[patch 10/24] x86/entry: Convert INT3 exception to IDTENTRY

Thomas Gleixner
2020-02-25T23:29:12Z

Convert #BP to IDTENTRY:
- 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 | 7 -------
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 | 11 +++++------
arch/x86/xen/enlighten_pv.c | 2 +-
arch/x86/xen/xen-asm_64.S | 2 +-
8 files changed, 9 insertions(+), 20 deletions(-)

--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1698,13 +1698,6 @@ SYM_CODE_START(nmi)
#endif
SYM_CODE_END(nmi)

-SYM_CODE_START(int3)
- ASM_CLAC
- pushl $0
- pushl $do_int3
- jmp common_exception
-SYM_CODE_END(int3)
-
SYM_CODE_START(general_protection)
ASM_CLAC
pushl $do_general_protection
--- 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_BP int3 do_int3 has_error_code=0
idtentry X86_TRAP_BR bounds do_bounds has_error_code=0
idtentry X86_TRAP_UD invalid_op do_invalid_op has_error_code=0
idtentry X86_TRAP_NM device_not_available do_device_not_available has_error_code=0
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -78,6 +78,7 @@ static __always_inline void __##func(str

/* Simple exception entries: */
DECLARE_IDTENTRY(X86_TRAP_DE, exc_divide_error);
+DECLARE_IDTENTRY(X86_TRAP_BP, exc_int3);
DECLARE_IDTENTRY(X86_TRAP_OF, exc_overflow);

#endif
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -13,7 +13,6 @@

asmlinkage void debug(void);
asmlinkage void nmi(void);
-asmlinkage void int3(void);
asmlinkage void bounds(void);
asmlinkage void invalid_op(void);
asmlinkage void device_not_available(void);
@@ -38,7 +37,6 @@ asmlinkage void simd_coprocessor_error(v
#if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
asmlinkage void xen_xennmi(void);
asmlinkage void xen_xendebug(void);
-asmlinkage void xen_int3(void);
asmlinkage void xen_bounds(void);
asmlinkage void xen_invalid_op(void);
asmlinkage void xen_device_not_available(void);
@@ -60,7 +58,6 @@ asmlinkage void xen_simd_coprocessor_err

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_bounds(struct pt_regs *regs, long error_code);
dotraplinkage void do_invalid_op(struct pt_regs *regs, long error_code);
dotraplinkage void do_device_not_available(struct pt_regs *regs, long error_code);
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -57,7 +57,7 @@ struct idt_data {
*/
static const __initconst struct idt_data early_idts[] = {
INTG(X86_TRAP_DB, debug),
- SYSG(X86_TRAP_BP, int3),
+ SYSG(X86_TRAP_BP, asm_exc_int3),
#ifdef CONFIG_X86_32
INTG(X86_TRAP_PF, page_fault),
#endif
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -580,7 +580,7 @@ dotraplinkage void do_general_protection
}
NOKPROBE_SYMBOL(do_general_protection);

-dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code)
+DEFINE_IDTENTRY(exc_int3)
{
if (poke_int3_handler(regs))
return;
@@ -601,8 +601,8 @@ dotraplinkage void notrace do_int3(struc
RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");

#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
- if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
- SIGTRAP) == NOTIFY_STOP)
+ if (kgdb_ll_trap(DIE_INT3, "int3", regs, 0, X86_TRAP_BP,
+ SIGTRAP) == NOTIFY_STOP)
goto exit;
#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */

@@ -611,12 +611,12 @@ dotraplinkage void notrace do_int3(struc
goto exit;
#endif

- if (notify_die(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
+ if (notify_die(DIE_INT3, "int3", regs, 0, X86_TRAP_BP,
SIGTRAP) == NOTIFY_STOP)
goto exit;

cond_local_irq_enable(regs);
- do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, 0, NULL);
+ do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, 0, 0, NULL);
cond_local_irq_disable(regs);

exit:
@@ -625,7 +625,6 @@ dotraplinkage void notrace do_int3(struc
rcu_nmi_exit();
}
}
-NOKPROBE_SYMBOL(do_int3);

#ifdef CONFIG_X86_64
/*
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -614,7 +614,7 @@ static struct trap_array_entry trap_arra
{ machine_check, xen_machine_check, true },
#endif
{ nmi, xen_xennmi, true },
- { int3, xen_int3, false },
+ TRAP_ENTRY(exc_int3, false ),
TRAP_ENTRY(exc_overflow, false ),
#ifdef CONFIG_IA32_EMULATION
{ entry_INT80_compat, xen_entry_INT80_compat, false },
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -31,7 +31,7 @@ SYM_CODE_END(xen_\name)
xen_pv_trap asm_exc_divide_error
xen_pv_trap debug
xen_pv_trap xendebug
-xen_pv_trap int3
+xen_pv_trap asm_exc_int3
xen_pv_trap xennmi
xen_pv_trap asm_exc_overflow
xen_pv_trap bounds