[patch 05/16] x86/entry: Convert Debug exception to IDTENTRY_DB
From: Thomas Gleixner
Date: Tue Feb 25 2020 - 18:26:50 EST
Convert #DB to IDTENTRY_ERRORCODE:
- Implement the C entry point with DEFINE_IDTENTRY_DB
- 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@xxxxxxxxxxxxx>
---
arch/x86/entry/entry_32.S | 10 ----------
arch/x86/entry/entry_64.S | 2 --
arch/x86/include/asm/idtentry.h | 4 ++++
arch/x86/include/asm/traps.h | 3 ---
arch/x86/kernel/idt.c | 8 ++++----
arch/x86/kernel/traps.c | 13 ++++++-------
arch/x86/xen/enlighten_pv.c | 2 +-
arch/x86/xen/xen-asm_64.S | 4 ++--
8 files changed, 17 insertions(+), 29 deletions(-)
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1455,16 +1455,6 @@ SYM_CODE_START_LOCAL_NOALIGN(common_exce
jmp ret_from_exception
SYM_CODE_END(common_exception)
-SYM_CODE_START(debug)
- /*
- * Entry from sysenter is now handled in common_exception
- */
- ASM_CLAC
- pushl $0
- pushl $do_debug
- jmp common_exception
-SYM_CODE_END(debug)
-
#ifdef CONFIG_DOUBLEFAULT
SYM_CODE_START(double_fault)
1:
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1066,12 +1066,10 @@ idtentry X86_TRAP_PF page_fault do_pag
idtentry X86_TRAP_PF async_page_fault do_async_page_fault has_error_code=1
#endif
-idtentry_mce_db X86_TRAP_DB debug do_debug
idtentry_df X86_TRAP_DF double_fault do_double_fault
#ifdef CONFIG_XEN_PV
idtentry 512 /* dummy */ hypervisor_callback xen_do_hypervisor_callback has_error_code=0
-idtentry X86_TRAP_DB xendebug do_debug has_error_code=0
#endif
/*
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -242,4 +242,8 @@ DECLARE_IDTENTRY_MCE(X86_TRAP_MC, exc_ma
DECLARE_IDTENTRY_NMI(X86_TRAP_NMI, exc_nmi);
DECLARE_IDTENTRY_XEN(X86_TRAP_NMI, nmi);
+/* #DB */
+DECLARE_IDTENTRY_DEBUG(X86_TRAP_DB, exc_debug);
+DECLARE_IDTENTRY_XEN(X86_TRAP_DB, debug);
+
#endif
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -11,7 +11,6 @@
#define dotraplinkage __visible
-asmlinkage void debug(void);
#ifdef CONFIG_X86_64
asmlinkage void double_fault(void);
#endif
@@ -19,12 +18,10 @@ asmlinkage void page_fault(void);
asmlinkage void async_page_fault(void);
#if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
-asmlinkage void xen_xendebug(void);
asmlinkage void xen_double_fault(void);
asmlinkage void xen_page_fault(void);
#endif
-dotraplinkage void do_debug(struct pt_regs *regs, long error_code);
#if defined(CONFIG_X86_64) || defined(CONFIG_DOUBLEFAULT)
dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsigned long cr2);
#endif
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -56,7 +56,7 @@ struct idt_data {
* stacks work only after cpu_init().
*/
static const __initconst struct idt_data early_idts[] = {
- INTG(X86_TRAP_DB, debug),
+ INTG(X86_TRAP_DB, asm_exc_debug),
SYSG(X86_TRAP_BP, asm_exc_int3),
#ifdef CONFIG_X86_32
INTG(X86_TRAP_PF, page_fault),
@@ -90,7 +90,7 @@ static const __initconst struct idt_data
#else
INTG(X86_TRAP_DF, double_fault),
#endif
- INTG(X86_TRAP_DB, debug),
+ INTG(X86_TRAP_DB, asm_exc_debug),
#ifdef CONFIG_X86_MCE
INTG(X86_TRAP_MC, asm_exc_machine_check),
@@ -161,7 +161,7 @@ static const __initconst struct idt_data
* stack set to DEFAULT_STACK (0). Required for NMI trap handling.
*/
static const __initconst struct idt_data dbg_idts[] = {
- INTG(X86_TRAP_DB, debug),
+ INTG(X86_TRAP_DB, asm_exc_debug),
};
#endif
@@ -182,7 +182,7 @@ gate_desc debug_idt_table[IDT_ENTRIES] _
* cpu_init() when the TSS has been initialized.
*/
static const __initconst struct idt_data ist_idts[] = {
- ISTG(X86_TRAP_DB, debug, IST_INDEX_DB),
+ ISTG(X86_TRAP_DB, asm_exc_debug, IST_INDEX_DB),
ISTG(X86_TRAP_NMI, asm_exc_nmi, IST_INDEX_NMI),
ISTG(X86_TRAP_DF, double_fault, IST_INDEX_DF),
#ifdef CONFIG_X86_MCE
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -739,7 +739,7 @@ static bool is_sysenter_singlestep(struc
*
* May run on IST stack.
*/
-dotraplinkage void do_debug(struct pt_regs *regs, long error_code)
+DEFINE_IDTENTRY_DEBUG(exc_debug)
{
struct task_struct *tsk = current;
int user_icebp = 0;
@@ -800,8 +800,8 @@ dotraplinkage void do_debug(struct pt_re
goto exit;
#endif
- if (notify_die(DIE_DEBUG, "debug", regs, (long)&dr6, error_code,
- SIGTRAP) == NOTIFY_STOP)
+ if (notify_die(DIE_DEBUG, "debug", regs, (long)&dr6, 0,
+ SIGTRAP) == NOTIFY_STOP)
goto exit;
/*
@@ -814,8 +814,8 @@ dotraplinkage void do_debug(struct pt_re
cond_local_irq_enable(regs);
if (v8086_mode(regs)) {
- handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code,
- X86_TRAP_DB);
+ handle_vm86_trap((struct kernel_vm86_regs *) regs, 0,
+ X86_TRAP_DB);
cond_local_irq_disable(regs);
debug_stack_usage_dec();
goto exit;
@@ -834,14 +834,13 @@ dotraplinkage void do_debug(struct pt_re
}
si_code = get_si_code(tsk->thread.debugreg6);
if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp)
- send_sigtrap(regs, error_code, si_code);
+ send_sigtrap(regs, 0, si_code);
cond_local_irq_disable(regs);
debug_stack_usage_dec();
exit:
ist_exit(regs);
}
-NOKPROBE_SYMBOL(do_debug);
/*
* Note that we play around with the 'TS' bit in an attempt to get
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -613,7 +613,7 @@ struct trap_array_entry {
.ist_okay = ist_ok }
static struct trap_array_entry trap_array[] = {
- { debug, xen_xendebug, true },
+ TRAP_ENTRY_REDIR(exc_debug, exc_xendebug, true ),
{ double_fault, xen_double_fault, true },
#ifdef CONFIG_X86_MCE
TRAP_ENTRY(exc_machine_check, true ),
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -29,8 +29,8 @@ SYM_CODE_END(xen_\name)
.endm
xen_pv_trap asm_exc_divide_error
-xen_pv_trap debug
-xen_pv_trap xendebug
+xen_pv_trap asm_exc_debug
+xen_pv_trap asm_exc_xendebug
xen_pv_trap asm_exc_int3
xen_pv_trap asm_exc_xennmi
xen_pv_trap asm_exc_overflow