[tip: x86/entry] x86/entry: Convert Machine Check to IDTENTRY_IST

From: tip-bot2 for Thomas Gleixner
Date: Tue May 19 2020 - 16:01:41 EST

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

Commit-ID: aaa4947defff8e6e647e5c1dbc0b4b0dfd4c4359
Gitweb: https://git.kernel.org/tip/aaa4947defff8e6e647e5c1dbc0b4b0dfd4c4359
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Tue, 25 Feb 2020 23:33:23 +01:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Tue, 19 May 2020 16:04:08 +02:00

x86/entry: Convert Machine Check to IDTENTRY_IST

Convert #MC to IDTENTRY_MCE:
- Implement the C entry points with DEFINE_IDTENTRY_MCE
- Emit the ASM stub with DECLARE_IDTENTRY_MCE
- Remove the ASM idtentry in 64bit
- Remove the open coded ASM entry code in 32bit
- Fixup the XEN/PV code
- Remove the old prototypes
- Remove the error code from *machine_check_vector() as
it is always 0 and not used by any of the functions
it can point to. Fixup all the functions as well.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Alexandre Chartre <alexandre.chartre@xxxxxxxxxx>
Acked-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Acked-by: Andy Lutomirski <luto@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20200505135314.334980426@xxxxxxxxxxxxx

---
arch/x86/entry/entry_32.S | 9 ---------
arch/x86/entry/entry_64.S | 3 ---
arch/x86/include/asm/idtentry.h | 4 ++++
arch/x86/include/asm/mce.h | 2 +-
arch/x86/include/asm/traps.h | 7 -------
arch/x86/kernel/cpu/mce/core.c | 23 ++++++++++++++---------
arch/x86/kernel/cpu/mce/inject.c | 4 ++--
arch/x86/kernel/cpu/mce/internal.h | 2 +-
arch/x86/kernel/cpu/mce/p5.c | 2 +-
arch/x86/kernel/cpu/mce/winchip.c | 2 +-
arch/x86/kernel/idt.c | 10 +++++-----
arch/x86/kvm/vmx/vmx.c | 2 +-
arch/x86/xen/enlighten_pv.c | 2 +-
arch/x86/xen/xen-asm_64.S | 2 +-
14 files changed, 32 insertions(+), 42 deletions(-)

diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index b9b0ddb..4dd3d70 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1297,15 +1297,6 @@ SYM_CODE_START(native_iret)
SYM_CODE_END(native_iret)
#endif

-#ifdef CONFIG_X86_MCE
-SYM_CODE_START(machine_check)
- ASM_CLAC
- pushl $0
- pushl $do_mce
- jmp common_exception
-SYM_CODE_END(machine_check)
-#endif
-
#ifdef CONFIG_XEN_PV
SYM_FUNC_START(xen_hypervisor_callback)
/*
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 69ddd05..5007b97 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1074,9 +1074,6 @@ apicinterrupt IRQ_WORK_VECTOR irq_work_interrupt smp_irq_work_interrupt

idtentry X86_TRAP_PF page_fault do_page_fault has_error_code=1

-#ifdef CONFIG_X86_MCE
-idtentry_mce_db X86_TRAP_MCE machine_check do_mce
-#endif
idtentry_mce_db X86_TRAP_DB debug do_debug
idtentry_df X86_TRAP_DF double_fault do_double_fault

diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 3edd6d0..36fe964 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -238,4 +238,8 @@ DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_AC, exc_alignment_check);
/* Raw exception entries which need extra work */
DECLARE_IDTENTRY_RAW(X86_TRAP_BP, exc_int3);

+#ifdef CONFIG_X86_MCE
+DECLARE_IDTENTRY_MCE(X86_TRAP_MC, exc_machine_check);
+#endif
+
#endif
diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index f9cea08..a001301 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -238,7 +238,7 @@ extern void mce_disable_bank(int bank);
/*
* Exception handler
*/
-void do_machine_check(struct pt_regs *, long);
+void do_machine_check(struct pt_regs *pt_regs);

/*
* Threshold handler
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index 698285a..6096db9 100644
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -18,25 +18,18 @@ asmlinkage void double_fault(void);
#endif
asmlinkage void page_fault(void);
asmlinkage void async_page_fault(void);
-#ifdef CONFIG_X86_MCE
-asmlinkage void machine_check(void);
-#endif /* CONFIG_X86_MCE */

#if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
asmlinkage void xen_xennmi(void);
asmlinkage void xen_xendebug(void);
asmlinkage void xen_double_fault(void);
asmlinkage void xen_page_fault(void);
-#ifdef CONFIG_X86_MCE
-asmlinkage void xen_machine_check(void);
-#endif /* CONFIG_X86_MCE */
#endif

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_double_fault(struct pt_regs *regs, long error_code, unsigned long cr2);
dotraplinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code, unsigned long address);
-dotraplinkage void do_mce(struct pt_regs *regs, long error_code);

#ifdef CONFIG_X86_64
asmlinkage __visible notrace struct pt_regs *sync_regs(struct pt_regs *eregs);
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index f5993ed..842dd03 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1232,7 +1232,7 @@ static void kill_me_maybe(struct callback_head *cb)
* backing the user stack, tracing that reads the user stack will cause
* potentially infinite recursion.
*/
-void noinstr do_machine_check(struct pt_regs *regs, long error_code)
+void noinstr do_machine_check(struct pt_regs *regs)
{
DECLARE_BITMAP(valid_banks, MAX_NR_BANKS);
DECLARE_BITMAP(toclear, MAX_NR_BANKS);
@@ -1366,7 +1366,7 @@ void noinstr do_machine_check(struct pt_regs *regs, long error_code)
current->mce_kill_me.func = kill_me_now;
task_work_add(current, &current->mce_kill_me, true);
} else {
- if (!fixup_exception(regs, X86_TRAP_MC, error_code, 0))
+ if (!fixup_exception(regs, X86_TRAP_MC, 0, 0))
mce_panic("Failed kernel mode recovery", &m, msg);
}
}
@@ -1895,27 +1895,32 @@ bool filter_mce(struct mce *m)
}

/* Handle unconfigured int18 (should never happen) */
-static void unexpected_machine_check(struct pt_regs *regs, long error_code)
+static void unexpected_machine_check(struct pt_regs *regs)
{
pr_err("CPU#%d: Unexpected int18 (Machine Check)\n",
smp_processor_id());
}

/* Call the installed machine check handler for this CPU setup. */
-void (*machine_check_vector)(struct pt_regs *, long error_code) =
- unexpected_machine_check;
+void (*machine_check_vector)(struct pt_regs *) = unexpected_machine_check;

-dotraplinkage noinstr void do_mce(struct pt_regs *regs, long error_code)
+DEFINE_IDTENTRY_MCE(exc_machine_check)
{
if (machine_check_vector == do_machine_check &&
mce_check_crashing_cpu())
return;

- nmi_enter();
+ if (user_mode(regs))
+ idtentry_enter(regs);
+ else
+ nmi_enter();

- machine_check_vector(regs, error_code);
+ machine_check_vector(regs);

- nmi_exit();
+ if (user_mode(regs))
+ idtentry_exit(regs);
+ else
+ nmi_exit();
}

/*
diff --git a/arch/x86/kernel/cpu/mce/inject.c b/arch/x86/kernel/cpu/mce/inject.c
index 3413b41..0593b19 100644
--- a/arch/x86/kernel/cpu/mce/inject.c
+++ b/arch/x86/kernel/cpu/mce/inject.c
@@ -146,9 +146,9 @@ static void raise_exception(struct mce *m, struct pt_regs *pregs)
regs.cs = m->cs;
pregs = &regs;
}
- /* in mcheck exeception handler, irq will be disabled */
+ /* do_machine_check() expects interrupts disabled -- at least */
local_irq_save(flags);
- do_machine_check(pregs, 0);
+ do_machine_check(pregs);
local_irq_restore(flags);
m->finished = 0;
}
diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index 3b00817..b74ca4a 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -9,7 +9,7 @@
#include <asm/mce.h>

/* Pointer to the installed machine check handler for this CPU setup. */
-extern void (*machine_check_vector)(struct pt_regs *, long error_code);
+extern void (*machine_check_vector)(struct pt_regs *);

enum severity_level {
MCE_NO_SEVERITY,
diff --git a/arch/x86/kernel/cpu/mce/p5.c b/arch/x86/kernel/cpu/mce/p5.c
index dc29f0f..eaebc4c 100644
--- a/arch/x86/kernel/cpu/mce/p5.c
+++ b/arch/x86/kernel/cpu/mce/p5.c
@@ -21,7 +21,7 @@
int mce_p5_enabled __read_mostly;

/* Machine check handler for Pentium class Intel CPUs: */
-static void pentium_machine_check(struct pt_regs *regs, long error_code)
+static void pentium_machine_check(struct pt_regs *regs)
{
u32 loaddr, hi, lotype;

diff --git a/arch/x86/kernel/cpu/mce/winchip.c b/arch/x86/kernel/cpu/mce/winchip.c
index 3f8f84b..90e3d60 100644
--- a/arch/x86/kernel/cpu/mce/winchip.c
+++ b/arch/x86/kernel/cpu/mce/winchip.c
@@ -17,7 +17,7 @@
#include "internal.h"

/* Machine check handler for WinChip C6: */
-static void winchip_machine_check(struct pt_regs *regs, long error_code)
+static void winchip_machine_check(struct pt_regs *regs)
{
pr_emerg("CPU0: Machine Check Exception.\n");
add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index 9ca8af6..6b93840 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -96,7 +96,7 @@ static const __initconst struct idt_data def_idts[] = {
INTG(X86_TRAP_DB, debug),

#ifdef CONFIG_X86_MCE
- INTG(X86_TRAP_MC, machine_check),
+ INTG(X86_TRAP_MC, asm_exc_machine_check),
#endif

SYSG(X86_TRAP_OF, asm_exc_overflow),
@@ -185,11 +185,11 @@ gate_desc debug_idt_table[IDT_ENTRIES] __page_aligned_bss;
* 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_NMI, nmi, IST_INDEX_NMI),
- ISTG(X86_TRAP_DF, double_fault, IST_INDEX_DF),
+ ISTG(X86_TRAP_DB, debug, IST_INDEX_DB),
+ ISTG(X86_TRAP_NMI, nmi, IST_INDEX_NMI),
+ ISTG(X86_TRAP_DF, double_fault, IST_INDEX_DF),
#ifdef CONFIG_X86_MCE
- ISTG(X86_TRAP_MC, machine_check, IST_INDEX_MCE),
+ ISTG(X86_TRAP_MC, asm_exc_machine_check, IST_INDEX_MCE),
#endif
};

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index c2c6335..513378c 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4578,7 +4578,7 @@ static void kvm_machine_check(void)
.flags = X86_EFLAGS_IF,
};

- do_machine_check(&regs, 0);
+ do_machine_check(&regs);
#endif
}

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 725d550..f116afe 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -614,7 +614,7 @@ static struct trap_array_entry trap_array[] = {
{ debug, xen_xendebug, true },
{ double_fault, xen_double_fault, true },
#ifdef CONFIG_X86_MCE
- { machine_check, xen_machine_check, true },
+ TRAP_ENTRY(exc_machine_check, true ),
#endif
{ nmi, xen_xennmi, true },
TRAP_ENTRY(exc_int3, false ),
diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
index 44f5556..617ef3f 100644
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -48,7 +48,7 @@ xen_pv_trap asm_exc_spurious_interrupt_bug
xen_pv_trap asm_exc_coprocessor_error
xen_pv_trap asm_exc_alignment_check
#ifdef CONFIG_X86_MCE
-xen_pv_trap machine_check
+xen_pv_trap asm_exc_machine_check
#endif /* CONFIG_X86_MCE */
xen_pv_trap asm_exc_simd_coprocessor_error
#ifdef CONFIG_IA32_EMULATION

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