[PATCH] x86: unify extable_{32|64}.c

Harvey Harrison
2007-12-18T10:36:49Z

Introduce fixup_exception() on X86_64 and use it in kprobes to
eliminate an #ifdef.

Only X86_64 needs search_extable() due to a stepping bug.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
---
arch/x86/kernel/kprobes.c | 12 +--------
arch/x86/mm/Makefile_32 | 2 +-
arch/x86/mm/Makefile_64 | 2 +-
arch/x86/mm/extable.c | 62 +++++++++++++++++++++++++++++++++++++++++++++
arch/x86/mm/extable_32.c | 35 -------------------------
arch/x86/mm/extable_64.c | 34 ------------------------
6 files changed, 65 insertions(+), 82 deletions(-)

diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index 1a0d96d..045a45e 100644
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -902,19 +902,9 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
* In case the user-specified fault handler returned
* zero, try to fix up.
*/
-#ifdef CONFIG_X86_64
- {
- const struct exception_table_entry *fixup;
- fixup = search_exception_tables(regs->ip);
- if (fixup) {
- regs->ip = fixup->fixup;
- return 1;
- }
- }
-#else
if (fixup_exception(regs))
return 1;
-#endif
+
/*
* fixup routine could not handle it,
* Let do_page_fault() fix it.
diff --git a/arch/x86/mm/Makefile_32 b/arch/x86/mm/Makefile_32
index a01aca7..6a5e981 100644
--- a/arch/x86/mm/Makefile_32
+++ b/arch/x86/mm/Makefile_32
@@ -2,7 +2,7 @@
# Makefile for the linux i386-specific parts of the memory manager.
#

-obj-y := init_32.o pgtable_32.o fault_32.o ioremap_32.o extable_32.o pageattr_32.o mmap.o
+obj-y := init_32.o pgtable_32.o fault_32.o ioremap_32.o extable.o pageattr_32.o mmap.o

obj-$(CONFIG_NUMA) += discontig_32.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
diff --git a/arch/x86/mm/Makefile_64 b/arch/x86/mm/Makefile_64
index b5a7448..09c997f 100644
--- a/arch/x86/mm/Makefile_64
+++ b/arch/x86/mm/Makefile_64
@@ -2,7 +2,7 @@
# Makefile for the linux x86_64-specific parts of the memory manager.
#

-obj-y := init_64.o fault_64.o ioremap_64.o extable_64.o pageattr_64.o mmap.o
+obj-y := init_64.o fault_64.o ioremap_64.o extable.o pageattr_64.o mmap.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_NUMA) += numa_64.o
obj-$(CONFIG_K8_NUMA) += k8topology_64.o
diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
new file mode 100644
index 0000000..7e8db53
--- /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
diff --git a/arch/x86/mm/extable_32.c b/arch/x86/mm/extable_32.c
deleted file mode 100644
index 4168546..0000000
--- a/arch/x86/mm/extable_32.c
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * linux/arch/i386/mm/extable.c
- */
-
-#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;
-}
diff --git a/arch/x86/mm/extable_64.c b/arch/x86/mm/extable_64.c
deleted file mode 100644
index 79ac6e7..0000000
--- a/arch/x86/mm/extable_64.c
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * linux/arch/x86_64/mm/extable.c
- */
-
-#include <linux/module.h>
-#include <linux/spinlock.h>
-#include <linux/init.h>
-#include <asm/uaccess.h>
-
-/* Simple binary search */
-const struct exception_table_entry *
-search_extable(const struct exception_table_entry *first,
- const struct exception_table_entry *last,
- unsigned long value)
-{
- /* Work around a 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;
-}
--
1.5.4.rc0.1143.g1a8a