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authorAndy Lutomirski <luto@kernel.org>2016-04-02 07:01:32 -0700
committerIngo Molnar <mingo@kernel.org>2016-04-13 11:37:44 +0200
commit7bbcdb1ca4d2fd69094ee89c18601b396531ca9f (patch)
treed8a117babfa869335321285012d7862d96bf7af1 /arch/x86/kernel/head_32.S
parent6aa6dbfced51dec6cde159c6167ad3dad6add823 (diff)
x86/head: Pass a real pt_regs and trapnr to early_fixup_exception()
early_fixup_exception() is limited by the fact that it doesn't have a real struct pt_regs. Change both the 32-bit and 64-bit asm and the C code to pass and accept a real pt_regs. Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: KVM list <kvm@vger.kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel <Xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/e3fb680fcfd5e23e38237e8328b64a25cc121d37.1459605520.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/head_32.S')
-rw-r--r--arch/x86/kernel/head_32.S74
1 files changed, 51 insertions, 23 deletions
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 54cdbd2003fe..0904536cd45c 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -568,29 +568,64 @@ early_idt_handler_common:
je hlt_loop
incl %ss:early_recursion_flag
- push %eax # 16(%esp)
- push %ecx # 12(%esp)
- push %edx # 8(%esp)
- push %ds # 4(%esp)
- push %es # 0(%esp)
- movl $(__KERNEL_DS),%eax
- movl %eax,%ds
- movl %eax,%es
+ /* The vector number is in pt_regs->gs */
- cmpl $(__KERNEL_CS),32(%esp)
+ cld
+ pushl %fs /* pt_regs->fs */
+ movw $0, 2(%esp) /* clear high bits (some CPUs leave garbage) */
+ pushl %es /* pt_regs->es */
+ movw $0, 2(%esp) /* clear high bits (some CPUs leave garbage) */
+ pushl %ds /* pt_regs->ds */
+ movw $0, 2(%esp) /* clear high bits (some CPUs leave garbage) */
+ pushl %eax /* pt_regs->ax */
+ pushl %ebp /* pt_regs->bp */
+ pushl %edi /* pt_regs->di */
+ pushl %esi /* pt_regs->si */
+ pushl %edx /* pt_regs->dx */
+ pushl %ecx /* pt_regs->cx */
+ pushl %ebx /* pt_regs->bx */
+
+ /* Fix up DS and ES */
+ movl $(__KERNEL_DS), %ecx
+ movl %ecx, %ds
+ movl %ecx, %es
+
+ /* Load the vector number into EDX */
+ movl PT_GS(%esp), %edx
+
+ /* Load GS into pt_regs->gs and clear high bits */
+ movw %gs, PT_GS(%esp)
+ movw $0, PT_GS+2(%esp)
+
+ cmpl $(__KERNEL_CS),PT_CS(%esp)
jne 10f
- leal 28(%esp),%eax # Pointer to %eip
- call early_fixup_exception
- andl %eax,%eax
- jnz ex_entry /* found an exception entry */
+ movl %esp, %eax /* args are pt_regs (EAX), trapnr (EDX) */
+ call early_fixup_exception
+ andl %eax,%eax
+ jz 10f /* Exception wasn't fixed up */
+
+ popl %ebx /* pt_regs->bx */
+ popl %ecx /* pt_regs->cx */
+ popl %edx /* pt_regs->dx */
+ popl %esi /* pt_regs->si */
+ popl %edi /* pt_regs->di */
+ popl %ebp /* pt_regs->bp */
+ popl %eax /* pt_regs->ax */
+ popl %ds /* pt_regs->ds */
+ popl %es /* pt_regs->es */
+ popl %fs /* pt_regs->fs */
+ popl %gs /* pt_regs->gs */
+ decl %ss:early_recursion_flag
+ addl $4, %esp /* pop pt_regs->orig_ax */
+ iret
10:
#ifdef CONFIG_PRINTK
xorl %eax,%eax
- movw %ax,2(%esp) /* clean up the segment values on some cpus */
- movw %ax,6(%esp)
- movw %ax,34(%esp)
+ movw %ax,PT_FS+2(%esp) /* clean up the segment values on some cpus */
+ movw %ax,PT_DS+2(%esp)
+ movw %ax,PT_ES+2(%esp)
leal 40(%esp),%eax
pushl %eax /* %esp before the exception */
pushl %ebx
@@ -608,13 +643,6 @@ hlt_loop:
hlt
jmp hlt_loop
-ex_entry:
- pop %es
- pop %ds
- pop %edx
- pop %ecx
- pop %eax
- decl %ss:early_recursion_flag
.Lis_nmi:
addl $8,%esp /* drop vector number and error code */
iret