[PATCH 15/47] Minor fixes to mm/fault.c for CRIS.

Jesper Nilsson
2007-12-06T12:46:57Z

- Only disallow oops if we're in_interrupt context (was in_atomic before)
- Use the generic oops_in_progress instead of the raw_printk hack.
- Fix whitespace/formatting.
- Remove CVS log entries.

Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
---
arch/cris/mm/fault.c | 169 ++++++++-----------------------------------------
1 files changed, 28 insertions(+), 141 deletions(-)

diff --git a/arch/cris/mm/fault.c b/arch/cris/mm/fault.c
index 3034f3f..c4c76db 100644
--- a/arch/cris/mm/fault.c
+++ b/arch/cris/mm/fault.c
@@ -1,130 +1,9 @@
/*
* linux/arch/cris/mm/fault.c
*
- * Copyright (C) 2000, 2001 Axis Communications AB
- *
- * Authors: Bjorn Wesen
- *
- * $Log: fault.c,v $
- * Revision 1.20 2005/03/04 08:16:18 starvik
- * Merge of Linux 2.6.11.
- *
- * Revision 1.19 2005/01/14 10:07:59 starvik
- * Fixed warning.
- *
- * Revision 1.18 2005/01/12 08:10:14 starvik
- * Re-added the change of frametype when handling kernel page fault fixup
- * for v10. This is necessary to avoid that the CPU remakes the faulting
- * access.
- *
- * Revision 1.17 2005/01/11 13:53:05 starvik
- * Use raw_printk.
- *
- * Revision 1.16 2004/12/17 11:39:41 starvik
- * SMP support.
- *
- * Revision 1.15 2004/11/23 18:36:18 starvik
- * Stack is now non-executable.
- * Signal handler trampolines are placed in a reserved page mapped into all
- * processes.
- *
- * Revision 1.14 2004/11/23 07:10:21 starvik
- * Moved find_fixup_code to generic code.
- *
- * Revision 1.13 2004/11/23 07:00:54 starvik
- * Actually use the execute permission bit in the MMU. This makes it possible
- * to prevent e.g. attacks where executable code is put on the stack.
- *
- * Revision 1.12 2004/09/29 06:16:04 starvik
- * Use instruction_pointer
- *
- * Revision 1.11 2004/05/14 07:58:05 starvik
- * Merge of changes from 2.4
- *
- * Revision 1.10 2003/10/27 14:51:24 starvik
- * Removed debugcode
- *
- * Revision 1.9 2003/10/27 14:50:42 starvik
- * Changed do_page_fault signature
- *
- * Revision 1.8 2003/07/04 13:02:48 tobiasa
- * Moved code snippet from arch/cris/mm/fault.c that searches for fixup code
- * to separate function in arch-specific files.
- *
- * Revision 1.7 2003/01/22 06:48:38 starvik
- * Fixed warnings issued by GCC 3.2.1
- *
- * Revision 1.6 2003/01/09 14:42:52 starvik
- * Merge of Linux 2.5.55
- *
- * Revision 1.5 2002/12/11 14:44:48 starvik
- * Extracted v10 (ETRAX 100LX) specific stuff to arch/cris/arch-v10/mm
- *
- * Revision 1.4 2002/11/13 15:10:28 starvik
- * pte_offset has been renamed to pte_offset_kernel
- *
- * Revision 1.3 2002/11/05 06:45:13 starvik
- * Merge of Linux 2.5.45
- *
- * Revision 1.2 2001/12/18 13:35:22 bjornw
- * Applied the 2.4.13->2.4.16 CRIS patch to 2.5.1 (is a copy of 2.4.15).
- *
- * Revision 1.20 2001/11/22 13:34:06 bjornw
- * * Bug workaround (LX TR89): force a rerun of the whole of an interrupted
- * unaligned write, because the second half of the write will be corrupted
- * otherwise. Affected unaligned writes spanning not-yet mapped pages.
- * * Optimization: use the wr_rd bit in R_MMU_CAUSE to know whether a miss
- * was due to a read or a write (before we didn't know this until the next
- * restart of the interrupted instruction, thus wasting one fault-irq)
- *
- * Revision 1.19 2001/11/12 19:02:10 pkj
- * Fixed compiler warnings.
- *
- * Revision 1.18 2001/07/18 22:14:32 bjornw
- * Enable interrupts in the bulk of do_page_fault
- *
- * Revision 1.17 2001/07/18 13:07:23 bjornw
- * * Detect non-existant PTE's in vmalloc pmd synchronization
- * * Remove comment about fast-paths for VMALLOC_START etc, because all that
- * was totally bogus anyway it turned out :)
- * * Fix detection of vmalloc-area synchronization
- * * Add some comments
- *
- * Revision 1.16 2001/06/13 00:06:08 bjornw
- * current_pgd should be volatile
- *
- * Revision 1.15 2001/06/13 00:02:23 bjornw
- * Use a separate variable to store the current pgd to avoid races in schedule
- *
- * Revision 1.14 2001/05/16 17:41:07 hp
- * Last comment tweak further tweaked.
- *
- * Revision 1.13 2001/05/15 00:58:44 hp
- * Expand a bit on the comment why we compare address >= TASK_SIZE rather
- * than >= VMALLOC_START.
- *
- * Revision 1.12 2001/04/04 10:51:14 bjornw
- * mmap_sem is grabbed for reading
- *
- * Revision 1.11 2001/03/23 07:36:07 starvik
- * Corrected according to review remarks
- *
- * Revision 1.10 2001/03/21 16:10:11 bjornw
- * CRIS_FRAME_FIXUP not needed anymore, use FRAME_NORMAL
- *
- * Revision 1.9 2001/03/05 13:22:20 bjornw
- * Spell-fix and fix in vmalloc_fault handling
- *
- * Revision 1.8 2000/11/22 14:45:31 bjornw
- * * 2.4.0-test10 removed the set_pgdir instantaneous kernel global mapping
- * into all processes. Instead we fill in the missing PTE entries on demand.
- *
- * Revision 1.7 2000/11/21 16:39:09 bjornw
- * fixup switches frametype
- *
- * Revision 1.6 2000/11/17 16:54:08 bjornw
- * More detailed siginfo reporting
+ * Copyright (C) 2000-2006 Axis Communications AB
*
+ * Authors: Bjorn Wesen
*
*/

@@ -135,7 +14,6 @@

extern int find_fixup_code(struct pt_regs *);
extern void die_if_kernel(const char *, struct pt_regs *, long);
-extern int raw_printk(const char *fmt, ...);

/* debug of low-level TLB reload */
#undef DEBUG
@@ -164,8 +42,8 @@ unsigned long cris_signal_return_page;
* address.
*
* error_code:
- * bit 0 == 0 means no page found, 1 means protection fault
- * bit 1 == 0 means read, 1 means write
+ * bit 0 == 0 means no page found, 1 means protection fault
+ * bit 1 == 0 means read, 1 means write
*
* If this routine detects a bad access, it returns 1, otherwise it
* returns 0.
@@ -181,9 +59,10 @@ do_page_fault(unsigned long address, struct pt_regs *regs,
siginfo_t info;
int fault;

- D(printk("Page fault for %lX on %X at %lX, prot %d write %d\n",
- address, smp_processor_id(), instruction_pointer(regs),
- protection, writeaccess));
+ D(printk(KERN_DEBUG
+ "Page fault for %lX on %X at %lX, prot %d write %d\n",
+ address, smp_processor_id(), instruction_pointer(regs),
+ protection, writeaccess));

tsk = current;

@@ -233,7 +112,7 @@ do_page_fault(unsigned long address, struct pt_regs *regs,
* context, we must not take the fault..
*/

- if (in_atomic() || !mm)
+ if (in_interrupt() || !mm)
goto no_context;

down_read(&mm->mmap_sem);
@@ -319,6 +198,9 @@ do_page_fault(unsigned long address, struct pt_regs *regs,
/* info.si_code has been set above */
info.si_addr = (void *)address;
force_sig_info(SIGSEGV, &info, tsk);
+ printk(KERN_NOTICE "%s (pid %d) segfaults for page "
+ "address %08lx at pc %08lx\n",
+ tsk->comm, tsk->pid, address, instruction_pointer(regs));
return;
}

@@ -326,7 +208,7 @@ do_page_fault(unsigned long address, struct pt_regs *regs,

/* Are we prepared to handle this kernel fault?
*
- * (The kernel has valid exception-points in the source
+ * (The kernel has valid exception-points in the source
* when it acesses user-memory. When it fails in one
* of those points, we find it in a table and do a jump
* to some fixup code that loads an appropriate error
@@ -341,13 +223,18 @@ do_page_fault(unsigned long address, struct pt_regs *regs,
* terminate things with extreme prejudice.
*/

- if ((unsigned long) (address) < PAGE_SIZE)
- raw_printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");
- else
- raw_printk(KERN_ALERT "Unable to handle kernel access");
- raw_printk(" at virtual address %08lx\n",address);
-
- die_if_kernel("Oops", regs, (writeaccess << 1) | protection);
+ if (!oops_in_progress) {
+ oops_in_progress = 1;
+ if ((unsigned long) (address) < PAGE_SIZE)
+ printk(KERN_ALERT "Unable to handle kernel NULL "
+ "pointer dereference");
+ else
+ printk(KERN_ALERT "Unable to handle kernel access"
+ " at virtual address %08lx\n", address);
+
+ die_if_kernel("Oops", regs, (writeaccess << 1) | protection);
+ oops_in_progress = 0;
+ }

do_exit(SIGKILL);

@@ -360,7 +247,7 @@ do_page_fault(unsigned long address, struct pt_regs *regs,
up_read(&mm->mmap_sem);
printk("VM: killing process %s\n", tsk->comm);
if (user_mode(regs))
- do_group_exit(SIGKILL);
+ do_exit(SIGKILL);
goto no_context;

do_sigbus:
@@ -406,8 +293,8 @@ vmalloc_fault:
/* Since we're two-level, we don't need to do both
* set_pgd and set_pmd (they do the same thing). If
* we go three-level at some point, do the right thing
- * with pgd_present and set_pgd here.
- *
+ * with pgd_present and set_pgd here.
+ *
* Also, since the vmalloc area is global, we don't
* need to copy individual PTE's, it is enough to
* copy the pgd pointer into the pte page of the
--
1.5.3.6.970.gd25430