[PATCH 1/2] x86: Shrink some ifdefs in fault.c

From: Harvey Harrison
Date: Thu Jan 24 2008 - 20:05:43 EST


The change from current to tsk in do_page_fault is safe as
this is set at the very beginning of the function.

Removes a likely() annotation from the X86_64 version, this
could have instead been added to X86_32.

Signed-off-by: Harvey Harrison <harvey.harrison@xxxxxxxxx>
---
arch/x86/mm/fault.c | 43 ++++++++++++++-----------------------------
1 files changed, 14 insertions(+), 29 deletions(-)

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 14a0c6e..95fe8bf 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -383,6 +383,7 @@ static void show_fault_oops(struct pt_regs *regs, unsigned long error_code,
#ifdef CONFIG_X86_32
if (!oops_may_print())
return;
+#endif

#ifdef CONFIG_X86_PAE
if (error_code & PF_INSTR) {
@@ -395,28 +396,20 @@ static void show_fault_oops(struct pt_regs *regs, unsigned long error_code,
"(uid: %d)\n", current->uid);
}
#endif
- printk(KERN_ALERT "BUG: unable to handle kernel ");
- if (address < PAGE_SIZE)
- printk(KERN_CONT "NULL pointer dereference");
- else
- printk(KERN_CONT "paging request");
- printk(KERN_CONT " at %08lx\n", address);

- printk(KERN_ALERT "IP:");
- printk_address(regs->ip, 1);
- dump_pagetable(address);
-#else /* CONFIG_X86_64 */
printk(KERN_ALERT "BUG: unable to handle kernel ");
if (address < PAGE_SIZE)
printk(KERN_CONT "NULL pointer dereference");
else
printk(KERN_CONT "paging request");
+#ifdef CONFIG_X86_32
+ printk(KERN_CONT " at %08lx\n", address);
+#else
printk(KERN_CONT " at %016lx\n", address);
-
+#endif
printk(KERN_ALERT "IP:");
printk_address(regs->ip, 1);
dump_pagetable(address);
-#endif
}

#ifdef CONFIG_X86_64
@@ -655,11 +648,7 @@ again:
vma = find_vma(mm, address);
if (!vma)
goto bad_area;
-#ifdef CONFIG_X86_32
if (vma->vm_start <= address)
-#else
- if (likely(vma->vm_start <= address))
-#endif
goto good_area;
if (!(vma->vm_flags & VM_GROWSDOWN))
goto bad_area;
@@ -808,23 +797,21 @@ no_context:
*/
#ifdef CONFIG_X86_32
bust_spinlocks(1);
+#else
+ flags = oops_begin();
+#endif

show_fault_oops(regs, error_code, address);

tsk->thread.cr2 = address;
tsk->thread.trap_no = 14;
tsk->thread.error_code = error_code;
+
+#ifdef CONFIG_X86_32
die("Oops", regs, error_code);
bust_spinlocks(0);
do_exit(SIGKILL);
-#else /* CONFIG_X86_64 */
- flags = oops_begin();
-
- show_fault_oops(regs, error_code, address);
-
- tsk->thread.cr2 = address;
- tsk->thread.trap_no = 14;
- tsk->thread.error_code = error_code;
+#else
if (__die("Oops", regs, error_code))
regs = NULL;
/* Executive summary in case the body of the oops scrolled away */
@@ -838,18 +825,16 @@ no_context:
*/
out_of_memory:
up_read(&mm->mmap_sem);
-#ifdef CONFIG_X86_32
if (is_global_init(tsk)) {
yield();
+#ifdef CONFIG_X86_32
down_read(&mm->mmap_sem);
goto survive;
- }
#else
- if (is_global_init(current)) {
- yield();
goto again;
- }
#endif
+ }
+
printk("VM: killing process %s\n", tsk->comm);
if (error_code & PF_USER)
do_group_exit(SIGKILL);
--
1.5.4.rc4.1130.g9ad85


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