x86/head: Pass a real pt_regs and trapnr to early_fixup_exception()

[deliverable/linux.git] / arch / x86 / kernel / head_64.S

diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 22fbf9df61bb4eecbb5ffe530562b56c1def90b8..9e8636d2ceddba2d1e3a53ccdc625c9183c86adb 100644 (file)
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -20,6 +20,7 @@
 #include <asm/processor-flags.h>
 #include <asm/percpu.h>
 #include <asm/nops.h>
+#include "../entry/calling.h"
 
 #ifdef CONFIG_PARAVIRT
 #include <asm/asm-offsets.h>
@@ -357,39 +358,52 @@ early_idt_handler_common:
        jz  1f
        incl early_recursion_flag(%rip)
 
-       pushq %rax              # 64(%rsp)
-       pushq %rcx              # 56(%rsp)
-       pushq %rdx              # 48(%rsp)
-       pushq %rsi              # 40(%rsp)
-       pushq %rdi              # 32(%rsp)
-       pushq %r8               # 24(%rsp)
-       pushq %r9               # 16(%rsp)
-       pushq %r10              #  8(%rsp)
-       pushq %r11              #  0(%rsp)
-
-       cmpl $__KERNEL_CS,96(%rsp)
+       /* The vector number is currently in the pt_regs->di slot. */
+       pushq %rsi                              /* pt_regs->si */
+       movq 8(%rsp), %rsi                      /* RSI = vector number */
+       movq %rdi, 8(%rsp)                      /* pt_regs->di = RDI */
+       pushq %rdx                              /* pt_regs->dx */
+       pushq %rcx                              /* pt_regs->cx */
+       pushq %rax                              /* pt_regs->ax */
+       pushq %r8                               /* pt_regs->r8 */
+       pushq %r9                               /* pt_regs->r9 */
+       pushq %r10                              /* pt_regs->r10 */
+       pushq %r11                              /* pt_regs->r11 */
+       pushq %rbx                              /* pt_regs->bx */
+       pushq %rbp                              /* pt_regs->bp */
+       pushq %r12                              /* pt_regs->r12 */
+       pushq %r13                              /* pt_regs->r13 */
+       pushq %r14                              /* pt_regs->r14 */
+       pushq %r15                              /* pt_regs->r15 */
+
+       cmpl $__KERNEL_CS,CS(%rsp)
        jne 11f
 
-       cmpl $14,72(%rsp)       # Page fault?
+       cmpq $14,%rsi           /* Page fault? */
        jnz 10f
-       GET_CR2_INTO(%rdi)      # can clobber any volatile register if pv
+       GET_CR2_INTO(%rdi)      /* Can clobber any volatile register if pv */
        call early_make_pgtable
        andl %eax,%eax
-       jz 20f                  # All good
+       jz 20f                  /* All good */
 
 10:
-       leaq 88(%rsp),%rdi      # Pointer to %rip
+       movq %rsp,%rdi          /* RDI = pt_regs; RSI is already trapnr */
        call early_fixup_exception
        andl %eax,%eax
        jnz 20f                 # Found an exception entry
 
 11:
 #ifdef CONFIG_EARLY_PRINTK
-       GET_CR2_INTO(%r9)       # can clobber any volatile register if pv
-       movl 80(%rsp),%r8d      # error code
-       movl 72(%rsp),%esi      # vector number
-       movl 96(%rsp),%edx      # %cs
-       movq 88(%rsp),%rcx      # %rip
+       /*
+        * On paravirt kernels, GET_CR2_INTO clobbers callee-clobbered regs.
+        * We only care about RSI, so we need to save it.
+        */
+       movq %rsi,%rbx          /* Save vector number */
+       GET_CR2_INTO(%r9)
+       movq ORIG_RAX(%rsp),%r8 /* error code */
+       movq %rbx,%rsi          /* vector number */
+       movq CS(%rsp),%rdx
+       movq RIP(%rsp),%rcx
        xorl %eax,%eax
        leaq early_idt_msg(%rip),%rdi
        call early_printk
@@ -398,24 +412,16 @@ early_idt_handler_common:
        call dump_stack
 #ifdef CONFIG_KALLSYMS 
        leaq early_idt_ripmsg(%rip),%rdi
-       movq 40(%rsp),%rsi      # %rip again
+       movq RIP(%rsp),%rsi     # %rip again
        call __print_symbol
 #endif
 #endif /* EARLY_PRINTK */
 1:     hlt
        jmp 1b
 
-20:    # Exception table entry found or page table generated
-       popq %r11
-       popq %r10
-       popq %r9
-       popq %r8
-       popq %rdi
-       popq %rsi
-       popq %rdx
-       popq %rcx
-       popq %rax
+20:    /* Exception table entry found or page table generated */
        decl early_recursion_flag(%rip)
+       jmp restore_regs_and_iret
 .Lis_nmi:
        addq $16,%rsp           # drop vector number and error code
        INTERRUPT_RETURN