[tip: x86/entry] x86/entry: Convert Segment not present exception to IDTENTRY

From: tip-bot2 for Thomas Gleixner
Date: Tue May 19 2020 - 16:01:32 EST


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

Commit-ID: 403ad51200262306a08c9fa0b3120f51cce95445
Gitweb: https://git.kernel.org/tip/403ad51200262306a08c9fa0b3120f51cce95445
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Tue, 25 Feb 2020 23:16:23 +01:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Tue, 19 May 2020 16:04:01 +02:00

x86/entry: Convert Segment not present exception to IDTENTRY

Convert #NP 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@xxxxxxxxxxxxx>
Reviewed-by: Alexandre Chartre <alexandre.chartre@xxxxxxxxxx>
Acked-by: Andy Lutomirski <luto@xxxxxxxxxx>
Acked-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20200505134905.443591450@xxxxxxxxxxxxx



---
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(-)

diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 2143a62..b01dbb3 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(segment_not_present)
- ASM_CLAC
- pushl $do_segment_not_present
- jmp common_exception
-SYM_CODE_END(segment_not_present)
-
SYM_CODE_START(stack_segment)
ASM_CLAC
pushl $do_stack_segment
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 07307cf..367a207 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_NP segment_not_present do_segment_not_present has_error_code=1
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
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index aa0d465..d517c09 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -132,5 +132,6 @@ 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);

#endif
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index 30bc589..970c888 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 segment_not_present(void);
asmlinkage void stack_segment(void);
asmlinkage void general_protection(void);
asmlinkage void page_fault(void);
@@ -35,7 +34,6 @@ asmlinkage void xen_xennmi(void);
asmlinkage void xen_xendebug(void);
asmlinkage void xen_int3(void);
asmlinkage void xen_double_fault(void);
-asmlinkage void xen_segment_not_present(void);
asmlinkage void xen_stack_segment(void);
asmlinkage void xen_general_protection(void);
asmlinkage void xen_page_fault(void);
@@ -52,7 +50,6 @@ 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_segment_not_present(struct pt_regs *regs, long error_code);
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);
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index caa740d..b9acc7f 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -80,7 +80,7 @@ static const __initconst struct idt_data def_idts[] = {
INTG(X86_TRAP_NM, asm_exc_device_not_available),
INTG(X86_TRAP_OLD_MF, asm_exc_coproc_segment_overrun),
INTG(X86_TRAP_TS, asm_exc_invalid_tss),
- INTG(X86_TRAP_NP, segment_not_present),
+ INTG(X86_TRAP_NP, asm_exc_segment_not_present),
INTG(X86_TRAP_SS, stack_segment),
INTG(X86_TRAP_GP, general_protection),
INTG(X86_TRAP_SPURIOUS, spurious_interrupt_bug),
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 10ab083..88ba5f0 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -258,6 +258,12 @@ DEFINE_IDTENTRY_ERRORCODE(exc_invalid_tss)
0, NULL);
}

+DEFINE_IDTENTRY_ERRORCODE(exc_segment_not_present)
+{
+ do_error_trap(regs, error_code, "segment not present", X86_TRAP_NP,
+ 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) \
@@ -265,7 +271,6 @@ dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \
do_error_trap(regs, error_code, str, trapnr, signr, sicode, addr); \
}

-DO_ERROR(X86_TRAP_NP, SIGBUS, 0, NULL, "segment not present", segment_not_present)
DO_ERROR(X86_TRAP_SS, SIGBUS, 0, NULL, "stack segment", stack_segment)
#undef IP

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 2ed7d2f..5437e28 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -629,7 +629,7 @@ static struct trap_array_entry trap_array[] = {
TRAP_ENTRY(exc_device_not_available, false ),
TRAP_ENTRY(exc_coproc_segment_overrun, false ),
TRAP_ENTRY(exc_invalid_tss, false ),
- { segment_not_present, xen_segment_not_present, false },
+ TRAP_ENTRY(exc_segment_not_present, false ),
{ stack_segment, xen_stack_segment, false },
{ general_protection, xen_general_protection, false },
{ spurious_interrupt_bug, xen_spurious_interrupt_bug, false },
diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
index f7a890c..c8ce7ad 100644
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -40,7 +40,7 @@ xen_pv_trap asm_exc_device_not_available
xen_pv_trap double_fault
xen_pv_trap asm_exc_coproc_segment_overrun
xen_pv_trap asm_exc_invalid_tss
-xen_pv_trap segment_not_present
+xen_pv_trap asm_exc_segment_not_present
xen_pv_trap stack_segment
xen_pv_trap general_protection
xen_pv_trap page_fault