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-rw-r--r--arch/x86/entry/entry.S21
-rw-r--r--arch/x86/entry/entry_32.S6
-rw-r--r--arch/x86/entry/syscalls/syscall_32.tbl4
-rw-r--r--arch/x86/entry/syscalls/syscall_64.tbl4
4 files changed, 33 insertions, 2 deletions
diff --git a/arch/x86/entry/entry.S b/arch/x86/entry/entry.S
index d9feadffa972..b7ea3e8e9ecc 100644
--- a/arch/x86/entry/entry.S
+++ b/arch/x86/entry/entry.S
@@ -9,6 +9,8 @@
#include <asm/unwind_hints.h>
#include <asm/segment.h>
#include <asm/cache.h>
+#include <asm/cpufeatures.h>
+#include <asm/nospec-branch.h>
#include "calling.h"
@@ -19,6 +21,9 @@ SYM_FUNC_START(entry_ibpb)
movl $PRED_CMD_IBPB, %eax
xorl %edx, %edx
wrmsr
+
+ /* Make sure IBPB clears return stack preductions too. */
+ FILL_RETURN_BUFFER %rax, RSB_CLEAR_LOOPS, X86_BUG_IBPB_NO_RET
RET
SYM_FUNC_END(entry_ibpb)
/* For KVM */
@@ -46,3 +51,19 @@ EXPORT_SYMBOL_GPL(mds_verw_sel);
.popsection
THUNK warn_thunk_thunk, __warn_thunk
+
+#ifndef CONFIG_X86_64
+/*
+ * Clang's implementation of TLS stack cookies requires the variable in
+ * question to be a TLS variable. If the variable happens to be defined as an
+ * ordinary variable with external linkage in the same compilation unit (which
+ * amounts to the whole of vmlinux with LTO enabled), Clang will drop the
+ * segment register prefix from the references, resulting in broken code. Work
+ * around this by avoiding the symbol used in -mstack-protector-guard-symbol=
+ * entirely in the C code, and use an alias emitted by the linker script
+ * instead.
+ */
+#ifdef CONFIG_STACKPROTECTOR
+EXPORT_SYMBOL(__ref_stack_chk_guard);
+#endif
+#endif
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index d3a814efbff6..20be5758c2d2 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -871,6 +871,8 @@ SYM_FUNC_START(entry_SYSENTER_32)
/* Now ready to switch the cr3 */
SWITCH_TO_USER_CR3 scratch_reg=%eax
+ /* Clobbers ZF */
+ CLEAR_CPU_BUFFERS
/*
* Restore all flags except IF. (We restore IF separately because
@@ -881,7 +883,6 @@ SYM_FUNC_START(entry_SYSENTER_32)
BUG_IF_WRONG_CR3 no_user_check=1
popfl
popl %eax
- CLEAR_CPU_BUFFERS
/*
* Return back to the vDSO, which will pop ecx and edx.
@@ -1144,7 +1145,6 @@ SYM_CODE_START(asm_exc_nmi)
/* Not on SYSENTER stack. */
call exc_nmi
- CLEAR_CPU_BUFFERS
jmp .Lnmi_return
.Lnmi_from_sysenter_stack:
@@ -1165,6 +1165,7 @@ SYM_CODE_START(asm_exc_nmi)
CHECK_AND_APPLY_ESPFIX
RESTORE_ALL_NMI cr3_reg=%edi pop=4
+ CLEAR_CPU_BUFFERS
jmp .Lirq_return
#ifdef CONFIG_X86_ESPFIX32
@@ -1206,6 +1207,7 @@ SYM_CODE_START(asm_exc_nmi)
* 1 - orig_ax
*/
lss (1+5+6)*4(%esp), %esp # back to espfix stack
+ CLEAR_CPU_BUFFERS
jmp .Lirq_return
#endif
SYM_CODE_END(asm_exc_nmi)
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 534c74b14fab..4d0fb2fba7e2 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -468,3 +468,7 @@
460 i386 lsm_set_self_attr sys_lsm_set_self_attr
461 i386 lsm_list_modules sys_lsm_list_modules
462 i386 mseal sys_mseal
+463 i386 setxattrat sys_setxattrat
+464 i386 getxattrat sys_getxattrat
+465 i386 listxattrat sys_listxattrat
+466 i386 removexattrat sys_removexattrat
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 7093ee21c0d1..5eb708bff1c7 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -386,6 +386,10 @@
460 common lsm_set_self_attr sys_lsm_set_self_attr
461 common lsm_list_modules sys_lsm_list_modules
462 common mseal sys_mseal
+463 common setxattrat sys_setxattrat
+464 common getxattrat sys_getxattrat
+465 common listxattrat sys_listxattrat
+466 common removexattrat sys_removexattrat
#
# Due to a historical design error, certain syscalls are numbered differently