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Diffstat (limited to 'arch/avr32/mm/fault.c')
-rw-r--r--arch/avr32/mm/fault.c125
1 files changed, 55 insertions, 70 deletions
diff --git a/arch/avr32/mm/fault.c b/arch/avr32/mm/fault.c
index 88b00b15970..0eca9332719 100644
--- a/arch/avr32/mm/fault.c
+++ b/arch/avr32/mm/fault.c
@@ -12,41 +12,30 @@
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/pagemap.h>
-
#include <linux/kdebug.h>
+#include <linux/kprobes.h>
+
#include <asm/mmu_context.h>
#include <asm/sysreg.h>
#include <asm/tlb.h>
#include <asm/uaccess.h>
#ifdef CONFIG_KPROBES
-ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
-
-/* Hook to register for page fault notifications */
-int register_page_fault_notifier(struct notifier_block *nb)
+static inline int notify_page_fault(struct pt_regs *regs, int trap)
{
- return atomic_notifier_chain_register(&notify_page_fault_chain, nb);
-}
+ int ret = 0;
-int unregister_page_fault_notifier(struct notifier_block *nb)
-{
- return atomic_notifier_chain_unregister(&notify_page_fault_chain, nb);
-}
+ if (!user_mode(regs)) {
+ if (kprobe_running() && kprobe_fault_handler(regs, trap))
+ ret = 1;
+ }
-static inline int notify_page_fault(enum die_val val, struct pt_regs *regs,
- int trap, int sig)
-{
- struct die_args args = {
- .regs = regs,
- .trapnr = trap,
- };
- return atomic_notifier_call_chain(&notify_page_fault_chain, val, &args);
+ return ret;
}
#else
-static inline int notify_page_fault(enum die_val val, struct pt_regs *regs,
- int trap, int sig)
+static inline int notify_page_fault(struct pt_regs *regs, int trap)
{
- return NOTIFY_DONE;
+ return 0;
}
#endif
@@ -72,12 +61,12 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
const struct exception_table_entry *fixup;
unsigned long address;
unsigned long page;
- int writeaccess;
long signr;
int code;
+ int fault;
+ unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
- if (notify_page_fault(DIE_PAGE_FAULT, regs,
- ecr, SIGSEGV) == NOTIFY_STOP)
+ if (notify_page_fault(regs, ecr))
return;
address = sysreg_read(TLBEAR);
@@ -97,6 +86,9 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
local_irq_enable();
+ if (user_mode(regs))
+ flags |= FAULT_FLAG_USER;
+retry:
down_read(&mm->mmap_sem);
vma = find_vma(mm, address);
@@ -115,7 +107,6 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
*/
good_area:
code = SEGV_ACCERR;
- writeaccess = 0;
switch (ecr) {
case ECR_PROTECTION_X:
@@ -132,7 +123,7 @@ good_area:
case ECR_TLB_MISS_W:
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
- writeaccess = 1;
+ flags |= FAULT_FLAG_WRITE;
break;
default:
panic("Unhandled case %lu in do_page_fault!", ecr);
@@ -143,22 +134,37 @@ good_area:
* sure we exit gracefully rather than endlessly redo the
* fault.
*/
-survive:
- switch (handle_mm_fault(mm, vma, address, writeaccess)) {
- case VM_FAULT_MINOR:
- tsk->min_flt++;
- break;
- case VM_FAULT_MAJOR:
- tsk->maj_flt++;
- break;
- case VM_FAULT_SIGBUS:
- goto do_sigbus;
- case VM_FAULT_OOM:
- goto out_of_memory;
- default:
+ fault = handle_mm_fault(mm, vma, address, flags);
+
+ if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
+ return;
+
+ if (unlikely(fault & VM_FAULT_ERROR)) {
+ if (fault & VM_FAULT_OOM)
+ goto out_of_memory;
+ else if (fault & VM_FAULT_SIGBUS)
+ goto do_sigbus;
BUG();
}
+ if (flags & FAULT_FLAG_ALLOW_RETRY) {
+ if (fault & VM_FAULT_MAJOR)
+ tsk->maj_flt++;
+ else
+ tsk->min_flt++;
+ if (fault & VM_FAULT_RETRY) {
+ flags &= ~FAULT_FLAG_ALLOW_RETRY;
+ flags |= FAULT_FLAG_TRIED;
+
+ /*
+ * No need to up_read(&mm->mmap_sem) as we would have
+ * already released it in __lock_page_or_retry() in
+ * mm/filemap.c.
+ */
+ goto retry;
+ }
+ }
+
up_read(&mm->mmap_sem);
return;
@@ -170,10 +176,10 @@ bad_area:
up_read(&mm->mmap_sem);
if (user_mode(regs)) {
- if (exception_trace)
+ if (exception_trace && printk_ratelimit())
printk("%s%s[%d]: segfault at %08lx pc %08lx "
"sp %08lx ecr %lu\n",
- is_init(tsk) ? KERN_EMERG : KERN_INFO,
+ is_global_init(tsk) ? KERN_EMERG : KERN_INFO,
tsk->comm, tsk->pid, address, regs->pc,
regs->sp, ecr);
_exception(SIGSEGV, regs, code, address);
@@ -202,6 +208,8 @@ no_context:
page = sysreg_read(PTBR);
printk(KERN_ALERT "ptbr = %08lx", page);
+ if (address >= TASK_SIZE)
+ page = (unsigned long)swapper_pg_dir;
if (page) {
page = ((unsigned long *)page)[address >> 22];
printk(" pgd = %08lx", page);
@@ -222,15 +230,10 @@ no_context:
*/
out_of_memory:
up_read(&mm->mmap_sem);
- if (is_init(current)) {
- yield();
- down_read(&mm->mmap_sem);
- goto survive;
- }
- printk("VM: Killing process %s\n", tsk->comm);
- if (user_mode(regs))
- do_exit(SIGKILL);
- goto no_context;
+ if (!user_mode(regs))
+ goto no_context;
+ pagefault_out_of_memory();
+ return;
do_sigbus:
up_read(&mm->mmap_sem);
@@ -244,7 +247,7 @@ do_sigbus:
if (exception_trace)
printk("%s%s[%d]: bus error at %08lx pc %08lx "
"sp %08lx ecr %lu\n",
- is_init(tsk) ? KERN_EMERG : KERN_INFO,
+ is_global_init(tsk) ? KERN_EMERG : KERN_INFO,
tsk->comm, tsk->pid, address, regs->pc,
regs->sp, ecr);
@@ -261,21 +264,3 @@ asmlinkage void do_bus_error(unsigned long addr, int write_access,
dump_dtlb();
die("Bus Error", regs, SIGKILL);
}
-
-/*
- * This functionality is currently not possible to implement because
- * we're using segmentation to ensure a fixed mapping of the kernel
- * virtual address space.
- *
- * It would be possible to implement this, but it would require us to
- * disable segmentation at startup and load the kernel mappings into
- * the TLB like any other pages. There will be lots of trickery to
- * avoid recursive invocation of the TLB miss handler, though...
- */
-#ifdef CONFIG_DEBUG_PAGEALLOC
-void kernel_map_pages(struct page *page, int numpages, int enable)
-{
-
-}
-EXPORT_SYMBOL(kernel_map_pages);
-#endif
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-11 15:59:16 +0000