[tip: x86/entry] x86/entry: Convert Stack segment exception to IDTENTRY

tip-bot2 for Thomas Gleixner
2020-05-19T20:01:51Z

The following commit has been merged into the x86/entry branch of tip:

Commit-ID: 24e4d217ea653837567c4763fa465d28d1422e63
Gitweb: https://git.kernel.org/tip/24e4d217ea653837567c4763fa465d28d1422e63
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 25 Feb 2020 23:16:24 +01:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Tue, 19 May 2020 16:04:01 +02:00

x86/entry: Convert Stack segment exception to IDTENTRY

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 prototypes

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200505134905.539867572@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 | 12 ++++--------
arch/x86/xen/enlighten_pv.c | 2 +-
arch/x86/xen/xen-asm_64.S | 2 +-
8 files changed, 8 insertions(+), 21 deletions(-)

diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index b01dbb3..ffe43d2 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1318,12 +1318,6 @@ 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
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 367a207..c92592d 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1073,7 +1073,6 @@ apicinterrupt IRQ_WORK_VECTOR irq_work_interrupt smp_irq_work_interrupt
*/

idtentry X86_TRAP_BP int3 do_int3 has_error_code=0
-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
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index d517c09..4c0abd3 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -133,5 +133,6 @@ DECLARE_IDTENTRY(X86_TRAP_OLD_MF, exc_coproc_segment_overrun);
/* 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
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index 970c888..5e580ff 100644
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -17,7 +17,6 @@ asmlinkage void int3(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);
@@ -34,7 +33,6 @@ asmlinkage void xen_xennmi(void);
asmlinkage void xen_xendebug(void);
asmlinkage void xen_int3(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);
@@ -50,7 +48,6 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code);
dotraplinkage void do_nmi(struct pt_regs *regs, long error_code);
dotraplinkage void do_int3(struct pt_regs *regs, long error_code);
dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsigned long cr2);
-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);
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index b9acc7f..8d95cbf 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -81,7 +81,7 @@ static const __initconst struct idt_data def_idts[] = {
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),
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 88ba5f0..3dfdc4d 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -264,16 +264,12 @@ DEFINE_IDTENTRY_ERRORCODE(exc_segment_not_present)
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) \
-{ \
- do_error_trap(regs, error_code, str, trapnr, signr, sicode, addr); \
+DEFINE_IDTENTRY_ERRORCODE(exc_stack_segment)
+{
+ do_error_trap(regs, error_code, "stack segment", X86_TRAP_SS, SIGBUS,
+ 0, NULL);
}

-DO_ERROR(X86_TRAP_SS, SIGBUS, 0, NULL, "stack segment", stack_segment)
-#undef IP
-
dotraplinkage void do_alignment_check(struct pt_regs *regs, long error_code)
{
char *str = "alignment check";
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 5437e28..333222a 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -630,7 +630,7 @@ static struct trap_array_entry trap_array[] = {
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 },
diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
index c8ce7ad..0ecc055 100644
--- 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