It's not too pretty, but I found this made the "PANIC: early exception"
messages become much more reliably useful: 1. print the vector number,
2. print the %cs value, 3. handle error-code-pushing vs non-pushing vectors.
Signed-off-by: Roland McGrath <[EMAIL PROTECTED]>
---
arch/x86/kernel/head64.c | 6 ++++--
arch/x86/kernel/head_64.S | 34 ++++++++++++++++++++++++++++++----
2 files changed, 34 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 4a1c135..0000000 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -48,6 +48,8 @@ static void __init copy_bootdata(char *r
}
}
+extern const char early_idt_handlers[IDT_ENTRIES][10];
+
void __init x86_64_start_kernel(char * real_mode_data)
{
int i;
@@ -59,7 +61,7 @@ void __init x86_64_start_kernel(char * r
zap_identity_mappings();
for (i = 0; i < IDT_ENTRIES; i++)
- set_intr_gate(i, early_idt_handler);
+ set_intr_gate(i, &early_idt_handlers[i]);
load_idt((const struct desc_ptr *)&idt_descr);
early_printk("Kernel alive\n");
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index c31b1c9..0000000 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -267,14 +267,40 @@ init_rsp:
bad_address:
jmp bad_address
+.macro early_idt_tramp first, last
+ .ifgt \last-\first
+ early_idt_tramp \first, \last-1
+ .endif
+ movl $\last,%esi
+ jmp early_idt_handler
+.endm
+
+ .globl early_idt_handlers
+early_idt_handlers:
+ early_idt_tramp 0, 63
+ early_idt_tramp 64, 127
+ early_idt_tramp 128, 191
+ early_idt_tramp 192, 255
+
ENTRY(early_idt_handler)
cmpl $2,early_recursion_flag(%rip)
jz 1f
incl early_recursion_flag(%rip)
- xorl %eax,%eax
- movq 8(%rsp),%rsi # get rip
- movq (%rsp),%rdx
GET_CR2_INTO_RCX
+ movq %rcx,%r9
+ xorl %r8d,%r8d # zero for error code
+ movl %esi,%ecx # get vector number
+ # Test %ecx against mask of vectors that push error code.
+ cmpl $31,%ecx
+ ja 0f
+ movl $1,%eax
+ salq %cl,%rax
+ testl $0x27d00,%eax
+ je 0f
+ popq %r8 # get error code
+0: movq 0(%rsp),%rcx # get ip
+ movq 8(%rsp),%rdx # get cs
+ xorl %eax,%eax
leaq early_idt_msg(%rip),%rdi
call early_printk
cmpl $2,early_recursion_flag(%rip)
@@ -291,7 +317,7 @@ early_recursion_flag:
.long 0
early_idt_msg:
- .asciz "PANIC: early exception rip %lx error %lx cr2 %lx\n"
+ .asciz "PANIC: early exception %02lx rip %lx:%lx error %lx cr2 %lx\n"
early_idt_ripmsg:
.asciz "RIP %s\n"
--
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