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i386: Remove CET support

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CET is only support for x86_64, this patch reverts:

  - faaee1f07e x86: Support shadow stack pointer in setjmp/longjmp.
  - be9ccd27c0 i386: Add _CET_ENDBR to indirect jump targets in
    add_n.S/sub_n.S
  - c02695d776 x86/CET: Update vfork to prevent child return
  - 5d844e1b72 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.
This commit is contained in:
Adhemerval Zanella 2024-01-05 10:36:40 -03:00
parent b7fc4a07f2
commit 25f1e16ef0
31 changed files with 75 additions and 770 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

73
sysdeps/i386/__longjmp.S
View File

@ -19,55 +19,14 @@
#include <sysdep.h> #include <sysdep.h>
#include <pointer_guard.h> #include <pointer_guard.h>
#include <jmpbuf-offsets.h> #include <jmpbuf-offsets.h>
#include <jmp_buf-ssp.h>
#include <asm-syntax.h> #include <asm-syntax.h>
#include <stap-probe.h> #include <stap-probe.h>
/* Don't restore shadow stack register if
1. Shadow stack isn't enabled. Or
2. __longjmp is defined for __longjmp_cancel.
*/
#if !SHSTK_ENABLED || defined __longjmp
# undef SHADOW_STACK_POINTER_OFFSET
#endif
.text .text
ENTRY (__longjmp) ENTRY (__longjmp)
#ifdef PTR_DEMANGLE #ifdef PTR_DEMANGLE
movl 4(%esp), %eax /* User's jmp_buf in %eax. */ movl 4(%esp), %eax /* User's jmp_buf in %eax. */
# ifdef SHADOW_STACK_POINTER_OFFSET
# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
/* Check if Shadow Stack is enabled. */
testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
jz L(skip_ssp)
# else
xorl %edx, %edx
# endif
/* Check and adjust the Shadow-Stack-Pointer. */
rdsspd %edx
/* And compare it with the saved ssp value. */
subl SHADOW_STACK_POINTER_OFFSET(%eax), %edx
je L(skip_ssp)
/* Count the number of frames to adjust and adjust it
with incssp instruction. The instruction can adjust
the ssp by [0..255] value only thus use a loop if
the number of frames is bigger than 255. */
negl %edx
shrl $2, %edx
/* NB: We saved Shadow-Stack-Pointer of setjmp. Since we are
restoring Shadow-Stack-Pointer of setjmp's caller, we
need to unwind shadow stack by one more frame. */
addl $1, %edx
movl $255, %ebx
L(loop):
cmpl %ebx, %edx
cmovb %edx, %ebx
incsspd %ebx
subl %ebx, %edx
ja L(loop)
L(skip_ssp):
# endif
/* Save the return address now. */ /* Save the return address now. */
movl (JB_PC*4)(%eax), %edx movl (JB_PC*4)(%eax), %edx
/* Get the stack pointer. */ /* Get the stack pointer. */
@ -98,38 +57,6 @@ L(skip_ssp):
#else #else
movl 4(%esp), %ecx /* User's jmp_buf in %ecx. */ movl 4(%esp), %ecx /* User's jmp_buf in %ecx. */
movl 8(%esp), %eax /* Second argument is return value. */ movl 8(%esp), %eax /* Second argument is return value. */
# ifdef SHADOW_STACK_POINTER_OFFSET
# if IS_IN (libc) && defined SHARED
/* Check if Shadow Stack is enabled. */
testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
jz L(skip_ssp)
# endif
/* Check and adjust the Shadow-Stack-Pointer. */
xorl %edx, %edx
/* Get the current ssp. */
rdsspd %edx
/* And compare it with the saved ssp value. */
subl SHADOW_STACK_POINTER_OFFSET(%ecx), %edx
je L(skip_ssp)
/* Count the number of frames to adjust and adjust it
with incssp instruction. The instruction can adjust
the ssp by [0..255] value only thus use a loop if
the number of frames is bigger than 255. */
negl %edx
shrl $2, %edx
/* NB: We saved Shadow-Stack-Pointer of setjmp. Since we are
restoring Shadow-Stack-Pointer of setjmp's caller, we
need to unwind shadow stack by one more frame. */
addl $1, %edx
movl $255, %ebx
L(loop):
cmpl %ebx, %edx
cmovb %edx, %ebx
incsspd %ebx
subl %ebx, %edx
ja L(loop)
L(skip_ssp):
# endif
/* Save the return address now. */ /* Save the return address now. */
movl (JB_PC*4)(%ecx), %edx movl (JB_PC*4)(%ecx), %edx
LIBC_PROBE (longjmp, 3, 4@%ecx, -4@%eax, 4@%edx) LIBC_PROBE (longjmp, 3, 4@%ecx, -4@%eax, 4@%edx)

25
sysdeps/i386/add_n.S
View File

@ -40,13 +40,6 @@ ENTRY (__mpn_add_n)
cfi_rel_offset (esi, 0) cfi_rel_offset (esi, 0)
movl S2(%esp),%edx movl S2(%esp),%edx
movl SIZE(%esp),%ecx movl SIZE(%esp),%ecx
#if IBT_ENABLED
pushl %ebx
cfi_adjust_cfa_offset (4)
cfi_rel_offset (ebx, 0)
#endif
movl %ecx,%eax movl %ecx,%eax
shrl $3,%ecx /* compute count for unrolled loop */ shrl $3,%ecx /* compute count for unrolled loop */
negl %eax negl %eax
@ -58,9 +51,6 @@ ENTRY (__mpn_add_n)
subl %eax,%esi /* ... by a constant when we ... */ subl %eax,%esi /* ... by a constant when we ... */
subl %eax,%edx /* ... enter the loop */ subl %eax,%edx /* ... enter the loop */
shrl $2,%eax /* restore previous value */ shrl $2,%eax /* restore previous value */
#if IBT_ENABLED
leal -4(,%eax,4),%ebx /* Count for 4-byte endbr32 */
#endif
#ifdef PIC #ifdef PIC
/* Calculate start address in loop for PIC. Due to limitations in some /* Calculate start address in loop for PIC. Due to limitations in some
assemblers, Loop-L0-3 cannot be put into the leal */ assemblers, Loop-L0-3 cannot be put into the leal */
@ -74,40 +64,30 @@ L(0): leal (%eax,%eax,8),%eax
#else #else
/* Calculate start address in loop for non-PIC. */ /* Calculate start address in loop for non-PIC. */
leal (L(oop) - 3)(%eax,%eax,8),%eax leal (L(oop) - 3)(%eax,%eax,8),%eax
#endif
#if IBT_ENABLED
addl %ebx,%eax /* Adjust for endbr32 */
#endif #endif
jmp *%eax /* jump into loop */ jmp *%eax /* jump into loop */
ALIGN (3) ALIGN (3)
L(oop): movl (%esi),%eax L(oop): movl (%esi),%eax
adcl (%edx),%eax adcl (%edx),%eax
movl %eax,(%edi) movl %eax,(%edi)
_CET_ENDBR
movl 4(%esi),%eax movl 4(%esi),%eax
adcl 4(%edx),%eax adcl 4(%edx),%eax
movl %eax,4(%edi) movl %eax,4(%edi)
_CET_ENDBR
movl 8(%esi),%eax movl 8(%esi),%eax
adcl 8(%edx),%eax adcl 8(%edx),%eax
movl %eax,8(%edi) movl %eax,8(%edi)
_CET_ENDBR
movl 12(%esi),%eax movl 12(%esi),%eax
adcl 12(%edx),%eax adcl 12(%edx),%eax
movl %eax,12(%edi) movl %eax,12(%edi)
_CET_ENDBR
movl 16(%esi),%eax movl 16(%esi),%eax
adcl 16(%edx),%eax adcl 16(%edx),%eax
movl %eax,16(%edi) movl %eax,16(%edi)
_CET_ENDBR
movl 20(%esi),%eax movl 20(%esi),%eax
adcl 20(%edx),%eax adcl 20(%edx),%eax
movl %eax,20(%edi) movl %eax,20(%edi)
_CET_ENDBR
movl 24(%esi),%eax movl 24(%esi),%eax
adcl 24(%edx),%eax adcl 24(%edx),%eax
movl %eax,24(%edi) movl %eax,24(%edi)
_CET_ENDBR
movl 28(%esi),%eax movl 28(%esi),%eax
adcl 28(%edx),%eax adcl 28(%edx),%eax
movl %eax,28(%edi) movl %eax,28(%edi)
@ -120,11 +100,6 @@ L(oop): movl (%esi),%eax
sbbl %eax,%eax sbbl %eax,%eax
negl %eax negl %eax
#if IBT_ENABLED
popl %ebx
cfi_adjust_cfa_offset (-4)
cfi_restore (ebx)
#endif
popl %esi popl %esi
cfi_adjust_cfa_offset (-4) cfi_adjust_cfa_offset (-4)
cfi_restore (esi) cfi_restore (esi)

21
sysdeps/i386/bsd-_setjmp.S
View File

@ -23,18 +23,12 @@
#include <sysdep.h> #include <sysdep.h>
#include <pointer_guard.h> #include <pointer_guard.h>
#include <jmpbuf-offsets.h> #include <jmpbuf-offsets.h>
#include <jmp_buf-ssp.h>
#include <stap-probe.h> #include <stap-probe.h>
#define PARMS 4 /* no space for saved regs */ #define PARMS 4 /* no space for saved regs */
#define JMPBUF PARMS #define JMPBUF PARMS
#define SIGMSK JMPBUF+4 #define SIGMSK JMPBUF+4
/* Don't save shadow stack register if shadow stack isn't enabled. */
#if !SHSTK_ENABLED
# undef SHADOW_STACK_POINTER_OFFSET
#endif
ENTRY (_setjmp) ENTRY (_setjmp)
xorl %eax, %eax xorl %eax, %eax
@ -58,21 +52,6 @@ ENTRY (_setjmp)
movl %ebp, (JB_BP*4)(%edx) /* Save caller's frame pointer. */ movl %ebp, (JB_BP*4)(%edx) /* Save caller's frame pointer. */
movl %eax, JB_SIZE(%edx) /* No signal mask set. */ movl %eax, JB_SIZE(%edx) /* No signal mask set. */
#ifdef SHADOW_STACK_POINTER_OFFSET
# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
/* Check if Shadow Stack is enabled. */
testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
jz L(skip_ssp)
# else
xorl %ecx, %ecx
# endif
/* Get the current Shadow-Stack-Pointer and save it. */
rdsspd %ecx
movl %ecx, SHADOW_STACK_POINTER_OFFSET(%edx)
# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
L(skip_ssp):
# endif
#endif
ret ret
END (_setjmp) END (_setjmp)
libc_hidden_def (_setjmp) libc_hidden_def (_setjmp)

21
sysdeps/i386/bsd-setjmp.S
View File

@ -23,18 +23,12 @@
#include <sysdep.h> #include <sysdep.h>
#include <pointer_guard.h> #include <pointer_guard.h>
#include <jmpbuf-offsets.h> #include <jmpbuf-offsets.h>
#include <jmp_buf-ssp.h>
#include <stap-probe.h> #include <stap-probe.h>
#define PARMS 4 /* no space for saved regs */ #define PARMS 4 /* no space for saved regs */
#define JMPBUF PARMS #define JMPBUF PARMS
#define SIGMSK JMPBUF+4 #define SIGMSK JMPBUF+4
/* Don't save shadow stack register if shadow stack isn't enabled. */
#if !SHSTK_ENABLED
# undef SHADOW_STACK_POINTER_OFFSET
#endif
ENTRY (setjmp) ENTRY (setjmp)
/* Note that we have to use a non-exported symbol in the next /* Note that we have to use a non-exported symbol in the next
jump since otherwise gas will emit it as a jump through the jump since otherwise gas will emit it as a jump through the
@ -58,21 +52,6 @@ ENTRY (setjmp)
#endif #endif
movl %ecx, (JB_PC*4)(%eax) movl %ecx, (JB_PC*4)(%eax)
movl %ebp, (JB_BP*4)(%eax) /* Save caller's frame pointer. */ movl %ebp, (JB_BP*4)(%eax) /* Save caller's frame pointer. */
#ifdef SHADOW_STACK_POINTER_OFFSET
# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
/* Check if Shadow Stack is enabled. */
testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
jz L(skip_ssp)
# else
xorl %ecx, %ecx
# endif
/* Get the current Shadow-Stack-Pointer and save it. */
rdsspd %ecx
movl %ecx, SHADOW_STACK_POINTER_OFFSET(%eax)
# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
L(skip_ssp):
# endif
#endif
/* Call __sigjmp_save. */ /* Call __sigjmp_save. */
pushl $1 pushl $1

2
sysdeps/i386/crti.S
View File

@ -61,7 +61,6 @@
.hidden _init .hidden _init
.type _init, @function .type _init, @function
_init: _init:
_CET_ENDBR
pushl %ebx pushl %ebx
/* Maintain 16-byte stack alignment for called functions. */ /* Maintain 16-byte stack alignment for called functions. */
subl $8, %esp subl $8, %esp
@ -82,7 +81,6 @@ _init:
.hidden _fini .hidden _fini
.type _fini, @function .type _fini, @function
_fini: _fini:
_CET_ENDBR
pushl %ebx pushl %ebx
subl $8, %esp subl $8, %esp
LOAD_PIC_REG (bx) LOAD_PIC_REG (bx)

3
sysdeps/i386/dl-tlsdesc.S
View File

@ -37,7 +37,6 @@
cfi_startproc cfi_startproc
.align 16 .align 16
_dl_tlsdesc_return: _dl_tlsdesc_return:
_CET_ENDBR
movl 4(%eax), %eax movl 4(%eax), %eax
ret ret
cfi_endproc cfi_endproc
@ -59,7 +58,6 @@ _dl_tlsdesc_return:
cfi_startproc cfi_startproc
.align 16 .align 16
_dl_tlsdesc_undefweak: _dl_tlsdesc_undefweak:
_CET_ENDBR
movl 4(%eax), %eax movl 4(%eax), %eax
subl %gs:0, %eax subl %gs:0, %eax
ret ret
@ -101,7 +99,6 @@ _dl_tlsdesc_dynamic (struct tlsdesc *tdp)
cfi_startproc cfi_startproc
.align 16 .align 16
_dl_tlsdesc_dynamic: _dl_tlsdesc_dynamic:
_CET_ENDBR
/* Like all TLS resolvers, preserve call-clobbered registers. /* Like all TLS resolvers, preserve call-clobbered registers.
We need two scratch regs anyway. */ We need two scratch regs anyway. */
subl $28, %esp subl $28, %esp

4
sysdeps/i386/dl-trampoline.S
View File

@ -26,7 +26,6 @@
.align 16 .align 16
_dl_runtime_resolve: _dl_runtime_resolve:
cfi_adjust_cfa_offset (8) cfi_adjust_cfa_offset (8)
_CET_ENDBR
pushl %eax # Preserve registers otherwise clobbered. pushl %eax # Preserve registers otherwise clobbered.
cfi_adjust_cfa_offset (4) cfi_adjust_cfa_offset (4)
pushl %ecx pushl %ecx
@ -53,7 +52,6 @@ _dl_runtime_resolve:
.align 16 .align 16
_dl_runtime_resolve_shstk: _dl_runtime_resolve_shstk:
cfi_adjust_cfa_offset (8) cfi_adjust_cfa_offset (8)
_CET_ENDBR
pushl %eax # Preserve registers otherwise clobbered. pushl %eax # Preserve registers otherwise clobbered.
cfi_adjust_cfa_offset (4) cfi_adjust_cfa_offset (4)
pushl %edx pushl %edx
@ -78,7 +76,6 @@ _dl_runtime_resolve_shstk:
.align 16 .align 16
_dl_runtime_profile_shstk: _dl_runtime_profile_shstk:
cfi_adjust_cfa_offset (8) cfi_adjust_cfa_offset (8)
_CET_ENDBR
pushl %esp pushl %esp
cfi_adjust_cfa_offset (4) cfi_adjust_cfa_offset (4)
addl $8, (%esp) # Account for the pushed PLT data addl $8, (%esp) # Account for the pushed PLT data
@ -123,7 +120,6 @@ _dl_runtime_profile_shstk:
.align 16 .align 16
_dl_runtime_profile: _dl_runtime_profile:
cfi_adjust_cfa_offset (8) cfi_adjust_cfa_offset (8)
_CET_ENDBR
pushl %esp pushl %esp
cfi_adjust_cfa_offset (4) cfi_adjust_cfa_offset (4)
addl $8, (%esp) # Account for the pushed PLT data addl $8, (%esp) # Account for the pushed PLT data

2
sysdeps/i386/i386-mcount.S
View File

@ -29,7 +29,6 @@
.type C_SYMBOL_NAME(_mcount), @function .type C_SYMBOL_NAME(_mcount), @function
.align ALIGNARG(4) .align ALIGNARG(4)
C_LABEL(_mcount) C_LABEL(_mcount)
_CET_ENDBR
/* Save the caller-clobbered registers. */ /* Save the caller-clobbered registers. */
pushl %eax pushl %eax
pushl %ecx pushl %ecx
@ -58,7 +57,6 @@ weak_alias (_mcount, mcount)
.type C_SYMBOL_NAME(__fentry__), @function .type C_SYMBOL_NAME(__fentry__), @function
.align ALIGNARG(4) .align ALIGNARG(4)
C_LABEL(__fentry__) C_LABEL(__fentry__)
_CET_ENDBR
/* Save the caller-clobbered registers. */ /* Save the caller-clobbered registers. */
pushl %eax pushl %eax
pushl %ecx pushl %ecx

25
sysdeps/i386/i686/add_n.S
View File

@ -44,13 +44,6 @@ ENTRY (__mpn_add_n)
cfi_rel_offset (esi, 0) cfi_rel_offset (esi, 0)
movl S2(%esp),%edx movl S2(%esp),%edx
movl SIZE(%esp),%ecx movl SIZE(%esp),%ecx
#if IBT_ENABLED
pushl %ebx
cfi_adjust_cfa_offset (4)
cfi_rel_offset (ebx, 0)
#endif
movl %ecx,%eax movl %ecx,%eax
shrl $3,%ecx /* compute count for unrolled loop */ shrl $3,%ecx /* compute count for unrolled loop */
negl %eax negl %eax
@ -62,9 +55,6 @@ ENTRY (__mpn_add_n)
subl %eax,%esi /* ... by a constant when we ... */ subl %eax,%esi /* ... by a constant when we ... */
subl %eax,%edx /* ... enter the loop */ subl %eax,%edx /* ... enter the loop */
shrl $2,%eax /* restore previous value */ shrl $2,%eax /* restore previous value */
#if IBT_ENABLED
leal -4(,%eax,4),%ebx /* Count for 4-byte endbr32 */
#endif
#ifdef PIC #ifdef PIC
/* Calculate start address in loop for PIC. */ /* Calculate start address in loop for PIC. */
leal (L(oop)-L(0)-3)(%eax,%eax,8),%eax leal (L(oop)-L(0)-3)(%eax,%eax,8),%eax
@ -73,40 +63,30 @@ L(0):
#else #else
/* Calculate start address in loop for non-PIC. */ /* Calculate start address in loop for non-PIC. */
leal (L(oop) - 3)(%eax,%eax,8),%eax leal (L(oop) - 3)(%eax,%eax,8),%eax
#endif
#if IBT_ENABLED
addl %ebx,%eax /* Adjust for endbr32 */
#endif #endif
jmp *%eax /* jump into loop */ jmp *%eax /* jump into loop */
ALIGN (3) ALIGN (3)
L(oop): movl (%esi),%eax L(oop): movl (%esi),%eax
adcl (%edx),%eax adcl (%edx),%eax
movl %eax,(%edi) movl %eax,(%edi)
_CET_ENDBR
movl 4(%esi),%eax movl 4(%esi),%eax
adcl 4(%edx),%eax adcl 4(%edx),%eax
movl %eax,4(%edi) movl %eax,4(%edi)
_CET_ENDBR
movl 8(%esi),%eax movl 8(%esi),%eax
adcl 8(%edx),%eax adcl 8(%edx),%eax
movl %eax,8(%edi) movl %eax,8(%edi)
_CET_ENDBR
movl 12(%esi),%eax movl 12(%esi),%eax
adcl 12(%edx),%eax adcl 12(%edx),%eax
movl %eax,12(%edi) movl %eax,12(%edi)
_CET_ENDBR
movl 16(%esi),%eax movl 16(%esi),%eax
adcl 16(%edx),%eax adcl 16(%edx),%eax
movl %eax,16(%edi) movl %eax,16(%edi)
_CET_ENDBR
movl 20(%esi),%eax movl 20(%esi),%eax
adcl 20(%edx),%eax adcl 20(%edx),%eax
movl %eax,20(%edi) movl %eax,20(%edi)
_CET_ENDBR
movl 24(%esi),%eax movl 24(%esi),%eax
adcl 24(%edx),%eax adcl 24(%edx),%eax
movl %eax,24(%edi) movl %eax,24(%edi)
_CET_ENDBR
movl 28(%esi),%eax movl 28(%esi),%eax
adcl 28(%edx),%eax adcl 28(%edx),%eax
movl %eax,28(%edi) movl %eax,28(%edi)
@ -119,11 +99,6 @@ L(oop): movl (%esi),%eax
sbbl %eax,%eax sbbl %eax,%eax
negl %eax negl %eax
#if IBT_ENABLED
popl %ebx
cfi_adjust_cfa_offset (-4)
cfi_restore (ebx)
#endif
popl %esi popl %esi
cfi_adjust_cfa_offset (-4) cfi_adjust_cfa_offset (-4)
cfi_restore (esi) cfi_restore (esi)

4
sysdeps/i386/i686/memcmp.S
View File

@ -80,7 +80,7 @@ L(not_1):
LOAD_JUMP_TABLE_ENTRY (L(table_32bytes), %ecx) LOAD_JUMP_TABLE_ENTRY (L(table_32bytes), %ecx)
addl %ecx, %edx addl %ecx, %edx
addl %ecx, %esi addl %ecx, %esi
_CET_NOTRACK jmp *%ebx jmp *%ebx
ALIGN (4) ALIGN (4)
L(28bytes): L(28bytes):
@ -326,7 +326,7 @@ L(32bytesormore):
LOAD_JUMP_TABLE_ENTRY (L(table_32bytes), %ecx) LOAD_JUMP_TABLE_ENTRY (L(table_32bytes), %ecx)
addl %ecx, %edx addl %ecx, %edx
addl %ecx, %esi addl %ecx, %esi
_CET_NOTRACK jmp *%ebx jmp *%ebx
L(load_ecx_28): L(load_ecx_28):
addl $0x4, %edx addl $0x4, %edx

4
sysdeps/i386/i686/multiarch/memcmp-sse4.S
View File

@ -58,7 +58,7 @@
absolute address. */ \ absolute address. */ \
addl (%ebx,INDEX,SCALE), %ebx; \ addl (%ebx,INDEX,SCALE), %ebx; \
/* We loaded the jump table and adjusted EDX/ESI. Go. */ \ /* We loaded the jump table and adjusted EDX/ESI. Go. */ \
_CET_NOTRACK jmp *%ebx jmp *%ebx
# else # else
# define JMPTBL(I, B) I # define JMPTBL(I, B) I
@ -66,7 +66,7 @@
jump table with relative offsets. INDEX is a register contains the jump table with relative offsets. INDEX is a register contains the
index into the jump table. SCALE is the scale of INDEX. */ index into the jump table. SCALE is the scale of INDEX. */
# define BRANCH_TO_JMPTBL_ENTRY(TABLE, INDEX, SCALE) \ # define BRANCH_TO_JMPTBL_ENTRY(TABLE, INDEX, SCALE) \
_CET_NOTRACK jmp *TABLE(,INDEX,SCALE) jmp *TABLE(,INDEX,SCALE)
# endif # endif

8
sysdeps/i386/i686/multiarch/memcpy-ssse3-rep.S
View File

@ -64,7 +64,7 @@
absolute address. */ \ absolute address. */ \
addl (%ebx,INDEX,SCALE), %ebx; \ addl (%ebx,INDEX,SCALE), %ebx; \
/* We loaded the jump table. Go. */ \ /* We loaded the jump table. Go. */ \
_CET_NOTRACK jmp *%ebx jmp *%ebx
# define BRANCH_TO_JMPTBL_ENTRY_VALUE(TABLE) \ # define BRANCH_TO_JMPTBL_ENTRY_VALUE(TABLE) \
addl $(TABLE - .), %ebx addl $(TABLE - .), %ebx
@ -72,7 +72,7 @@
# define BRANCH_TO_JMPTBL_ENTRY_TAIL(TABLE, INDEX, SCALE) \ # define BRANCH_TO_JMPTBL_ENTRY_TAIL(TABLE, INDEX, SCALE) \
addl (%ebx,INDEX,SCALE), %ebx; \ addl (%ebx,INDEX,SCALE), %ebx; \
/* We loaded the jump table. Go. */ \ /* We loaded the jump table. Go. */ \
_CET_NOTRACK jmp *%ebx jmp *%ebx
#else #else
# define PARMS 4 # define PARMS 4
# define ENTRANCE # define ENTRANCE
@ -84,12 +84,12 @@
absolute offsets. INDEX is a register contains the index into the absolute offsets. INDEX is a register contains the index into the
jump table. SCALE is the scale of INDEX. */ jump table. SCALE is the scale of INDEX. */
# define BRANCH_TO_JMPTBL_ENTRY(TABLE, INDEX, SCALE) \ # define BRANCH_TO_JMPTBL_ENTRY(TABLE, INDEX, SCALE) \
_CET_NOTRACK jmp *TABLE(,INDEX,SCALE) jmp *TABLE(,INDEX,SCALE)
# define BRANCH_TO_JMPTBL_ENTRY_VALUE(TABLE) # define BRANCH_TO_JMPTBL_ENTRY_VALUE(TABLE)
# define BRANCH_TO_JMPTBL_ENTRY_TAIL(TABLE, INDEX, SCALE) \ # define BRANCH_TO_JMPTBL_ENTRY_TAIL(TABLE, INDEX, SCALE) \
_CET_NOTRACK jmp *TABLE(,INDEX,SCALE) jmp *TABLE(,INDEX,SCALE)
#endif #endif
.section .text.ssse3,"ax",@progbits .section .text.ssse3,"ax",@progbits

4
sysdeps/i386/i686/multiarch/memcpy-ssse3.S
View File

@ -64,7 +64,7 @@
absolute address. */ \ absolute address. */ \
addl (%ebx, INDEX, SCALE), %ebx; \ addl (%ebx, INDEX, SCALE), %ebx; \
/* We loaded the jump table. Go. */ \ /* We loaded the jump table. Go. */ \
_CET_NOTRACK jmp *%ebx jmp *%ebx
# else # else
# define PARMS 4 # define PARMS 4
@ -78,7 +78,7 @@
jump table. SCALE is the scale of INDEX. */ jump table. SCALE is the scale of INDEX. */
# define BRANCH_TO_JMPTBL_ENTRY(TABLE, INDEX, SCALE) \ # define BRANCH_TO_JMPTBL_ENTRY(TABLE, INDEX, SCALE) \
_CET_NOTRACK jmp *TABLE(, INDEX, SCALE) jmp *TABLE(, INDEX, SCALE)
# endif # endif
.section .text.ssse3,"ax",@progbits .section .text.ssse3,"ax",@progbits

4
sysdeps/i386/i686/multiarch/memset-sse2-rep.S
View File

@ -56,7 +56,7 @@
add (%ebx,%ecx,4), %ebx; \ add (%ebx,%ecx,4), %ebx; \
add %ecx, %edx; \ add %ecx, %edx; \
/* We loaded the jump table and adjusted EDX. Go. */ \ /* We loaded the jump table and adjusted EDX. Go. */ \
_CET_NOTRACK jmp *%ebx jmp *%ebx
#else #else
# define ENTRANCE # define ENTRANCE
# define RETURN_END ret # define RETURN_END ret
@ -68,7 +68,7 @@
absolute offsets. */ absolute offsets. */
# define BRANCH_TO_JMPTBL_ENTRY(TABLE) \ # define BRANCH_TO_JMPTBL_ENTRY(TABLE) \
add %ecx, %edx; \ add %ecx, %edx; \
_CET_NOTRACK jmp *TABLE(,%ecx,4) jmp *TABLE(,%ecx,4)
#endif #endif
.section .text.sse2,"ax",@progbits .section .text.sse2,"ax",@progbits

4
sysdeps/i386/i686/multiarch/memset-sse2.S
View File

@ -56,7 +56,7 @@
add (%ebx,%ecx,4), %ebx; \ add (%ebx,%ecx,4), %ebx; \
add %ecx, %edx; \ add %ecx, %edx; \
/* We loaded the jump table and adjusted EDX. Go. */ \ /* We loaded the jump table and adjusted EDX. Go. */ \
_CET_NOTRACK jmp *%ebx jmp *%ebx
#else #else
# define ENTRANCE # define ENTRANCE
# define RETURN_END ret # define RETURN_END ret
@ -68,7 +68,7 @@
absolute offsets. */ absolute offsets. */
# define BRANCH_TO_JMPTBL_ENTRY(TABLE) \ # define BRANCH_TO_JMPTBL_ENTRY(TABLE) \
add %ecx, %edx; \ add %ecx, %edx; \
_CET_NOTRACK jmp *TABLE(,%ecx,4) jmp *TABLE(,%ecx,4)
#endif #endif
.section .text.sse2,"ax",@progbits .section .text.sse2,"ax",@progbits

4
sysdeps/i386/i686/multiarch/strcat-sse2.S
View File

@ -49,7 +49,7 @@
absolute address. */ \ absolute address. */ \
addl (%ecx,INDEX,SCALE), %ecx; \ addl (%ecx,INDEX,SCALE), %ecx; \
/* We loaded the jump table and adjusted ECX. Go. */ \ /* We loaded the jump table and adjusted ECX. Go. */ \
_CET_NOTRACK jmp *%ecx jmp *%ecx
# else # else
# define JMPTBL(I, B) I # define JMPTBL(I, B) I
@ -58,7 +58,7 @@
jump table. SCALE is the scale of INDEX. */ jump table. SCALE is the scale of INDEX. */
# define BRANCH_TO_JMPTBL_ENTRY(TABLE, INDEX, SCALE) \ # define BRANCH_TO_JMPTBL_ENTRY(TABLE, INDEX, SCALE) \
_CET_NOTRACK jmp *TABLE(,INDEX,SCALE) jmp *TABLE(,INDEX,SCALE)
# endif # endif
# ifndef STRCAT # ifndef STRCAT

4
sysdeps/i386/i686/multiarch/strcpy-sse2.S
View File

@ -64,7 +64,7 @@
absolute address. */ \ absolute address. */ \
addl (%ecx,INDEX,SCALE), %ecx; \ addl (%ecx,INDEX,SCALE), %ecx; \
/* We loaded the jump table and adjusted ECX. Go. */ \ /* We loaded the jump table and adjusted ECX. Go. */ \
_CET_NOTRACK jmp *%ecx jmp *%ecx
# else # else
# define JMPTBL(I, B) I # define JMPTBL(I, B) I
@ -73,7 +73,7 @@
jump table. SCALE is the scale of INDEX. */ jump table. SCALE is the scale of INDEX. */
# define BRANCH_TO_JMPTBL_ENTRY(TABLE, INDEX, SCALE) \ # define BRANCH_TO_JMPTBL_ENTRY(TABLE, INDEX, SCALE) \
_CET_NOTRACK jmp *TABLE(,INDEX,SCALE) jmp *TABLE(,INDEX,SCALE)
# endif # endif
.text .text

21
sysdeps/i386/setjmp.S
View File

@ -19,7 +19,6 @@
#include <sysdep.h> #include <sysdep.h>
#include <pointer_guard.h> #include <pointer_guard.h>
#include <jmpbuf-offsets.h> #include <jmpbuf-offsets.h>
#include <jmp_buf-ssp.h>
#include <asm-syntax.h> #include <asm-syntax.h>
#include <stap-probe.h> #include <stap-probe.h>
@ -27,11 +26,6 @@
#define JMPBUF PARMS #define JMPBUF PARMS
#define SIGMSK JMPBUF+4 #define SIGMSK JMPBUF+4
/* Don't save shadow stack register if shadow stack isn't enabled. */
#if !SHSTK_ENABLED
# undef SHADOW_STACK_POINTER_OFFSET
#endif
ENTRY (__sigsetjmp) ENTRY (__sigsetjmp)
movl JMPBUF(%esp), %eax movl JMPBUF(%esp), %eax
@ -53,21 +47,6 @@ ENTRY (__sigsetjmp)
movl %ecx, (JB_PC*4)(%eax) movl %ecx, (JB_PC*4)(%eax)
movl %ebp, (JB_BP*4)(%eax) /* Save caller's frame pointer. */ movl %ebp, (JB_BP*4)(%eax) /* Save caller's frame pointer. */
#ifdef SHADOW_STACK_POINTER_OFFSET
# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
/* Check if Shadow Stack is enabled. */
testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
jz L(skip_ssp)
# else
xorl %ecx, %ecx
# endif
/* Get the current Shadow-Stack-Pointer and save it. */
rdsspd %ecx
movl %ecx, SHADOW_STACK_POINTER_OFFSET(%eax)
# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
L(skip_ssp):
# endif
#endif
#if IS_IN (rtld) #if IS_IN (rtld)
/* In ld.so we never save the signal mask. */ /* In ld.so we never save the signal mask. */
xorl %eax, %eax xorl %eax, %eax

1
sysdeps/i386/start.S
View File

@ -132,7 +132,6 @@ ENTRY (_start)
#if defined PIC && !defined SHARED #if defined PIC && !defined SHARED
__wrap_main: __wrap_main:
_CET_ENDBR
jmp main@PLT jmp main@PLT
#endif #endif
END (_start) END (_start)

25
sysdeps/i386/sub_n.S
View File

@ -40,13 +40,6 @@ ENTRY (__mpn_sub_n)
cfi_rel_offset (esi, 0) cfi_rel_offset (esi, 0)
movl S2(%esp),%edx movl S2(%esp),%edx
movl SIZE(%esp),%ecx movl SIZE(%esp),%ecx
#if IBT_ENABLED
pushl %ebx
cfi_adjust_cfa_offset (4)
cfi_rel_offset (ebx, 0)
#endif
movl %ecx,%eax movl %ecx,%eax
shrl $3,%ecx /* compute count for unrolled loop */ shrl $3,%ecx /* compute count for unrolled loop */
negl %eax negl %eax
@ -58,9 +51,6 @@ ENTRY (__mpn_sub_n)
subl %eax,%esi /* ... by a constant when we ... */ subl %eax,%esi /* ... by a constant when we ... */
subl %eax,%edx /* ... enter the loop */ subl %eax,%edx /* ... enter the loop */
shrl $2,%eax /* restore previous value */ shrl $2,%eax /* restore previous value */
#if defined __CET__ && (__CET__ & 1) != 0
leal -4(,%eax,4),%ebx /* Count for 4-byte endbr32 */
#endif
#ifdef PIC #ifdef PIC
/* Calculate start address in loop for PIC. Due to limitations in some /* Calculate start address in loop for PIC. Due to limitations in some
assemblers, Loop-L0-3 cannot be put into the leal */ assemblers, Loop-L0-3 cannot be put into the leal */
@ -74,40 +64,30 @@ L(0): leal (%eax,%eax,8),%eax
#else #else
/* Calculate start address in loop for non-PIC. */ /* Calculate start address in loop for non-PIC. */
leal (L(oop) - 3)(%eax,%eax,8),%eax leal (L(oop) - 3)(%eax,%eax,8),%eax
#endif
#if defined __CET__ && (__CET__ & 1) != 0
addl %ebx,%eax /* Adjust for endbr32 */
#endif #endif
jmp *%eax /* jump into loop */ jmp *%eax /* jump into loop */
ALIGN (3) ALIGN (3)
L(oop): movl (%esi),%eax L(oop): movl (%esi),%eax
sbbl (%edx),%eax sbbl (%edx),%eax
movl %eax,(%edi) movl %eax,(%edi)
_CET_ENDBR
movl 4(%esi),%eax movl 4(%esi),%eax
sbbl 4(%edx),%eax sbbl 4(%edx),%eax
movl %eax,4(%edi) movl %eax,4(%edi)
_CET_ENDBR
movl 8(%esi),%eax movl 8(%esi),%eax
sbbl 8(%edx),%eax sbbl 8(%edx),%eax
movl %eax,8(%edi) movl %eax,8(%edi)
_CET_ENDBR
movl 12(%esi),%eax movl 12(%esi),%eax
sbbl 12(%edx),%eax sbbl 12(%edx),%eax
movl %eax,12(%edi) movl %eax,12(%edi)
_CET_ENDBR
movl 16(%esi),%eax movl 16(%esi),%eax
sbbl 16(%edx),%eax sbbl 16(%edx),%eax
movl %eax,16(%edi) movl %eax,16(%edi)
_CET_ENDBR
movl 20(%esi),%eax movl 20(%esi),%eax
sbbl 20(%edx),%eax sbbl 20(%edx),%eax
movl %eax,20(%edi) movl %eax,20(%edi)
_CET_ENDBR
movl 24(%esi),%eax movl 24(%esi),%eax
sbbl 24(%edx),%eax sbbl 24(%edx),%eax
movl %eax,24(%edi) movl %eax,24(%edi)
_CET_ENDBR
movl 28(%esi),%eax movl 28(%esi),%eax
sbbl 28(%edx),%eax sbbl 28(%edx),%eax
movl %eax,28(%edi) movl %eax,28(%edi)
@ -120,11 +100,6 @@ L(oop): movl (%esi),%eax
sbbl %eax,%eax sbbl %eax,%eax
negl %eax negl %eax
#if defined __CET__ && (__CET__ & 1) != 0
popl %ebx
cfi_adjust_cfa_offset (-4)
cfi_restore (ebx)
#endif
popl %esi popl %esi
cfi_adjust_cfa_offset (-4) cfi_adjust_cfa_offset (-4)
cfi_restore (esi) cfi_restore (esi)

11
sysdeps/i386/sysdep.h
View File

@ -18,6 +18,8 @@
#include <sysdeps/x86/sysdep.h> #include <sysdeps/x86/sysdep.h>
#define CET_ENABLED 0
/* It is desirable that the names of PIC thunks match those used by /* It is desirable that the names of PIC thunks match those used by
GCC so that multiple copies are eliminated by the linker. Because GCC so that multiple copies are eliminated by the linker. Because
GCC 4.6 and earlier use __i686 in the names, it is necessary to GCC 4.6 and earlier use __i686 in the names, it is necessary to
@ -37,6 +39,15 @@
/* Syntactic details of assembler. */ /* Syntactic details of assembler. */
/* 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; \
CALL_MCOUNT
/* If compiled for profiling, call `mcount' at the start of each function. */ /* If compiled for profiling, call `mcount' at the start of each function. */
#ifdef PROF #ifdef PROF
/* The mcount code relies on a normal frame pointer being on the stack /* The mcount code relies on a normal frame pointer being on the stack

37
sysdeps/unix/sysv/linux/i386/____longjmp_chk.S
View File

@ -18,14 +18,9 @@
#include <sysdep.h> #include <sysdep.h>
#include <pointer_guard.h> #include <pointer_guard.h>
#include <jmpbuf-offsets.h> #include <jmpbuf-offsets.h>
#include <jmp_buf-ssp.h>
#include <asm-syntax.h> #include <asm-syntax.h>
#include <stap-probe.h> #include <stap-probe.h>
/* Don't restore shadow stack register if shadow stack isn't enabled. */
#if !SHSTK_ENABLED
# undef SHADOW_STACK_POINTER_OFFSET
#endif
.section .rodata.str1.1,"aMS",@progbits,1 .section .rodata.str1.1,"aMS",@progbits,1
.type longjmp_msg,@object .type longjmp_msg,@object
@ -52,38 +47,6 @@ longjmp_msg:
ENTRY (____longjmp_chk) ENTRY (____longjmp_chk)
movl 4(%esp), %ecx /* User's jmp_buf in %ecx. */ movl 4(%esp), %ecx /* User's jmp_buf in %ecx. */
#ifdef SHADOW_STACK_POINTER_OFFSET
# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
/* Check if Shadow Stack is enabled. */
testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
jz L(skip_ssp)
# else
xorl %edx, %edx
# endif
/* Check and adjust the Shadow-Stack-Pointer. */
rdsspd %edx
/* And compare it with the saved ssp value. */
subl SHADOW_STACK_POINTER_OFFSET(%ecx), %edx
je L(skip_ssp)
/* Count the number of frames to adjust and adjust it
with incssp instruction. The instruction can adjust
the ssp by [0..255] value only thus use a loop if
the number of frames is bigger than 255. */
negl %edx
shrl $2, %edx
/* NB: We saved Shadow-Stack-Pointer of setjmp. Since we are
restoring Shadow-Stack-Pointer of setjmp's caller, we
need to unwind shadow stack by one more frame. */
addl $1, %edx
movl $255, %ebx
L(loop):
cmpl %ebx, %edx
cmovb %edx, %ebx
incsspd %ebx
subl %ebx, %edx
ja L(loop)
L(skip_ssp):
#endif
/* Save the return address now. */ /* Save the return address now. */
movl (JB_PC*4)(%ecx), %edx movl (JB_PC*4)(%ecx), %edx
/* Get the stack pointer. */ /* Get the stack pointer. */

56
sysdeps/unix/sysv/linux/i386/getcontext.S
View File

@ -17,7 +17,6 @@
<https://www.gnu.org/licenses/>. */ <https://www.gnu.org/licenses/>. */
#include <sysdep.h> #include <sysdep.h>
#include <asm/prctl.h>
#include "ucontext_i.h" #include "ucontext_i.h"
@ -42,61 +41,6 @@ ENTRY(__getcontext)
movw %fs, %dx movw %fs, %dx
movl %edx, oFS(%eax) movl %edx, oFS(%eax)
#if SHSTK_ENABLED
/* Check if shadow stack is enabled. */
testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
jz L(no_shstk)
/* Save EAX in EDX. */
movl %eax, %edx
xorl %eax, %eax
cmpl %gs:SSP_BASE_OFFSET, %eax
jnz L(shadow_stack_bound_recorded)
/* Save EBX in the first scratch register slot. */
movl %ebx, oSCRATCH1(%edx)
/* Get the base address and size of the default shadow stack
which must be the current shadow stack since nothing has
been recorded yet. */
sub $24, %esp
mov %esp, %ecx
movl $ARCH_CET_STATUS, %ebx
movl $__NR_arch_prctl, %eax
ENTER_KERNEL
testl %eax, %eax
jz L(continue_no_err)
/* This should never happen. */
hlt
L(continue_no_err):
/* Restore EBX from the first scratch register slot. */
movl oSCRATCH1(%edx), %ebx
/* Record the base of the current shadow stack. */
movl 8(%esp), %eax
movl %eax, %gs:SSP_BASE_OFFSET
add $24, %esp
L(shadow_stack_bound_recorded):
/* Load address of the context data structure. */
movl 4(%esp), %eax
/* Get the current shadow stack pointer. */
rdsspd %edx
/* NB: Save the caller's shadow stack so that we can jump back
to the caller directly. */
addl $4, %edx
movl %edx, oSSP(%eax)
/* Save the current shadow stack base in ucontext. */
movl %gs:SSP_BASE_OFFSET, %edx
movl %edx, (oSSP + 4)(%eax)
L(no_shstk):
#endif
/* We have separate floating-point register content memory on the /* We have separate floating-point register content memory on the
stack. We use the __fpregs_mem block in the context. Set the stack. We use the __fpregs_mem block in the context. Set the
links up correctly. */ links up correctly. */

123
sysdeps/unix/sysv/linux/i386/makecontext.S
View File

@ -17,7 +17,6 @@
<https://www.gnu.org/licenses/>. */ <https://www.gnu.org/licenses/>. */
#include <sysdep.h> #include <sysdep.h>
#include <asm/prctl.h>
#include "ucontext_i.h" #include "ucontext_i.h"
@ -68,127 +67,6 @@ ENTRY(__makecontext)
jnz 1b jnz 1b
2: 2:
#if SHSTK_ENABLED
/* Check if Shadow Stack is enabled. */
testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
jz L(skip_ssp)
/* Reload the pointer to ucontext. */
movl 4(%esp), %eax
/* Shadow stack is enabled. We need to allocate a new shadow
stack. */
subl oSS_SP(%eax), %edx
shrl $STACK_SIZE_TO_SHADOW_STACK_SIZE_SHIFT, %edx
/* Align shadow stack size to 8 bytes. */
addl $7, %edx
andl $-8, %edx
/* Store shadow stack size in __ssp[2]. */
movl %edx, (oSSP + 8)(%eax)
/* Save ESI in the second scratch register slot. */
movl %esi, oSCRATCH2(%eax)
/* Save EDI in the third scratch register slot. */
movl %edi, oSCRATCH3(%eax)
/* Save the pointer to ucontext. */
movl %eax, %edi
/* Get the original shadow stack pointer. */
rdsspd %esi
/* Align the saved original shadow stack pointer to the next
8 byte aligned boundary. */
andl $-8, %esi
/* Load the top of the new stack into EDX. */
movl oESP(%eax), %edx
/* We need to terminate the FDE here because the unwinder looks
at ra-1 for unwind information. */
cfi_endproc
/* Swap the original stack pointer with the top of the new
stack. */
xchgl %esp, %edx
/* Add 4 bytes since CALL will push the 4-byte return address
onto stack. */
addl $4, %esp
/* Allocate the new shadow stack. Save EBX in the first scratch
register slot. */
movl %ebx, oSCRATCH1(%eax)
/* CET syscall takes 64-bit sizes. */
subl $16, %esp
movl (oSSP + 8)(%eax), %ecx
movl %ecx, (%esp)
movl $0, 4(%esp)
movl %ecx, 8(%esp)
movl $0, 12(%esp)
movl %esp, %ecx
movl $ARCH_CET_ALLOC_SHSTK, %ebx
movl $__NR_arch_prctl, %eax
ENTER_KERNEL
testl %eax, %eax
jne L(hlt) /* This should never happen. */
/* Copy the base address of the new shadow stack to __ssp[1]. */
movl (%esp), %eax
movl %eax, (oSSP + 4)(%edi)
addl $16, %esp
/* Restore EBX from the first scratch register slot. */
movl oSCRATCH1(%edi), %ebx
/* Get the size of the new shadow stack. */
movl (oSSP + 8)(%edi), %ecx
/* Use the restore stoken to restore the new shadow stack. */
rstorssp -8(%eax, %ecx)
/* Save the restore token at the next 8 byte aligned boundary
on the original shadow stack. */
saveprevssp
/* Push the address of "jmp exitcode" onto the new stack as
well as the new shadow stack. */
call 1f
jmp L(exitcode)
1:
/* Get the new shadow stack pointer. */
rdsspd %eax
/* Use the restore stoken to restore the original shadow stack. */
rstorssp -8(%esi)
/* Save the restore token on the new shadow stack. */
saveprevssp
/* Store the new shadow stack pointer in __ssp[0]. */
movl %eax, oSSP(%edi)
/* Restore the original stack. */
mov %edx, %esp
cfi_startproc
/* Restore ESI from the second scratch register slot. */
movl oSCRATCH2(%edi), %esi
/* Restore EDI from the third scratch register slot. */
movl oSCRATCH3(%edi), %edi
ret
L(skip_ssp):
#endif
/* If the function we call returns we must continue with the /* If the function we call returns we must continue with the
context which is given in the uc_link element. To do this context which is given in the uc_link element. To do this
set the return address for the function the user provides set the return address for the function the user provides
@ -244,7 +122,6 @@ L(call_exit):
call HIDDEN_JUMPTARGET(exit) call HIDDEN_JUMPTARGET(exit)
/* The 'exit' call should never return. In case it does cause /* The 'exit' call should never return. In case it does cause
the process to terminate. */ the process to terminate. */
L(hlt):
hlt hlt
cfi_startproc cfi_startproc
END(__makecontext) END(__makecontext)

101
sysdeps/unix/sysv/linux/i386/setcontext.S
View File

@ -17,7 +17,6 @@
<https://www.gnu.org/licenses/>. */ <https://www.gnu.org/licenses/>. */
#include <sysdep.h> #include <sysdep.h>
#include <asm/prctl.h>
#include "ucontext_i.h" #include "ucontext_i.h"
@ -56,6 +55,9 @@ ENTRY(__setcontext)
movl oFS(%eax), %ecx movl oFS(%eax), %ecx
movw %cx, %fs movw %cx, %fs
/* Fetch the address to return to. */
movl oEIP(%eax), %ecx
/* Load the new stack pointer. */ /* Load the new stack pointer. */
cfi_def_cfa (eax, 0) cfi_def_cfa (eax, 0)
cfi_offset (edi, oEDI) cfi_offset (edi, oEDI)
@ -64,103 +66,6 @@ ENTRY(__setcontext)
cfi_offset (ebx, oEBX) cfi_offset (ebx, oEBX)
movl oESP(%eax), %esp movl oESP(%eax), %esp
#if SHSTK_ENABLED
/* Check if Shadow Stack is enabled. */
testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
jz L(no_shstk)
/* If the base of the target shadow stack is the same as the
base of the current shadow stack, we unwind the shadow
stack. Otherwise it is a stack switch and we look for a
restore token. */
movl oSSP(%eax), %esi
movl %esi, %edi
/* Get the base of the target shadow stack. */
movl (oSSP + 4)(%eax), %ecx
cmpl %gs:SSP_BASE_OFFSET, %ecx
je L(unwind_shadow_stack)
/* Align the saved original shadow stack pointer to the next
8 byte aligned boundary. */
andl $-8, %esi
L(find_restore_token_loop):
/* Look for a restore token. */
movl -8(%esi), %ebx
andl $-8, %ebx
cmpl %esi, %ebx
je L(restore_shadow_stack)
/* Try the next slot. */
subl $8, %esi
jmp L(find_restore_token_loop)
L(restore_shadow_stack):
/* Pop return address from the shadow stack since setcontext
will not return. */
movl $1, %ebx
incsspd %ebx
/* Use the restore stoken to restore the target shadow stack. */
rstorssp -8(%esi)
/* Save the restore token on the old shadow stack. NB: This
restore token may be checked by setcontext or swapcontext
later. */
saveprevssp
/* Record the new shadow stack base that was switched to. */
movl (oSSP + 4)(%eax), %ebx
movl %ebx, %gs:SSP_BASE_OFFSET
L(unwind_shadow_stack):
rdsspd %ebx
subl %edi, %ebx
je L(skip_unwind_shadow_stack)
negl %ebx
shrl $2, %ebx
movl $255, %esi
L(loop):
cmpl %esi, %ebx
cmovb %ebx, %esi
incsspd %esi
subl %esi, %ebx
ja L(loop)
L(skip_unwind_shadow_stack):
/* Load the values of all the preserved registers (except ESP). */
movl oEDI(%eax), %edi
movl oESI(%eax), %esi
movl oEBP(%eax), %ebp
movl oEBX(%eax), %ebx
/* Get the return address set with getcontext. */
movl oEIP(%eax), %ecx
/* Check if return address is valid for the case when setcontext
is invoked from L(exitcode) with linked context. */
rdsspd %eax
cmpl (%eax), %ecx
/* Clear EAX to indicate success. NB: Don't use xorl to keep
EFLAGS for jne. */
movl $0, %eax
jne L(jmp)
/* Return to the new context if return address valid. */
pushl %ecx
ret
L(jmp):
/* Jump to the new context directly. */
jmp *%ecx
L(no_shstk):
#endif
/* Fetch the address to return to. */
movl oEIP(%eax), %ecx
/* Push the return address on the new stack so we can return there. */ /* Push the return address on the new stack so we can return there. */
pushl %ecx pushl %ecx

139
sysdeps/unix/sysv/linux/i386/swapcontext.S
View File

@ -17,7 +17,6 @@
<https://www.gnu.org/licenses/>. */ <https://www.gnu.org/licenses/>. */
#include <sysdep.h> #include <sysdep.h>
#include <asm/prctl.h>
#include "ucontext_i.h" #include "ucontext_i.h"
@ -76,144 +75,6 @@ ENTRY(__swapcontext)
movl oFS(%eax), %edx movl oFS(%eax), %edx
movw %dx, %fs movw %dx, %fs
#if SHSTK_ENABLED
/* Check if Shadow Stack is enabled. */
testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
jz L(no_shstk)
xorl %eax, %eax
cmpl %gs:SSP_BASE_OFFSET, %eax
jnz L(shadow_stack_bound_recorded)
/* Get the base address and size of the default shadow stack
which must be the current shadow stack since nothing has
been recorded yet. */
sub $24, %esp
mov %esp, %ecx
movl $ARCH_CET_STATUS, %ebx
movl $__NR_arch_prctl, %eax
ENTER_KERNEL
testl %eax, %eax
jz L(continue_no_err)
/* This should never happen. */
hlt
L(continue_no_err):
/* Record the base of the current shadow stack. */
movl 8(%esp), %eax
movl %eax, %gs:SSP_BASE_OFFSET
add $24, %esp
L(shadow_stack_bound_recorded):
/* Load address of the context data structure we save in. */
movl 4(%esp), %eax
/* Load address of the context data structure we swap in */
movl 8(%esp), %edx
/* If we unwind the stack, we can't undo stack unwinding. Just
save the target shadow stack pointer as the current shadow
stack pointer. */
movl oSSP(%edx), %ecx
movl %ecx, oSSP(%eax)
/* Save the current shadow stack base in ucontext. */
movl %gs:SSP_BASE_OFFSET, %ecx
movl %ecx, (oSSP + 4)(%eax)
/* If the base of the target shadow stack is the same as the
base of the current shadow stack, we unwind the shadow
stack. Otherwise it is a stack switch and we look for a
restore token. */
movl oSSP(%edx), %esi
movl %esi, %edi
/* Get the base of the target shadow stack. */
movl (oSSP + 4)(%edx), %ecx
cmpl %gs:SSP_BASE_OFFSET, %ecx
je L(unwind_shadow_stack)
/* Align the saved original shadow stack pointer to the next
8 byte aligned boundary. */
andl $-8, %esi
L(find_restore_token_loop):
/* Look for a restore token. */
movl -8(%esi), %ebx
andl $-8, %ebx
cmpl %esi, %ebx
je L(restore_shadow_stack)
/* Try the next slot. */
subl $8, %esi
jmp L(find_restore_token_loop)
L(restore_shadow_stack):
/* The target shadow stack will be restored. Save the current
shadow stack pointer. */
rdsspd %ecx
movl %ecx, oSSP(%eax)
/* Use the restore stoken to restore the target shadow stack. */
rstorssp -8(%esi)
/* Save the restore token on the old shadow stack. NB: This
restore token may be checked by setcontext or swapcontext
later. */
saveprevssp
/* Record the new shadow stack base that was switched to. */
movl (oSSP + 4)(%edx), %ebx
movl %ebx, %gs:SSP_BASE_OFFSET
L(unwind_shadow_stack):
rdsspd %ebx
subl %edi, %ebx
je L(skip_unwind_shadow_stack)
negl %ebx
shrl $2, %ebx
movl $255, %esi
L(loop):
cmpl %esi, %ebx
cmovb %ebx, %esi
incsspd %esi
subl %esi, %ebx
ja L(loop)
L(skip_unwind_shadow_stack):
/* Load the new stack pointer. */
movl oESP(%edx), %esp
/* Load the values of all the preserved registers (except ESP). */
movl oEDI(%edx), %edi
movl oESI(%edx), %esi
movl oEBP(%edx), %ebp
movl oEBX(%edx), %ebx
/* Get the return address set with getcontext. */
movl oEIP(%edx), %ecx
/* Check if return address is valid for the case when setcontext
is invoked from L(exitcode) with linked context. */
rdsspd %eax
cmpl (%eax), %ecx
/* Clear EAX to indicate success. NB: Don't use xorl to keep
EFLAGS for jne. */
movl $0, %eax
jne L(jmp)
/* Return to the new context if return address valid. */
pushl %ecx
ret
L(jmp):
/* Jump to the new context directly. */
jmp *%ecx
L(no_shstk):
#endif
/* Fetch the address to return to. */ /* Fetch the address to return to. */
movl oEIP(%eax), %ecx movl oEIP(%eax), %ecx

5
sysdeps/unix/sysv/linux/i386/sysdep.h
View File

@ -446,9 +446,4 @@ struct libc_do_syscall_args
#endif /* __ASSEMBLER__ */ #endif /* __ASSEMBLER__ */
/* Each shadow stack slot takes 4 bytes. Assuming that each stack
frame takes 128 bytes, this is used to compute shadow stack size
from stack size. */
#define STACK_SIZE_TO_SHADOW_STACK_SIZE_SHIFT 5
#endif /* linux/i386/sysdep.h */ #endif /* linux/i386/sysdep.h */

4
sysdeps/unix/sysv/linux/i386/ucontext_i.sym
View File

@ -22,10 +22,6 @@ oEBP mreg (EBP)
oESP mreg (ESP) oESP mreg (ESP)
oEBX mreg (EBX) oEBX mreg (EBX)
oEIP mreg (EIP) oEIP mreg (EIP)
oSCRATCH1 mreg (EAX)
oSCRATCH2 mreg (ECX)
oSCRATCH3 mreg (EDX)
oFPREGS mcontext (fpregs) oFPREGS mcontext (fpregs)
oSIGMASK ucontext (uc_sigmask) oSIGMASK ucontext (uc_sigmask)
oFPREGSMEM ucontext (__fpregs_mem) oFPREGSMEM ucontext (__fpregs_mem)
oSSP ucontext (__ssp)

24
sysdeps/unix/sysv/linux/i386/vfork.S
View File

@ -20,6 +20,7 @@
#include <bits/errno.h> #include <bits/errno.h>
#include <tcb-offsets.h> #include <tcb-offsets.h>
/* Clone the calling process, but without copying the whole address space. /* Clone the calling process, but without copying the whole address space.
The calling process is suspended until the new process exits or is The calling process is suspended until the new process exits or is
replaced by a call to `execve'. Return -1 for errors, 0 to the new process, replaced by a call to `execve'. Return -1 for errors, 0 to the new process,
@ -46,29 +47,6 @@ ENTRY (__vfork)
/* Branch forward if it failed. */ /* Branch forward if it failed. */
jae SYSCALL_ERROR_LABEL jae SYSCALL_ERROR_LABEL
#if SHSTK_ENABLED
/* Check if shadow stack is in use. */
xorl %edx, %edx
rdsspd %edx
testl %edx, %edx
/* Normal return if shadow stack isn't in use. */
je L(no_shstk)
testl %eax, %eax
/* In parent, normal return. */
jnz L(no_shstk)
/* NB: In child, jump back to caller via indirect branch without
popping shadow stack which is shared with parent. Keep shadow
stack mismatched so that child returns in the vfork-calling
function will trigger SIGSEGV. */
popl %ecx
cfi_adjust_cfa_offset (-4)
jmp *%ecx
L(no_shstk):
#endif
ret ret
PSEUDO_END (__vfork) PSEUDO_END (__vfork)

44
sysdeps/x86/sysdep.h
View File

@ -21,33 +21,6 @@
#include <sysdeps/generic/sysdep.h> #include <sysdeps/generic/sysdep.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 IBT_ENABLED (__CET__ & X86_FEATURE_1_IBT)
# define SHSTK_ENABLED (__CET__ & X86_FEATURE_1_SHSTK)
#else
# define CET_ENABLED 0
# define IBT_ENABLED 0
# define SHSTK_ENABLED 0
#endif
/* Offset for fxsave/xsave area used by _dl_runtime_resolve. Also need /* Offset for fxsave/xsave area used by _dl_runtime_resolve. Also need
space to preserve RCX, RDX, RSI, RDI, R8, R9 and RAX. It must be space to preserve RCX, RDX, RSI, RDI, R8, R9 and RAX. It must be
aligned to 16 bytes for fxsave and 64 bytes for xsave. */ aligned to 16 bytes for fxsave and 64 bytes for xsave. */
@ -66,27 +39,10 @@ enum cf_protection_level
/* Syntactic details of assembler. */ /* Syntactic details of assembler. */
#ifdef _CET_ENDBR
# define _CET_NOTRACK notrack
#else
# define _CET_ENDBR
# define _CET_NOTRACK
#endif
/* ELF uses byte-counts for .align, most others use log2 of count of bytes. */ /* ELF uses byte-counts for .align, most others use log2 of count of bytes. */
#define ALIGNARG(log2) 1<<log2 #define ALIGNARG(log2) 1<<log2
#define ASM_SIZE_DIRECTIVE(name) .size name,.-name; #define ASM_SIZE_DIRECTIVE(name) .size name,.-name;
/* 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
/* Common entry 16 byte aligns. */ /* Common entry 16 byte aligns. */
#define ENTRY(name) ENTRY_P2ALIGN (name, 4) #define ENTRY(name) ENTRY_P2ALIGN (name, 4)

42
sysdeps/x86_64/sysdep.h
View File

@ -22,10 +22,52 @@
#include <sysdeps/x86/sysdep.h> #include <sysdeps/x86/sysdep.h>
#include <x86-lp_size.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__ #ifdef __ASSEMBLER__
/* Syntactic details of 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 /* 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. 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 Expression is DW_OP_drop, DW_OP_breg7 (%rsp is register 7), sleb128 offset