[patch 18/24] x86/entry: Convert Stack segment exception to IDTENTRY

Thomas Gleixner
2020-02-25T23:29:09Z

Convert #SS to IDTENTRY_ERRORCODE:
- Implement the C entry point with DEFINE_IDTENTRY
- Emit the ASM stub with DECLARE_IDTENTRY
- Remove the ASM idtentry in 64bit
- Remove the open coded ASM entry code in 32bit
- Fixup the XEN/PV code
- Remove the old prototyoes

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/entry/entry_32.S | 6 ------
arch/x86/entry/entry_64.S | 1 -
arch/x86/include/asm/idtentry.h | 1 +
arch/x86/include/asm/traps.h | 3 ---
arch/x86/kernel/idt.c | 2 +-
arch/x86/kernel/traps.c | 7 ++++++-
arch/x86/xen/enlighten_pv.c | 2 +-
arch/x86/xen/xen-asm_64.S | 2 +-
8 files changed, 10 insertions(+), 14 deletions(-)

--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1327,12 +1327,6 @@ SYM_CODE_START(native_iret)
SYM_CODE_END(native_iret)
#endif

-SYM_CODE_START(stack_segment)
- ASM_CLAC
- pushl $do_stack_segment
- jmp common_exception
-SYM_CODE_END(stack_segment)
-
SYM_CODE_START(alignment_check)
ASM_CLAC
pushl $do_alignment_check
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1061,7 +1061,6 @@ apicinterrupt IRQ_WORK_VECTOR irq_work
* Exception entry points.
*/

-idtentry X86_TRAP_SS stack_segment do_stack_segment has_error_code=1
idtentry X86_TRAP_GP general_protection do_general_protection has_error_code=1
idtentry X86_TRAP_SPURIOUS spurious_interrupt_bug do_spurious_interrupt_bug has_error_code=0
idtentry X86_TRAP_MF coprocessor_error do_coprocessor_error has_error_code=0
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -131,5 +131,6 @@ DECLARE_IDTENTRY(X86_TRAP_OLD_MF, exc_co
/* Simple exception entries with error code pushed by hardware */
DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_TS, exc_invalid_tss);
DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_NP, exc_segment_not_present);
+DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_SS, exc_stack_segment);

#endif
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -16,7 +16,6 @@ asmlinkage void nmi(void);
#ifdef CONFIG_X86_64
asmlinkage void double_fault(void);
#endif
-asmlinkage void stack_segment(void);
asmlinkage void general_protection(void);
asmlinkage void page_fault(void);
asmlinkage void async_page_fault(void);
@@ -32,7 +31,6 @@ asmlinkage void simd_coprocessor_error(v
asmlinkage void xen_xennmi(void);
asmlinkage void xen_xendebug(void);
asmlinkage void xen_double_fault(void);
-asmlinkage void xen_stack_segment(void);
asmlinkage void xen_general_protection(void);
asmlinkage void xen_page_fault(void);
asmlinkage void xen_spurious_interrupt_bug(void);
@@ -49,7 +47,6 @@ dotraplinkage void do_nmi(struct pt_regs
#if defined(CONFIG_X86_64) || defined(CONFIG_DOUBLEFAULT)
dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsigned long cr2);
#endif
-dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code);
dotraplinkage void do_general_protection(struct pt_regs *regs, long error_code);
dotraplinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code, unsigned long address);
dotraplinkage void do_spurious_interrupt_bug(struct pt_regs *regs, long error_code);
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -78,7 +78,7 @@ static const __initconst struct idt_data
INTG(X86_TRAP_OLD_MF, asm_exc_coproc_segment_overrun),
INTG(X86_TRAP_TS, asm_exc_invalid_tss),
INTG(X86_TRAP_NP, asm_exc_segment_not_present),
- INTG(X86_TRAP_SS, stack_segment),
+ INTG(X86_TRAP_SS, asm_exc_stack_segment),
INTG(X86_TRAP_GP, general_protection),
INTG(X86_TRAP_SPURIOUS, spurious_interrupt_bug),
INTG(X86_TRAP_MF, coprocessor_error),
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -314,6 +314,12 @@ DEFINE_IDTENTRY_ERRORCODE(exc_segment_no
SIGBUS, 0, NULL);
}

+DEFINE_IDTENTRY_ERRORCODE(exc_stack_segment)
+{
+ do_error_trap(regs, error_code, "stack segment", X86_TRAP_SS, SIGBUS,
+ 0, NULL);
+}
+
#define IP ((void __user *)uprobe_get_trap_addr(regs))
#define DO_ERROR(trapnr, signr, sicode, addr, str, name) \
dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \
@@ -321,7 +327,6 @@ dotraplinkage void do_##name(struct pt_r
do_error_trap(regs, error_code, str, trapnr, signr, sicode, addr); \
}

-DO_ERROR(X86_TRAP_SS, SIGBUS, 0, NULL, "stack segment", stack_segment)
DO_ERROR(X86_TRAP_AC, SIGBUS, BUS_ADRALN, NULL, "alignment check", alignment_check)
#undef IP

--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -627,7 +627,7 @@ static struct trap_array_entry trap_arra
TRAP_ENTRY(exc_coproc_segment_overrun, false ),
TRAP_ENTRY(exc_invalid_tss, false ),
TRAP_ENTRY(exc_segment_not_present, false ),
- { stack_segment, xen_stack_segment, false },
+ TRAP_ENTRY(exc_stack_segment, false ),
{ general_protection, xen_general_protection, false },
{ spurious_interrupt_bug, xen_spurious_interrupt_bug, false },
{ coprocessor_error, xen_coprocessor_error, false },
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -41,7 +41,7 @@ xen_pv_trap double_fault
xen_pv_trap asm_exc_coproc_segment_overrun
xen_pv_trap asm_exc_invalid_tss
xen_pv_trap asm_exc_segment_not_present
-xen_pv_trap stack_segment
+xen_pv_trap asm_exc_stack_segment
xen_pv_trap general_protection
xen_pv_trap page_fault
xen_pv_trap spurious_interrupt_bug