[tip: x86/entry] x86/entry: Convert Bounds exception to IDTENTRY

tip-bot2 for Thomas Gleixner
2020-05-19T19:58:59Z

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

Commit-ID: e98b41399cb15d8e52e266b53e32f1362f541daf
Gitweb: https://git.kernel.org/tip/e98b41399cb15d8e52e266b53e32f1362f541daf
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 25 Feb 2020 23:16:17 +01:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Tue, 19 May 2020 16:03:58 +02:00

x86/entry: Convert Bounds exception to IDTENTRY

Convert #BR 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 prototypes
- Remove the RCU warning as the new entry macro ensures correctness

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200505134904.863001309@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 | 9 ++++-----
arch/x86/xen/enlighten_pv.c | 2 +-
arch/x86/xen/xen-asm_64.S | 2 +-
8 files changed, 8 insertions(+), 19 deletions(-)

diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index e5d57f6..31a64df 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1325,13 +1325,6 @@ SYM_CODE_START(native_iret)
SYM_CODE_END(native_iret)
#endif

-SYM_CODE_START(bounds)
- ASM_CLAC
- pushl $0
- pushl $do_bounds
- jmp common_exception
-SYM_CODE_END(bounds)
-
SYM_CODE_START(invalid_op)
ASM_CLAC
pushl $0
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index eb503b0..a3e484d 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_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
idtentry X86_TRAP_OLD_MF coprocessor_segment_overrun do_coprocessor_segment_overrun has_error_code=0
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 54c41b3..d7c160b 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -79,5 +79,6 @@ static __always_inline void __##func(struct pt_regs *regs)
/* Simple exception entry points. No hardware error code */
DECLARE_IDTENTRY(X86_TRAP_DE, exc_divide_error);
DECLARE_IDTENTRY(X86_TRAP_OF, exc_overflow);
+DECLARE_IDTENTRY(X86_TRAP_BR, exc_bounds);

#endif
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index 1b0452c..73fe4eb 100644
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -14,7 +14,6 @@
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);
#ifdef CONFIG_X86_64
@@ -39,7 +38,6 @@ asmlinkage void simd_coprocessor_error(void);
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);
asmlinkage void xen_double_fault(void);
@@ -61,7 +59,6 @@ asmlinkage void xen_simd_coprocessor_error(void);
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);
dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsigned long cr2);
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index f8d7962..87583b6 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -75,7 +75,7 @@ static const __initconst struct idt_data early_idts[] = {
static const __initconst struct idt_data def_idts[] = {
INTG(X86_TRAP_DE, asm_exc_divide_error),
INTG(X86_TRAP_NMI, nmi),
- INTG(X86_TRAP_BR, bounds),
+ INTG(X86_TRAP_BR, asm_exc_bounds),
INTG(X86_TRAP_UD, invalid_op),
INTG(X86_TRAP_NM, device_not_available),
INTG(X86_TRAP_OLD_MF, coprocessor_segment_overrun),
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index b522e2a..7a9fb8b 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -410,18 +410,17 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsign
panic("Machine halted.");
}

-dotraplinkage void do_bounds(struct pt_regs *regs, long error_code)
+DEFINE_IDTENTRY(exc_bounds)
{
- RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
- if (notify_die(DIE_TRAP, "bounds", regs, error_code,
+ if (notify_die(DIE_TRAP, "bounds", regs, 0,
X86_TRAP_BR, SIGSEGV) == NOTIFY_STOP)
return;
cond_local_irq_enable(regs);

if (!user_mode(regs))
- die("bounds", regs, error_code);
+ die("bounds", regs, 0);

- do_trap(X86_TRAP_BR, SIGSEGV, "bounds", regs, error_code, 0, NULL);
+ do_trap(X86_TRAP_BR, SIGSEGV, "bounds", regs, 0, 0, NULL);

cond_local_irq_disable(regs);
}
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index f5487e5..dfb4baa 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -624,7 +624,7 @@ static struct trap_array_entry trap_array[] = {
#endif
{ page_fault, xen_page_fault, false },
TRAP_ENTRY(exc_divide_error, false ),
- { bounds, xen_bounds, false },
+ TRAP_ENTRY(exc_bounds, false ),
{ invalid_op, xen_invalid_op, false },
{ device_not_available, xen_device_not_available, false },
{ coprocessor_segment_overrun, xen_coprocessor_segment_overrun, false },
diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
index c9c86a0..2cdbf6a 100644
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -34,7 +34,7 @@ xen_pv_trap xendebug
xen_pv_trap int3
xen_pv_trap xennmi
xen_pv_trap asm_exc_overflow
-xen_pv_trap bounds
+xen_pv_trap asm_exc_bounds
xen_pv_trap invalid_op
xen_pv_trap device_not_available
xen_pv_trap double_fault