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Diffstat (limited to 'arch/microblaze/mm/fault.c')
-rw-r--r--arch/microblaze/mm/fault.c101
1 files changed, 53 insertions, 48 deletions
diff --git a/arch/microblaze/mm/fault.c b/arch/microblaze/mm/fault.c
index d9d249a66ff..fa4cf52aa7a 100644
--- a/arch/microblaze/mm/fault.c
+++ b/arch/microblaze/mm/fault.c
@@ -32,15 +32,10 @@
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
-#include <asm/mmu_context.h>
-#include <asm/system.h>
+#include <linux/mmu_context.h>
#include <linux/uaccess.h>
#include <asm/exceptions.h>
-#if defined(CONFIG_KGDB)
-int debugger_kernel_faults = 1;
-#endif
-
static unsigned long pte_misses; /* updated by do_page_fault() */
static unsigned long pte_errors; /* updated by do_page_fault() */
@@ -52,7 +47,7 @@ static int store_updates_sp(struct pt_regs *regs)
{
unsigned int inst;
- if (get_user(inst, (unsigned int *)regs->pc))
+ if (get_user(inst, (unsigned int __user *)regs->pc))
return 0;
/* check for 1 in the rD field */
if (((inst >> 21) & 0x1f) != 1)
@@ -81,10 +76,6 @@ void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
}
/* kernel has accessed a bad area */
-#if defined(CONFIG_KGDB)
- if (debugger_kernel_faults)
- debugger(regs);
-#endif
die("kernel access of bad area", regs, sig);
}
@@ -101,13 +92,14 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
int code = SEGV_MAPERR;
int is_write = error_code & ESR_S;
int fault;
+ unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
regs->ear = address;
regs->esr = error_code;
/* On a kernel SLB miss we can only check for a valid exception entry */
- if (kernel_mode(regs) && (address >= TASK_SIZE)) {
- printk(KERN_WARNING "kernel task_size exceed");
+ if (unlikely(kernel_mode(regs) && (address >= TASK_SIZE))) {
+ pr_warn("kernel task_size exceed");
_exception(SIGSEGV, regs, code, address);
}
@@ -115,26 +107,22 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
if ((error_code & 0x13) == 0x13 || (error_code & 0x11) == 0x11)
is_write = 0;
-#if defined(CONFIG_KGDB)
- if (debugger_fault_handler && regs->trap == 0x300) {
- debugger_fault_handler(regs);
- return;
- }
-#endif /* CONFIG_KGDB */
-
- if (in_atomic() || !mm) {
+ if (unlikely(in_atomic() || !mm)) {
if (kernel_mode(regs))
goto bad_area_nosemaphore;
/* in_atomic() in user mode is really bad,
as is current->mm == NULL. */
- printk(KERN_EMERG "Page fault in user mode with "
- "in_atomic(), mm = %p\n", mm);
- printk(KERN_EMERG "r15 = %lx MSR = %lx\n",
+ pr_emerg("Page fault in user mode with in_atomic(), mm = %p\n",
+ mm);
+ pr_emerg("r15 = %lx MSR = %lx\n",
regs->r15, regs->msr);
die("Weird page fault", regs, SIGSEGV);
}
+ if (user_mode(regs))
+ flags |= FAULT_FLAG_USER;
+
/* When running in the kernel we expect faults to occur only to
* addresses in user space. All other faults represent errors in the
* kernel and should generate an OOPS. Unfortunately, in the case of an
@@ -150,24 +138,25 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
* source. If this is invalid we can skip the address space check,
* thus avoiding the deadlock.
*/
- if (!down_read_trylock(&mm->mmap_sem)) {
+ if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
if (kernel_mode(regs) && !search_exception_tables(regs->pc))
goto bad_area_nosemaphore;
+retry:
down_read(&mm->mmap_sem);
}
vma = find_vma(mm, address);
- if (!vma)
+ if (unlikely(!vma))
goto bad_area;
if (vma->vm_start <= address)
goto good_area;
- if (!(vma->vm_flags & VM_GROWSDOWN))
+ if (unlikely(!(vma->vm_flags & VM_GROWSDOWN)))
goto bad_area;
- if (!is_write)
+ if (unlikely(!is_write))
goto bad_area;
/*
@@ -179,7 +168,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
* before setting the user r1. Thus we allow the stack to
* expand to 1MB without further checks.
*/
- if (address + 0x100000 < vma->vm_end) {
+ if (unlikely(address + 0x100000 < vma->vm_end)) {
/* get user regs even if this fault is in kernel mode */
struct pt_regs *uregs = current->thread.regs;
@@ -209,15 +198,16 @@ good_area:
code = SEGV_ACCERR;
/* a write */
- if (is_write) {
- if (!(vma->vm_flags & VM_WRITE))
+ if (unlikely(is_write)) {
+ if (unlikely(!(vma->vm_flags & VM_WRITE)))
goto bad_area;
+ flags |= FAULT_FLAG_WRITE;
/* a read */
} else {
/* protection fault */
- if (error_code & 0x08000000)
+ if (unlikely(error_code & 0x08000000))
goto bad_area;
- if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
+ if (unlikely(!(vma->vm_flags & (VM_READ | VM_EXEC))))
goto bad_area;
}
@@ -226,8 +216,11 @@ good_area:
* make sure we exit gracefully rather than endlessly redo
* the fault.
*/
-survive:
- fault = handle_mm_fault(mm, vma, address, is_write ? FAULT_FLAG_WRITE : 0);
+ 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;
@@ -235,11 +228,28 @@ survive:
goto do_sigbus;
BUG();
}
- if (fault & VM_FAULT_MAJOR)
- current->maj_flt++;
- else
- current->min_flt++;
+
+ if (flags & FAULT_FLAG_ALLOW_RETRY) {
+ if (unlikely(fault & VM_FAULT_MAJOR))
+ current->maj_flt++;
+ else
+ current->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);
+
/*
* keep track of tlb+htab misses that are good addrs but
* just need pte's created via handle_mm_fault()
@@ -273,16 +283,11 @@ bad_area_nosemaphore:
* us unable to handle the page fault gracefully.
*/
out_of_memory:
- if (current->pid == 1) {
- yield();
- down_read(&mm->mmap_sem);
- goto survive;
- }
up_read(&mm->mmap_sem);
- printk(KERN_WARNING "VM: killing process %s\n", current->comm);
- if (user_mode(regs))
- do_exit(SIGKILL);
- bad_page_fault(regs, address, SIGKILL);
+ if (!user_mode(regs))
+ bad_page_fault(regs, address, SIGKILL);
+ else
+ pagefault_out_of_memory();
return;
do_sigbus:
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 07:14:16 +0000