Prev: [PATCH 5/5] x86-32: Don't set ignore_fpu_irq in simd exception
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From: Brian Gerst on 18 Mar 2010 14:30
Make the cache flush handler a seperate function, and use
an alternative to call the appropriate handler.

Signed-off-by: Brian Gerst <brgerst(a)gmail.com>
---
arch/x86/kernel/entry_32.S | 16 +++++++++++++++-
arch/x86/kernel/traps.c | 43 ++++++++++++++++++++++++-------------------
2 files changed, 39 insertions(+), 20 deletions(-)

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 44a8e0d..c3769fa 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -53,6 +53,7 @@
#include <asm/processor-flags.h>
#include <asm/ftrace.h>
#include <asm/irq_vectors.h>
+#include <asm/cpufeature.h>

/* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */
#include <linux/elf-em.h>
@@ -905,7 +906,20 @@ ENTRY(simd_coprocessor_error)
RING0_INT_FRAME
pushl $0
CFI_ADJUST_CFA_OFFSET 4
- pushl $do_simd_coprocessor_error
+661: pushl $do_cache_flush_error
+662:
+.section .altinstructions,"a"
+ ALIGN
+ .long 661b
+ .long 663f
+ .byte X86_FEATURE_XMM
+ .byte 662b-661b
+ .byte 664f-663f
+.previous
+.section .altinstr_replacement,"ax"
+663: pushl $do_simd_coprocessor_error
+664:
+.previous
CFI_ADJUST_CFA_OFFSET 4
jmp error_code
CFI_ENDPROC
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 1168e44..45b9cb0 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -257,6 +257,27 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
}
#endif

+#ifdef CONFIG_X86_32
+dotraplinkage void
+do_cache_flush_error(struct pt_regs *regs, long error_code)
+{
+ conditional_sti(regs);
+
+ /*
+ * Handle strange cache flush from user space exception.
+ * This is undocumented behaviour.
+ */
+ if (regs->flags & X86_VM_MASK) {
+ handle_vm86_fault((struct kernel_vm86_regs *)regs, error_code);
+ return;
+ }
+ current->thread.trap_no = 19;
+ current->thread.error_code = error_code;
+ die_if_kernel("cache flush denied", regs, error_code);
+ force_sig(SIGSEGV, current);
+}
+#endif
+
dotraplinkage void __kprobes
do_general_protection(struct pt_regs *regs, long error_code)
{
@@ -729,30 +750,14 @@ do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
conditional_sti(regs);

#ifdef CONFIG_X86_32
- if (cpu_has_xmm) {
- /* Handle SIMD FPU exceptions on PIII+ processors. */
- ignore_fpu_irq = 1;
- simd_math_error((void __user *)regs->ip);
- return;
- }
- /*
- * Handle strange cache flush from user space exception
- * in all other cases. This is undocumented behaviour.
- */
- if (regs->flags & X86_VM_MASK) {
- handle_vm86_fault((struct kernel_vm86_regs *)regs, error_code);
- return;
- }
- current->thread.trap_no = 19;
- current->thread.error_code = error_code;
- die_if_kernel("cache flush denied", regs, error_code);
- force_sig(SIGSEGV, current);
+ ignore_fpu_irq = 1;
#else
if (!user_mode(regs) &&
kernel_math_error(regs, "kernel simd math error", 19))
return;
- simd_math_error((void __user *)regs->ip);
#endif
+
+ simd_math_error((void __user *)regs->ip);
}

dotraplinkage void
--
1.6.6.1

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