/x86_64
parentb7fc4a07f206a640e6d807d72f5c1ee3ea7a25b6 (diff)
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i386: Remove CET support
CET is only support for x86_64, this patch reverts:

  - faaee1f07ed x86: Support shadow stack pointer in setjmp/longjmp.
  - be9ccd27c09 i386: Add _CET_ENDBR to indirect jump targets in
    add_n.S/sub_n.S
  - c02695d7764 x86/CET: Update vfork to prevent child return
  - 5d844e1b725 i386: Enable CET support in ucontext functions
  - 124bcde683 x86: Add _CET_ENDBR to functions in crti.S
  - 562837c002 x86: Add _CET_ENDBR to functions in dl-tlsdesc.S
  - f753fa7dea x86: Support IBT and SHSTK in Intel CET [BZ #21598]
  - 825b58f3fb i386-mcount.S: Add _CET_ENDBR to _mcount and __fentry__
  - 7e119cd582 i386: Use _CET_NOTRACK in i686/memcmp.S
  - 177824e232 i386: Use _CET_NOTRACK in memcmp-sse4.S
  - 0a899af097 i386: Use _CET_NOTRACK in memcpy-ssse3-rep.S
  - 7fb613361c i386: Use _CET_NOTRACK in memcpy-ssse3.S
  - 77a8ae0948 i386: Use _CET_NOTRACK in memset-sse2-rep.S
  - 00e7b76a8f i386: Use _CET_NOTRACK in memset-sse2.S
  - 90d15dc577 i386: Use _CET_NOTRACK in strcat-sse2.S
  - f1574581c7 i386: Use _CET_NOTRACK in strcpy-sse2.S
  - 4031d7484a i386/sub_n.S: Add a missing _CET_ENDBR to indirect jump
  - target
  -
Checked on i686-linux-gnu.
Diffstat (limited to 'sysdeps/x86_64')
-rw-r--r--sysdeps/x86_64/sysdep.h42
1 files changed, 42 insertions, 0 deletions
diff --git a/sysdeps/x86_64/sysdep.h b/sysdeps/x86_64/sysdep.h
index 3e7f4cbd8a..db6e36b2dd 100644
--- a/sysdeps/x86_64/sysdep.h
+++ b/sysdeps/x86_64/sysdep.h
@@ -22,10 +22,52 @@
 #include <sysdeps/x86/sysdep.h>
 #include <x86-lp_size.h>
 
+/* __CET__ is defined by GCC with Control-Flow Protection values:
+
+enum cf_protection_level
+{
+  CF_NONE = 0,
+  CF_BRANCH = 1 << 0,
+  CF_RETURN = 1 << 1,
+  CF_FULL = CF_BRANCH | CF_RETURN,
+  CF_SET = 1 << 2
+};
+*/
+
+/* Set if CF_BRANCH (IBT) is enabled.  */
+#define X86_FEATURE_1_IBT	(1U << 0)
+/* Set if CF_RETURN (SHSTK) is enabled.  */
+#define X86_FEATURE_1_SHSTK	(1U << 1)
+
+#ifdef __CET__
+# define CET_ENABLED	1
+# define SHSTK_ENABLED	(__CET__ & X86_FEATURE_1_SHSTK)
+#else
+# define CET_ENABLED	0
+# define SHSTK_ENABLED	0
+#endif
+
 #ifdef	__ASSEMBLER__
 
 /* Syntactic details of assembler.  */
 
+#ifdef _CET_ENDBR
+# define _CET_NOTRACK notrack
+#else
+# define _CET_ENDBR
+# define _CET_NOTRACK
+#endif
+
+/* Define an entry point visible from C.  */
+#define	ENTRY_P2ALIGN(name, alignment)					      \
+  .globl C_SYMBOL_NAME(name);						      \
+  .type C_SYMBOL_NAME(name),@function;					      \
+  .align ALIGNARG(alignment);						      \
+  C_LABEL(name)								      \
+  cfi_startproc;							      \
+  _CET_ENDBR;								      \
+  CALL_MCOUNT
+
 /* This macro is for setting proper CFI with DW_CFA_expression describing
    the register as saved relative to %rsp instead of relative to the CFA.
    Expression is DW_OP_drop, DW_OP_breg7 (%rsp is register 7), sleb128 offset