-#define SAVE_ALL \
- cld; \
- pushl %fs; \
- CFI_ADJUST_CFA_OFFSET 4;\
- /*CFI_REL_OFFSET fs, 0;*/\
- pushl %es; \
- CFI_ADJUST_CFA_OFFSET 4;\
- /*CFI_REL_OFFSET es, 0;*/\
- pushl %ds; \
- CFI_ADJUST_CFA_OFFSET 4;\
- /*CFI_REL_OFFSET ds, 0;*/\
- pushl %eax; \
- CFI_ADJUST_CFA_OFFSET 4;\
- CFI_REL_OFFSET eax, 0;\
- pushl %ebp; \
- CFI_ADJUST_CFA_OFFSET 4;\
- CFI_REL_OFFSET ebp, 0;\
- pushl %edi; \
- CFI_ADJUST_CFA_OFFSET 4;\
- CFI_REL_OFFSET edi, 0;\
- pushl %esi; \
- CFI_ADJUST_CFA_OFFSET 4;\
- CFI_REL_OFFSET esi, 0;\
- pushl %edx; \
- CFI_ADJUST_CFA_OFFSET 4;\
- CFI_REL_OFFSET edx, 0;\
- pushl %ecx; \
- CFI_ADJUST_CFA_OFFSET 4;\
- CFI_REL_OFFSET ecx, 0;\
- pushl %ebx; \
- CFI_ADJUST_CFA_OFFSET 4;\
- CFI_REL_OFFSET ebx, 0;\
- movl $(__USER_DS), %edx; \
- movl %edx, %ds; \
- movl %edx, %es; \
- movl $(__KERNEL_PERCPU), %edx; \
+/*
+ * User gs save/restore
+ *
+ * %gs is used for userland TLS and kernel only uses it for stack
+ * canary which is required to be at %gs:20 by gcc. Read the comment
+ * at the top of stackprotector.h for more info.
+ *
+ * Local labels 98 and 99 are used.
+ */
+#ifdef CONFIG_X86_32_LAZY_GS
+
+ /* unfortunately push/pop can't be no-op */
+.macro PUSH_GS
+ pushl $0
+ CFI_ADJUST_CFA_OFFSET 4
+.endm
+.macro POP_GS pop=0
+ addl $(4 + \pop), %esp
+ CFI_ADJUST_CFA_OFFSET -(4 + \pop)
+.endm
+.macro POP_GS_EX
+.endm
+
+ /* all the rest are no-op */
+.macro PTGS_TO_GS
+.endm
+.macro PTGS_TO_GS_EX
+.endm
+.macro GS_TO_REG reg
+.endm
+.macro REG_TO_PTGS reg
+.endm
+.macro SET_KERNEL_GS reg
+.endm
+
+#else /* CONFIG_X86_32_LAZY_GS */
+
+.macro PUSH_GS
+ pushl %gs
+ CFI_ADJUST_CFA_OFFSET 4
+ /*CFI_REL_OFFSET gs, 0*/
+.endm
+
+.macro POP_GS pop=0
+98: popl %gs
+ CFI_ADJUST_CFA_OFFSET -4
+ /*CFI_RESTORE gs*/
+ .if \pop <> 0
+ add $\pop, %esp
+ CFI_ADJUST_CFA_OFFSET -\pop
+ .endif
+.endm
+.macro POP_GS_EX
+.pushsection .fixup, "ax"
+99: movl $0, (%esp)
+ jmp 98b
+.section __ex_table, "a"
+ .align 4
+ .long 98b, 99b
+.popsection
+.endm
+
+.macro PTGS_TO_GS
+98: mov PT_GS(%esp), %gs
+.endm
+.macro PTGS_TO_GS_EX
+.pushsection .fixup, "ax"
+99: movl $0, PT_GS(%esp)
+ jmp 98b
+.section __ex_table, "a"
+ .align 4
+ .long 98b, 99b
+.popsection
+.endm
+
+.macro GS_TO_REG reg
+ movl %gs, \reg
+ /*CFI_REGISTER gs, \reg*/
+.endm
+.macro REG_TO_PTGS reg
+ movl \reg, PT_GS(%esp)
+ /*CFI_REL_OFFSET gs, PT_GS*/
+.endm
+.macro SET_KERNEL_GS reg
+ movl $(__KERNEL_STACK_CANARY), \reg
+ movl \reg, %gs
+.endm
+
+#endif /* CONFIG_X86_32_LAZY_GS */
+
+.macro SAVE_ALL
+ cld
+ PUSH_GS
+ pushl %fs
+ CFI_ADJUST_CFA_OFFSET 4
+ /*CFI_REL_OFFSET fs, 0;*/
+ pushl %es
+ CFI_ADJUST_CFA_OFFSET 4
+ /*CFI_REL_OFFSET es, 0;*/
+ pushl %ds
+ CFI_ADJUST_CFA_OFFSET 4
+ /*CFI_REL_OFFSET ds, 0;*/
+ pushl %eax
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET eax, 0
+ pushl %ebp
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET ebp, 0
+ pushl %edi
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET edi, 0
+ pushl %esi
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET esi, 0
+ pushl %edx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET edx, 0
+ pushl %ecx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET ecx, 0
+ pushl %ebx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET ebx, 0
+ movl $(__USER_DS), %edx
+ movl %edx, %ds
+ movl %edx, %es
+ movl $(__KERNEL_PERCPU), %edx