diff options
author | Harvey Harrison <harvey.harrison@gmail.com> | 2008-01-30 13:31:41 +0100 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:31:41 +0100 |
commit | 6d48583ba9ade609634e694fc35ea62b7a8adaaa (patch) | |
tree | bc6e3bec5359b9136a8e53a9dbe80d71f9795f6b /arch/x86/mm/extable.c | |
parent | 46265df040533f57c191bb2b019d6b25c3bf1f34 (diff) |
x86: unify extable_{32|64}.c
Introduce fixup_exception() on 64-bit and use it in kprobes to
eliminate an #ifdef.
Only 64-bit needs search_extable() due to a stepping bug.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/mm/extable.c')
-rw-r--r-- | arch/x86/mm/extable.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c new file mode 100644 index 00000000000..7e8db53528a --- /dev/null +++ b/arch/x86/mm/extable.c @@ -0,0 +1,62 @@ +#include <linux/module.h> +#include <linux/spinlock.h> +#include <asm/uaccess.h> + + +int fixup_exception(struct pt_regs *regs) +{ + const struct exception_table_entry *fixup; + +#ifdef CONFIG_PNPBIOS + if (unlikely(SEGMENT_IS_PNP_CODE(regs->cs))) { + extern u32 pnp_bios_fault_eip, pnp_bios_fault_esp; + extern u32 pnp_bios_is_utter_crap; + pnp_bios_is_utter_crap = 1; + printk(KERN_CRIT "PNPBIOS fault.. attempting recovery.\n"); + __asm__ volatile( + "movl %0, %%esp\n\t" + "jmp *%1\n\t" + : : "g" (pnp_bios_fault_esp), "g" (pnp_bios_fault_eip)); + panic("do_trap: can't hit this"); + } +#endif + + fixup = search_exception_tables(regs->ip); + if (fixup) { + regs->ip = fixup->fixup; + return 1; + } + + return 0; +} + +#ifdef CONFIG_X86_64 +/* + * Need to defined our own search_extable on X86_64 to work around + * a B stepping K8 bug. + */ +const struct exception_table_entry * +search_extable(const struct exception_table_entry *first, + const struct exception_table_entry *last, + unsigned long value) +{ + /* B stepping K8 bug */ + if ((value >> 32) == 0) + value |= 0xffffffffUL << 32; + + while (first <= last) { + const struct exception_table_entry *mid; + long diff; + + mid = (last - first) / 2 + first; + diff = mid->insn - value; + if (diff == 0) + return mid; + else if (diff < 0) + first = mid+1; + else + last = mid-1; + } + return NULL; +} +#endif |