[tip: x86/entry] x86/entry: Convert SIMD coprocessor error exception to IDTENTRY

From: tip-bot2 for Thomas Gleixner
Date: Tue May 19 2020 - 16:02:12 EST

Next message: tip-bot2 for Thomas Gleixner: "[tip: x86/entry] x86/entry: Convert INT3 exception to IDTENTRY_RAW"
Previous message: tip-bot2 for Thomas Gleixner: "[tip: x86/entry] x86/int3: Ensure that poke_int3_handler() is not traced"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

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

Commit-ID: 03852142b159a78c77aa795ba6c6bd1f6273eab8
Gitweb: https://git.kernel.org/tip/03852142b159a78c77aa795ba6c6bd1f6273eab8
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Tue, 25 Feb 2020 23:16:29 +01:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Tue, 19 May 2020 16:04:03 +02:00

x86/entry: Convert SIMD coprocessor error exception to IDTENTRY

Convert #XF to IDTENTRY_ERRORCODE:
- Implement the C entry point with DEFINE_IDTENTRY
- Emit the ASM stub with DECLARE_IDTENTRY
- Handle INVD_BUG in C
- 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 RCU warning as the new entry macro ensures correctness

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/20200505134906.021552202@xxxxxxxxxxxxx

---
arch/x86/entry/entry_32.S | 14 --------------
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 | 29 +++++++++++++++++------------
arch/x86/xen/enlighten_pv.c | 2 +-
arch/x86/xen/xen-asm_64.S | 2 +-
8 files changed, 21 insertions(+), 33 deletions(-)

diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 7402890..c93fb73 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1290,20 +1290,6 @@ SYM_FUNC_END(name)
/* The include is where all of the SMP etc. interrupts come from */
#include <asm/entry_arch.h>

-SYM_CODE_START(simd_coprocessor_error)
- ASM_CLAC
- pushl $0
-#ifdef CONFIG_X86_INVD_BUG
- /* AMD 486 bug: invd from userspace calls exception 19 instead of #GP */
- ALTERNATIVE "pushl $exc_general_protection", \
- "pushl $do_simd_coprocessor_error", \
- X86_FEATURE_XMM
-#else
- pushl $do_simd_coprocessor_error
-#endif
- jmp common_exception
-SYM_CODE_END(simd_coprocessor_error)
-
#ifdef CONFIG_PARAVIRT
SYM_CODE_START(native_iret)
iret
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 3c95a63..1bada7b 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_XF simd_coprocessor_error do_simd_coprocessor_error has_error_code=0

idtentry X86_TRAP_PF page_fault do_page_fault has_error_code=1

diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 531dbc0..99d4759 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -131,6 +131,7 @@ DECLARE_IDTENTRY(X86_TRAP_NM, exc_device_not_available);
DECLARE_IDTENTRY(X86_TRAP_OLD_MF, exc_coproc_segment_overrun);
DECLARE_IDTENTRY(X86_TRAP_SPURIOUS, exc_spurious_interrupt_bug);
DECLARE_IDTENTRY(X86_TRAP_MF, exc_coprocessor_error);
+DECLARE_IDTENTRY(X86_TRAP_XF, exc_simd_coprocessor_error);

/* Simple exception entries with error code pushed by hardware */
DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_TS, exc_invalid_tss);
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index 0f755e1..e7eb753 100644
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -22,7 +22,6 @@ asmlinkage void async_page_fault(void);
#ifdef CONFIG_X86_MCE
asmlinkage void machine_check(void);
#endif /* CONFIG_X86_MCE */
-asmlinkage void simd_coprocessor_error(void);

#if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
asmlinkage void xen_xennmi(void);
@@ -33,7 +32,6 @@ asmlinkage void xen_page_fault(void);
#ifdef CONFIG_X86_MCE
asmlinkage void xen_machine_check(void);
#endif /* CONFIG_X86_MCE */
-asmlinkage void xen_simd_coprocessor_error(void);
#endif

dotraplinkage void do_debug(struct pt_regs *regs, long error_code);
@@ -41,7 +39,6 @@ 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_page_fault(struct pt_regs *regs, unsigned long error_code, unsigned long address);
-dotraplinkage void do_simd_coprocessor_error(struct pt_regs *regs, long error_code);
#ifdef CONFIG_X86_32
dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code);
#endif
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index af48196..38b565b 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -86,7 +86,7 @@ static const __initconst struct idt_data def_idts[] = {
INTG(X86_TRAP_SPURIOUS, asm_exc_spurious_interrupt_bug),
INTG(X86_TRAP_MF, asm_exc_coprocessor_error),
INTG(X86_TRAP_AC, asm_exc_alignment_check),
- INTG(X86_TRAP_XF, simd_coprocessor_error),
+ INTG(X86_TRAP_XF, asm_exc_simd_coprocessor_error),

#ifdef CONFIG_X86_32
TSKG(X86_TRAP_DF, GDT_ENTRY_DOUBLEFAULT_TSS),
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 9f156c8..1702922 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -810,7 +810,7 @@ NOKPROBE_SYMBOL(do_debug);
* the correct behaviour even in the presence of the asynchronous
* IRQ13 behaviour
*/
-static void math_error(struct pt_regs *regs, int error_code, int trapnr)
+static void math_error(struct pt_regs *regs, int trapnr)
{
struct task_struct *task = current;
struct fpu *fpu = &task->thread.fpu;
@@ -821,15 +821,15 @@ static void math_error(struct pt_regs *regs, int error_code, int trapnr)
cond_local_irq_enable(regs);

if (!user_mode(regs)) {
- if (fixup_exception(regs, trapnr, error_code, 0))
+ if (fixup_exception(regs, trapnr, 0, 0))
goto exit;

- task->thread.error_code = error_code;
+ task->thread.error_code = 0;
task->thread.trap_nr = trapnr;

- if (notify_die(DIE_TRAP, str, regs, error_code,
- trapnr, SIGFPE) != NOTIFY_STOP)
- die(str, regs, error_code);
+ if (notify_die(DIE_TRAP, str, regs, 0, trapnr,
+ SIGFPE) != NOTIFY_STOP)
+ die(str, regs, 0);
goto exit;
}

@@ -839,7 +839,7 @@ static void math_error(struct pt_regs *regs, int error_code, int trapnr)
fpu__save(fpu);

task->thread.trap_nr = trapnr;
- task->thread.error_code = error_code;
+ task->thread.error_code = 0;

si_code = fpu__exception_code(fpu, trapnr);
/* Retry when we get spurious exceptions: */
@@ -854,14 +854,19 @@ exit:

DEFINE_IDTENTRY(exc_coprocessor_error)
{
- math_error(regs, 0, X86_TRAP_MF);
+ math_error(regs, X86_TRAP_MF);
}

-dotraplinkage void
-do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
+DEFINE_IDTENTRY(exc_simd_coprocessor_error)
{
- RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
- math_error(regs, error_code, X86_TRAP_XF);
+ if (IS_ENABLED(CONFIG_X86_INVD_BUG)) {
+ /* AMD 486 bug: INVD in CPL 0 raises #XF instead of #GP */
+ if (!static_cpu_has(X86_FEATURE_XMM)) {
+ __exc_general_protection(regs, 0);
+ return;
+ }
+ }
+ math_error(regs, X86_TRAP_XF);
}

DEFINE_IDTENTRY(exc_spurious_interrupt_bug)
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index afe12d9..c41152b 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -635,7 +635,7 @@ static struct trap_array_entry trap_array[] = {
TRAP_ENTRY(exc_spurious_interrupt_bug, false ),
TRAP_ENTRY(exc_coprocessor_error, false ),
TRAP_ENTRY(exc_alignment_check, false ),
- { simd_coprocessor_error, xen_simd_coprocessor_error, false },
+ TRAP_ENTRY(exc_simd_coprocessor_error, false ),
};

static bool __ref get_trap_addr(void **addr, unsigned int ist)
diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
index a591bec..6a91157 100644
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -50,7 +50,7 @@ xen_pv_trap asm_exc_alignment_check
#ifdef CONFIG_X86_MCE
xen_pv_trap machine_check
#endif /* CONFIG_X86_MCE */
-xen_pv_trap simd_coprocessor_error
+xen_pv_trap asm_exc_simd_coprocessor_error
#ifdef CONFIG_IA32_EMULATION
xen_pv_trap entry_INT80_compat
#endif

Next message: tip-bot2 for Thomas Gleixner: "[tip: x86/entry] x86/entry: Convert INT3 exception to IDTENTRY_RAW"
Previous message: tip-bot2 for Thomas Gleixner: "[tip: x86/entry] x86/int3: Ensure that poke_int3_handler() is not traced"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]