2005-09-26 14:04:21 +08:00
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/*
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* PowerPC version
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* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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*
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* Derived from "arch/i386/mm/fault.c"
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
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*
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* Modified by Cort Dougan and Paul Mackerras.
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*
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* Modified for PPC64 by Dave Engebretsen (engebret@ibm.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/signal.h>
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#include <linux/sched.h>
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2017-02-09 01:51:37 +08:00
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#include <linux/sched/task_stack.h>
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2005-09-26 14:04:21 +08:00
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/ptrace.h>
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#include <linux/mman.h>
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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#include <linux/highmem.h>
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2016-08-16 22:57:34 +08:00
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#include <linux/extable.h>
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2005-09-26 14:04:21 +08:00
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#include <linux/kprobes.h>
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2007-05-08 15:27:03 +08:00
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#include <linux/kdebug.h>
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perf: Do the big rename: Performance Counters -> Performance Events
Bye-bye Performance Counters, welcome Performance Events!
In the past few months the perfcounters subsystem has grown out its
initial role of counting hardware events, and has become (and is
becoming) a much broader generic event enumeration, reporting, logging,
monitoring, analysis facility.
Naming its core object 'perf_counter' and naming the subsystem
'perfcounters' has become more and more of a misnomer. With pending
code like hw-breakpoints support the 'counter' name is less and
less appropriate.
All in one, we've decided to rename the subsystem to 'performance
events' and to propagate this rename through all fields, variables
and API names. (in an ABI compatible fashion)
The word 'event' is also a bit shorter than 'counter' - which makes
it slightly more convenient to write/handle as well.
Thanks goes to Stephane Eranian who first observed this misnomer and
suggested a rename.
User-space tooling and ABI compatibility is not affected - this patch
should be function-invariant. (Also, defconfigs were not touched to
keep the size down.)
This patch has been generated via the following script:
FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')
sed -i \
-e 's/PERF_EVENT_/PERF_RECORD_/g' \
-e 's/PERF_COUNTER/PERF_EVENT/g' \
-e 's/perf_counter/perf_event/g' \
-e 's/nb_counters/nb_events/g' \
-e 's/swcounter/swevent/g' \
-e 's/tpcounter_event/tp_event/g' \
$FILES
for N in $(find . -name perf_counter.[ch]); do
M=$(echo $N | sed 's/perf_counter/perf_event/g')
mv $N $M
done
FILES=$(find . -name perf_event.*)
sed -i \
-e 's/COUNTER_MASK/REG_MASK/g' \
-e 's/COUNTER/EVENT/g' \
-e 's/\<event\>/event_id/g' \
-e 's/counter/event/g' \
-e 's/Counter/Event/g' \
$FILES
... to keep it as correct as possible. This script can also be
used by anyone who has pending perfcounters patches - it converts
a Linux kernel tree over to the new naming. We tried to time this
change to the point in time where the amount of pending patches
is the smallest: the end of the merge window.
Namespace clashes were fixed up in a preparatory patch - and some
stylistic fallout will be fixed up in a subsequent patch.
( NOTE: 'counters' are still the proper terminology when we deal
with hardware registers - and these sed scripts are a bit
over-eager in renaming them. I've undone some of that, but
in case there's something left where 'counter' would be
better than 'event' we can undo that on an individual basis
instead of touching an otherwise nicely automated patch. )
Suggested-by: Stephane Eranian <eranian@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Reviewed-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 18:02:48 +08:00
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#include <linux/perf_event.h>
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2011-06-04 13:36:54 +08:00
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#include <linux/ratelimit.h>
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powerpc: Exception hooks for context tracking subsystem
This is the exception hooks for context tracking subsystem, including
data access, program check, single step, instruction breakpoint, machine check,
alignment, fp unavailable, altivec assist, unknown exception, whose handlers
might use RCU.
This patch corresponds to
[PATCH] x86: Exception hooks for userspace RCU extended QS
commit 6ba3c97a38803883c2eee489505796cb0a727122
But after the exception handling moved to generic code, and some changes in
following two commits:
56dd9470d7c8734f055da2a6bac553caf4a468eb
context_tracking: Move exception handling to generic code
6c1e0256fad84a843d915414e4b5973b7443d48d
context_tracking: Restore correct previous context state on exception exit
it is able for exception hooks to use the generic code above instead of a
redundant arch implementation.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 00:16:41 +08:00
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#include <linux/context_tracking.h>
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2014-09-24 14:59:58 +08:00
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#include <linux/hugetlb.h>
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2015-05-11 23:52:11 +08:00
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#include <linux/uaccess.h>
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2005-09-26 14:04:21 +08:00
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2008-10-22 13:53:45 +08:00
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#include <asm/firmware.h>
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2005-09-26 14:04:21 +08:00
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/mmu.h>
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#include <asm/mmu_context.h>
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#include <asm/tlbflush.h>
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#include <asm/siginfo.h>
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2012-03-29 01:30:02 +08:00
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#include <asm/debug.h>
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2006-06-26 15:25:27 +08:00
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2011-09-29 18:55:14 +08:00
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#include "icswx.h"
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2007-04-30 18:56:46 +08:00
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#ifdef CONFIG_KPROBES
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static inline int notify_page_fault(struct pt_regs *regs)
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2006-06-26 15:25:27 +08:00
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{
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2007-04-30 18:56:46 +08:00
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int ret = 0;
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/* kprobe_running() needs smp_processor_id() */
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if (!user_mode(regs)) {
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preempt_disable();
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if (kprobe_running() && kprobe_fault_handler(regs, 11))
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ret = 1;
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preempt_enable();
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}
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2006-06-26 15:25:27 +08:00
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2007-04-30 18:56:46 +08:00
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return ret;
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2006-06-26 15:25:27 +08:00
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}
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#else
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2007-04-30 18:56:46 +08:00
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static inline int notify_page_fault(struct pt_regs *regs)
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2006-06-26 15:25:27 +08:00
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{
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2007-04-30 18:56:46 +08:00
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return 0;
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2006-06-26 15:25:27 +08:00
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}
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#endif
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2005-09-26 14:04:21 +08:00
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/*
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* Check whether the instruction at regs->nip is a store using
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* an update addressing form which will update r1.
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*/
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static int store_updates_sp(struct pt_regs *regs)
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{
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unsigned int inst;
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if (get_user(inst, (unsigned int __user *)regs->nip))
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return 0;
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/* check for 1 in the rA field */
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if (((inst >> 16) & 0x1f) != 1)
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return 0;
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/* check major opcode */
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switch (inst >> 26) {
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case 37: /* stwu */
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case 39: /* stbu */
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case 45: /* sthu */
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case 53: /* stfsu */
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case 55: /* stfdu */
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return 1;
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case 62: /* std or stdu */
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return (inst & 3) == 1;
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case 31:
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/* check minor opcode */
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switch ((inst >> 1) & 0x3ff) {
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case 181: /* stdux */
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case 183: /* stwux */
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case 247: /* stbux */
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case 439: /* sthux */
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case 695: /* stfsux */
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case 759: /* stfdux */
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return 1;
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}
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}
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return 0;
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}
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2012-03-01 15:14:45 +08:00
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/*
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* do_page_fault error handling helpers
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*/
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#define MM_FAULT_RETURN 0
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#define MM_FAULT_CONTINUE -1
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#define MM_FAULT_ERR(sig) (sig)
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|
2014-09-24 14:59:57 +08:00
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static int do_sigbus(struct pt_regs *regs, unsigned long address,
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unsigned int fault)
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2012-03-01 15:14:45 +08:00
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{
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siginfo_t info;
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2014-09-24 14:59:58 +08:00
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unsigned int lsb = 0;
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2012-03-01 15:14:45 +08:00
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2014-09-24 14:59:56 +08:00
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if (!user_mode(regs))
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return MM_FAULT_ERR(SIGBUS);
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current->thread.trap_nr = BUS_ADRERR;
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info.si_signo = SIGBUS;
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info.si_errno = 0;
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info.si_code = BUS_ADRERR;
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info.si_addr = (void __user *)address;
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2014-09-24 14:59:57 +08:00
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#ifdef CONFIG_MEMORY_FAILURE
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if (fault & (VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE)) {
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pr_err("MCE: Killing %s:%d due to hardware memory corruption fault at %lx\n",
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current->comm, current->pid, address);
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info.si_code = BUS_MCEERR_AR;
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}
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2014-09-24 14:59:58 +08:00
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if (fault & VM_FAULT_HWPOISON_LARGE)
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lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));
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if (fault & VM_FAULT_HWPOISON)
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lsb = PAGE_SHIFT;
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2014-09-24 14:59:57 +08:00
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#endif
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2014-09-24 14:59:58 +08:00
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info.si_addr_lsb = lsb;
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2014-09-24 14:59:56 +08:00
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force_sig_info(SIGBUS, &info, current);
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return MM_FAULT_RETURN;
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2012-03-01 15:14:45 +08:00
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}
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static int mm_fault_error(struct pt_regs *regs, unsigned long addr, int fault)
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{
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/*
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* Pagefault was interrupted by SIGKILL. We have no reason to
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* continue the pagefault.
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*/
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if (fatal_signal_pending(current)) {
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/* Coming from kernel, we need to deal with uaccess fixups */
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if (user_mode(regs))
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return MM_FAULT_RETURN;
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return MM_FAULT_ERR(SIGKILL);
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}
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/* No fault: be happy */
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if (!(fault & VM_FAULT_ERROR))
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return MM_FAULT_CONTINUE;
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/* Out of memory */
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2012-12-13 05:52:10 +08:00
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if (fault & VM_FAULT_OOM) {
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/*
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* We ran out of memory, or some other thing happened to us that
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* made us unable to handle the page fault gracefully.
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*/
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if (!user_mode(regs))
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return MM_FAULT_ERR(SIGKILL);
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pagefault_out_of_memory();
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return MM_FAULT_RETURN;
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}
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2012-03-01 15:14:45 +08:00
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2017-02-15 00:45:12 +08:00
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if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE))
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2014-09-24 14:59:57 +08:00
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return do_sigbus(regs, addr, fault);
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2012-03-01 15:14:45 +08:00
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/* We don't understand the fault code, this is fatal */
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BUG();
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return MM_FAULT_CONTINUE;
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}
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2005-09-26 14:04:21 +08:00
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/*
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* For 600- and 800-family processors, the error_code parameter is DSISR
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* for a data fault, SRR1 for an instruction fault. For 400-family processors
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* the error_code parameter is ESR for a data fault, 0 for an instruction
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* fault.
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* For 64-bit processors, the error_code parameter is
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* - DSISR for a non-SLB data access fault,
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* - SRR1 & 0x08000000 for a non-SLB instruction access fault
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* - 0 any SLB fault.
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*
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* The return value is 0 if the fault was handled, or the signal
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* number if this is a kernel fault that can't be handled here.
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*/
|
2016-09-16 18:48:08 +08:00
|
|
|
int do_page_fault(struct pt_regs *regs, unsigned long address,
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2005-09-26 14:04:21 +08:00
|
|
|
unsigned long error_code)
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|
|
|
|
{
|
powerpc: Exception hooks for context tracking subsystem
This is the exception hooks for context tracking subsystem, including
data access, program check, single step, instruction breakpoint, machine check,
alignment, fp unavailable, altivec assist, unknown exception, whose handlers
might use RCU.
This patch corresponds to
[PATCH] x86: Exception hooks for userspace RCU extended QS
commit 6ba3c97a38803883c2eee489505796cb0a727122
But after the exception handling moved to generic code, and some changes in
following two commits:
56dd9470d7c8734f055da2a6bac553caf4a468eb
context_tracking: Move exception handling to generic code
6c1e0256fad84a843d915414e4b5973b7443d48d
context_tracking: Restore correct previous context state on exception exit
it is able for exception hooks to use the generic code above instead of a
redundant arch implementation.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 00:16:41 +08:00
|
|
|
enum ctx_state prev_state = exception_enter();
|
2005-09-26 14:04:21 +08:00
|
|
|
struct vm_area_struct * vma;
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|
struct mm_struct *mm = current->mm;
|
2012-03-01 15:14:45 +08:00
|
|
|
unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
|
2005-09-26 14:04:21 +08:00
|
|
|
int code = SEGV_MAPERR;
|
2012-03-01 15:14:45 +08:00
|
|
|
int is_write = 0;
|
2005-09-26 14:04:21 +08:00
|
|
|
int trap = TRAP(regs);
|
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|
|
int is_exec = trap == 0x400;
|
powerpc/mm: Evaluate user_mode(regs) only once in do_page_fault()
Analysis of the assembly code shows that when using user_mode(regs),
at least the 'andi.' is redone all the time, and also
the 'lwz ,132(r31)' most of the time. With the new form, the 'is_user'
is mapped to cr4, then all further use of is_user results in just
things like 'beq cr4,218 <do_page_fault+0x218>'
Without the patch:
50: 81 1e 00 84 lwz r8,132(r30)
54: 71 09 40 00 andi. r9,r8,16384
58: 40 82 00 0c bne 64 <do_page_fault+0x64>
84: 81 3e 00 84 lwz r9,132(r30)
8c: 71 2a 40 00 andi. r10,r9,16384
90: 41 a2 01 64 beq 1f4 <do_page_fault+0x1f4>
d4: 81 3e 00 84 lwz r9,132(r30)
dc: 71 28 40 00 andi. r8,r9,16384
e0: 41 82 02 08 beq 2e8 <do_page_fault+0x2e8>
108: 81 3e 00 84 lwz r9,132(r30)
110: 71 28 40 00 andi. r8,r9,16384
118: 41 82 02 28 beq 340 <do_page_fault+0x340>
1e4: 81 3e 00 84 lwz r9,132(r30)
1e8: 71 2a 40 00 andi. r10,r9,16384
1ec: 40 82 01 68 bne 354 <do_page_fault+0x354>
228: 81 3e 00 84 lwz r9,132(r30)
22c: 71 28 40 00 andi. r8,r9,16384
230: 41 82 ff c4 beq 1f4 <do_page_fault+0x1f4>
288: 71 2a 40 00 andi. r10,r9,16384
294: 41 a2 fe 60 beq f4 <do_page_fault+0xf4>
50c: 81 3e 00 84 lwz r9,132(r30)
514: 71 2a 40 00 andi. r10,r9,16384
518: 40 a2 fc e0 bne 1f8 <do_page_fault+0x1f8>
534: 81 3e 00 84 lwz r9,132(r30)
53c: 71 2a 40 00 andi. r10,r9,16384
540: 41 82 fc b8 beq 1f8 <do_page_fault+0x1f8>
This patch creates a local var called 'is_user' which contains the
result of user_mode(regs)
With the patch:
20: 81 03 00 84 lwz r8,132(r3)
48: 55 09 97 fe rlwinm r9,r8,18,31,31
58: 2e 09 00 00 cmpwi cr4,r9,0
5c: 40 92 00 0c bne cr4,68 <do_page_fault+0x68>
88: 41 b2 01 90 beq cr4,218 <do_page_fault+0x218>
d4: 40 92 01 d0 bne cr4,2a4 <do_page_fault+0x2a4>
120: 41 b2 00 f8 beq cr4,218 <do_page_fault+0x218>
138: 41 b2 ff a0 beq cr4,d8 <do_page_fault+0xd8>
1d4: 40 92 00 e0 bne cr4,2b4 <do_page_fault+0x2b4>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-19 20:56:30 +08:00
|
|
|
int is_user = user_mode(regs);
|
2012-03-01 15:14:45 +08:00
|
|
|
int fault;
|
2013-09-10 21:14:42 +08:00
|
|
|
int rc = 0, store_update_sp = 0;
|
2005-09-26 14:04:21 +08:00
|
|
|
|
|
|
|
|
#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
|
|
|
|
|
/*
|
|
|
|
|
* Fortunately the bit assignments in SRR1 for an instruction
|
|
|
|
|
* fault and DSISR for a data fault are mostly the same for the
|
|
|
|
|
* bits we are interested in. But there are some bits which
|
|
|
|
|
* indicate errors in DSISR but can validly be set in SRR1.
|
|
|
|
|
*/
|
2017-04-19 20:56:28 +08:00
|
|
|
if (is_exec)
|
2005-09-26 14:04:21 +08:00
|
|
|
error_code &= 0x48200000;
|
|
|
|
|
else
|
|
|
|
|
is_write = error_code & DSISR_ISSTORE;
|
|
|
|
|
#else
|
|
|
|
|
is_write = error_code & ESR_DST;
|
|
|
|
|
#endif /* CONFIG_4xx || CONFIG_BOOKE */
|
|
|
|
|
|
2011-09-29 18:55:14 +08:00
|
|
|
#ifdef CONFIG_PPC_ICSWX
|
|
|
|
|
/*
|
|
|
|
|
* we need to do this early because this "data storage
|
|
|
|
|
* interrupt" does not update the DAR/DEAR so we don't want to
|
|
|
|
|
* look at it
|
|
|
|
|
*/
|
|
|
|
|
if (error_code & ICSWX_DSI_UCT) {
|
powerpc: Exception hooks for context tracking subsystem
This is the exception hooks for context tracking subsystem, including
data access, program check, single step, instruction breakpoint, machine check,
alignment, fp unavailable, altivec assist, unknown exception, whose handlers
might use RCU.
This patch corresponds to
[PATCH] x86: Exception hooks for userspace RCU extended QS
commit 6ba3c97a38803883c2eee489505796cb0a727122
But after the exception handling moved to generic code, and some changes in
following two commits:
56dd9470d7c8734f055da2a6bac553caf4a468eb
context_tracking: Move exception handling to generic code
6c1e0256fad84a843d915414e4b5973b7443d48d
context_tracking: Restore correct previous context state on exception exit
it is able for exception hooks to use the generic code above instead of a
redundant arch implementation.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 00:16:41 +08:00
|
|
|
rc = acop_handle_fault(regs, address, error_code);
|
2012-03-01 15:14:45 +08:00
|
|
|
if (rc)
|
powerpc: Exception hooks for context tracking subsystem
This is the exception hooks for context tracking subsystem, including
data access, program check, single step, instruction breakpoint, machine check,
alignment, fp unavailable, altivec assist, unknown exception, whose handlers
might use RCU.
This patch corresponds to
[PATCH] x86: Exception hooks for userspace RCU extended QS
commit 6ba3c97a38803883c2eee489505796cb0a727122
But after the exception handling moved to generic code, and some changes in
following two commits:
56dd9470d7c8734f055da2a6bac553caf4a468eb
context_tracking: Move exception handling to generic code
6c1e0256fad84a843d915414e4b5973b7443d48d
context_tracking: Restore correct previous context state on exception exit
it is able for exception hooks to use the generic code above instead of a
redundant arch implementation.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 00:16:41 +08:00
|
|
|
goto bail;
|
2011-09-29 18:55:14 +08:00
|
|
|
}
|
2012-03-01 15:14:45 +08:00
|
|
|
#endif /* CONFIG_PPC_ICSWX */
|
2011-09-29 18:55:14 +08:00
|
|
|
|
2007-04-30 18:56:46 +08:00
|
|
|
if (notify_page_fault(regs))
|
powerpc: Exception hooks for context tracking subsystem
This is the exception hooks for context tracking subsystem, including
data access, program check, single step, instruction breakpoint, machine check,
alignment, fp unavailable, altivec assist, unknown exception, whose handlers
might use RCU.
This patch corresponds to
[PATCH] x86: Exception hooks for userspace RCU extended QS
commit 6ba3c97a38803883c2eee489505796cb0a727122
But after the exception handling moved to generic code, and some changes in
following two commits:
56dd9470d7c8734f055da2a6bac553caf4a468eb
context_tracking: Move exception handling to generic code
6c1e0256fad84a843d915414e4b5973b7443d48d
context_tracking: Restore correct previous context state on exception exit
it is able for exception hooks to use the generic code above instead of a
redundant arch implementation.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 00:16:41 +08:00
|
|
|
goto bail;
|
2005-09-26 14:04:21 +08:00
|
|
|
|
2008-01-18 12:50:30 +08:00
|
|
|
if (unlikely(debugger_fault_handler(regs)))
|
powerpc: Exception hooks for context tracking subsystem
This is the exception hooks for context tracking subsystem, including
data access, program check, single step, instruction breakpoint, machine check,
alignment, fp unavailable, altivec assist, unknown exception, whose handlers
might use RCU.
This patch corresponds to
[PATCH] x86: Exception hooks for userspace RCU extended QS
commit 6ba3c97a38803883c2eee489505796cb0a727122
But after the exception handling moved to generic code, and some changes in
following two commits:
56dd9470d7c8734f055da2a6bac553caf4a468eb
context_tracking: Move exception handling to generic code
6c1e0256fad84a843d915414e4b5973b7443d48d
context_tracking: Restore correct previous context state on exception exit
it is able for exception hooks to use the generic code above instead of a
redundant arch implementation.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 00:16:41 +08:00
|
|
|
goto bail;
|
2005-09-26 14:04:21 +08:00
|
|
|
|
2017-02-03 14:10:28 +08:00
|
|
|
/*
|
|
|
|
|
* The kernel should never take an execute fault nor should it
|
|
|
|
|
* take a page fault to a kernel address.
|
|
|
|
|
*/
|
powerpc/mm: Evaluate user_mode(regs) only once in do_page_fault()
Analysis of the assembly code shows that when using user_mode(regs),
at least the 'andi.' is redone all the time, and also
the 'lwz ,132(r31)' most of the time. With the new form, the 'is_user'
is mapped to cr4, then all further use of is_user results in just
things like 'beq cr4,218 <do_page_fault+0x218>'
Without the patch:
50: 81 1e 00 84 lwz r8,132(r30)
54: 71 09 40 00 andi. r9,r8,16384
58: 40 82 00 0c bne 64 <do_page_fault+0x64>
84: 81 3e 00 84 lwz r9,132(r30)
8c: 71 2a 40 00 andi. r10,r9,16384
90: 41 a2 01 64 beq 1f4 <do_page_fault+0x1f4>
d4: 81 3e 00 84 lwz r9,132(r30)
dc: 71 28 40 00 andi. r8,r9,16384
e0: 41 82 02 08 beq 2e8 <do_page_fault+0x2e8>
108: 81 3e 00 84 lwz r9,132(r30)
110: 71 28 40 00 andi. r8,r9,16384
118: 41 82 02 28 beq 340 <do_page_fault+0x340>
1e4: 81 3e 00 84 lwz r9,132(r30)
1e8: 71 2a 40 00 andi. r10,r9,16384
1ec: 40 82 01 68 bne 354 <do_page_fault+0x354>
228: 81 3e 00 84 lwz r9,132(r30)
22c: 71 28 40 00 andi. r8,r9,16384
230: 41 82 ff c4 beq 1f4 <do_page_fault+0x1f4>
288: 71 2a 40 00 andi. r10,r9,16384
294: 41 a2 fe 60 beq f4 <do_page_fault+0xf4>
50c: 81 3e 00 84 lwz r9,132(r30)
514: 71 2a 40 00 andi. r10,r9,16384
518: 40 a2 fc e0 bne 1f8 <do_page_fault+0x1f8>
534: 81 3e 00 84 lwz r9,132(r30)
53c: 71 2a 40 00 andi. r10,r9,16384
540: 41 82 fc b8 beq 1f8 <do_page_fault+0x1f8>
This patch creates a local var called 'is_user' which contains the
result of user_mode(regs)
With the patch:
20: 81 03 00 84 lwz r8,132(r3)
48: 55 09 97 fe rlwinm r9,r8,18,31,31
58: 2e 09 00 00 cmpwi cr4,r9,0
5c: 40 92 00 0c bne cr4,68 <do_page_fault+0x68>
88: 41 b2 01 90 beq cr4,218 <do_page_fault+0x218>
d4: 40 92 01 d0 bne cr4,2a4 <do_page_fault+0x2a4>
120: 41 b2 00 f8 beq cr4,218 <do_page_fault+0x218>
138: 41 b2 ff a0 beq cr4,d8 <do_page_fault+0xd8>
1d4: 40 92 00 e0 bne cr4,2b4 <do_page_fault+0x2b4>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-19 20:56:30 +08:00
|
|
|
if (!is_user && (is_exec || (address >= TASK_SIZE))) {
|
powerpc: Exception hooks for context tracking subsystem
This is the exception hooks for context tracking subsystem, including
data access, program check, single step, instruction breakpoint, machine check,
alignment, fp unavailable, altivec assist, unknown exception, whose handlers
might use RCU.
This patch corresponds to
[PATCH] x86: Exception hooks for userspace RCU extended QS
commit 6ba3c97a38803883c2eee489505796cb0a727122
But after the exception handling moved to generic code, and some changes in
following two commits:
56dd9470d7c8734f055da2a6bac553caf4a468eb
context_tracking: Move exception handling to generic code
6c1e0256fad84a843d915414e4b5973b7443d48d
context_tracking: Restore correct previous context state on exception exit
it is able for exception hooks to use the generic code above instead of a
redundant arch implementation.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 00:16:41 +08:00
|
|
|
rc = SIGSEGV;
|
|
|
|
|
goto bail;
|
|
|
|
|
}
|
2005-09-26 14:04:21 +08:00
|
|
|
|
2010-03-30 07:59:25 +08:00
|
|
|
#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE) || \
|
2017-04-19 20:56:32 +08:00
|
|
|
defined(CONFIG_PPC_BOOK3S_64) || defined(CONFIG_PPC_8xx))
|
2005-09-26 14:04:21 +08:00
|
|
|
if (error_code & DSISR_DABRMATCH) {
|
2012-12-20 22:06:44 +08:00
|
|
|
/* breakpoint match */
|
|
|
|
|
do_break(regs, address, error_code);
|
powerpc: Exception hooks for context tracking subsystem
This is the exception hooks for context tracking subsystem, including
data access, program check, single step, instruction breakpoint, machine check,
alignment, fp unavailable, altivec assist, unknown exception, whose handlers
might use RCU.
This patch corresponds to
[PATCH] x86: Exception hooks for userspace RCU extended QS
commit 6ba3c97a38803883c2eee489505796cb0a727122
But after the exception handling moved to generic code, and some changes in
following two commits:
56dd9470d7c8734f055da2a6bac553caf4a468eb
context_tracking: Move exception handling to generic code
6c1e0256fad84a843d915414e4b5973b7443d48d
context_tracking: Restore correct previous context state on exception exit
it is able for exception hooks to use the generic code above instead of a
redundant arch implementation.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 00:16:41 +08:00
|
|
|
goto bail;
|
2005-09-26 14:04:21 +08:00
|
|
|
}
|
2010-03-30 07:59:25 +08:00
|
|
|
#endif
|
2005-09-26 14:04:21 +08:00
|
|
|
|
2012-03-07 13:48:45 +08:00
|
|
|
/* We restore the interrupt state now */
|
|
|
|
|
if (!arch_irq_disabled_regs(regs))
|
|
|
|
|
local_irq_enable();
|
|
|
|
|
|
2015-05-11 23:52:11 +08:00
|
|
|
if (faulthandler_disabled() || mm == NULL) {
|
powerpc/mm: Evaluate user_mode(regs) only once in do_page_fault()
Analysis of the assembly code shows that when using user_mode(regs),
at least the 'andi.' is redone all the time, and also
the 'lwz ,132(r31)' most of the time. With the new form, the 'is_user'
is mapped to cr4, then all further use of is_user results in just
things like 'beq cr4,218 <do_page_fault+0x218>'
Without the patch:
50: 81 1e 00 84 lwz r8,132(r30)
54: 71 09 40 00 andi. r9,r8,16384
58: 40 82 00 0c bne 64 <do_page_fault+0x64>
84: 81 3e 00 84 lwz r9,132(r30)
8c: 71 2a 40 00 andi. r10,r9,16384
90: 41 a2 01 64 beq 1f4 <do_page_fault+0x1f4>
d4: 81 3e 00 84 lwz r9,132(r30)
dc: 71 28 40 00 andi. r8,r9,16384
e0: 41 82 02 08 beq 2e8 <do_page_fault+0x2e8>
108: 81 3e 00 84 lwz r9,132(r30)
110: 71 28 40 00 andi. r8,r9,16384
118: 41 82 02 28 beq 340 <do_page_fault+0x340>
1e4: 81 3e 00 84 lwz r9,132(r30)
1e8: 71 2a 40 00 andi. r10,r9,16384
1ec: 40 82 01 68 bne 354 <do_page_fault+0x354>
228: 81 3e 00 84 lwz r9,132(r30)
22c: 71 28 40 00 andi. r8,r9,16384
230: 41 82 ff c4 beq 1f4 <do_page_fault+0x1f4>
288: 71 2a 40 00 andi. r10,r9,16384
294: 41 a2 fe 60 beq f4 <do_page_fault+0xf4>
50c: 81 3e 00 84 lwz r9,132(r30)
514: 71 2a 40 00 andi. r10,r9,16384
518: 40 a2 fc e0 bne 1f8 <do_page_fault+0x1f8>
534: 81 3e 00 84 lwz r9,132(r30)
53c: 71 2a 40 00 andi. r10,r9,16384
540: 41 82 fc b8 beq 1f8 <do_page_fault+0x1f8>
This patch creates a local var called 'is_user' which contains the
result of user_mode(regs)
With the patch:
20: 81 03 00 84 lwz r8,132(r3)
48: 55 09 97 fe rlwinm r9,r8,18,31,31
58: 2e 09 00 00 cmpwi cr4,r9,0
5c: 40 92 00 0c bne cr4,68 <do_page_fault+0x68>
88: 41 b2 01 90 beq cr4,218 <do_page_fault+0x218>
d4: 40 92 01 d0 bne cr4,2a4 <do_page_fault+0x2a4>
120: 41 b2 00 f8 beq cr4,218 <do_page_fault+0x218>
138: 41 b2 ff a0 beq cr4,d8 <do_page_fault+0xd8>
1d4: 40 92 00 e0 bne cr4,2b4 <do_page_fault+0x2b4>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-19 20:56:30 +08:00
|
|
|
if (!is_user) {
|
powerpc: Exception hooks for context tracking subsystem
This is the exception hooks for context tracking subsystem, including
data access, program check, single step, instruction breakpoint, machine check,
alignment, fp unavailable, altivec assist, unknown exception, whose handlers
might use RCU.
This patch corresponds to
[PATCH] x86: Exception hooks for userspace RCU extended QS
commit 6ba3c97a38803883c2eee489505796cb0a727122
But after the exception handling moved to generic code, and some changes in
following two commits:
56dd9470d7c8734f055da2a6bac553caf4a468eb
context_tracking: Move exception handling to generic code
6c1e0256fad84a843d915414e4b5973b7443d48d
context_tracking: Restore correct previous context state on exception exit
it is able for exception hooks to use the generic code above instead of a
redundant arch implementation.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 00:16:41 +08:00
|
|
|
rc = SIGSEGV;
|
|
|
|
|
goto bail;
|
|
|
|
|
}
|
2015-05-11 23:52:11 +08:00
|
|
|
/* faulthandler_disabled() in user mode is really bad,
|
2005-09-26 14:04:21 +08:00
|
|
|
as is current->mm == NULL. */
|
2007-11-20 09:47:55 +08:00
|
|
|
printk(KERN_EMERG "Page fault in user mode with "
|
2015-05-11 23:52:11 +08:00
|
|
|
"faulthandler_disabled() = %d mm = %p\n",
|
|
|
|
|
faulthandler_disabled(), mm);
|
2005-09-26 14:04:21 +08:00
|
|
|
printk(KERN_EMERG "NIP = %lx MSR = %lx\n",
|
|
|
|
|
regs->nip, regs->msr);
|
|
|
|
|
die("Weird page fault", regs, SIGSEGV);
|
|
|
|
|
}
|
|
|
|
|
|
2011-06-27 20:41:57 +08:00
|
|
|
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
|
2009-03-13 19:21:33 +08:00
|
|
|
|
2013-09-10 21:14:42 +08:00
|
|
|
/*
|
|
|
|
|
* We want to do this outside mmap_sem, because reading code around nip
|
|
|
|
|
* can result in fault, which will cause a deadlock when called with
|
|
|
|
|
* mmap_sem held
|
|
|
|
|
*/
|
powerpc/mm: Evaluate user_mode(regs) only once in do_page_fault()
Analysis of the assembly code shows that when using user_mode(regs),
at least the 'andi.' is redone all the time, and also
the 'lwz ,132(r31)' most of the time. With the new form, the 'is_user'
is mapped to cr4, then all further use of is_user results in just
things like 'beq cr4,218 <do_page_fault+0x218>'
Without the patch:
50: 81 1e 00 84 lwz r8,132(r30)
54: 71 09 40 00 andi. r9,r8,16384
58: 40 82 00 0c bne 64 <do_page_fault+0x64>
84: 81 3e 00 84 lwz r9,132(r30)
8c: 71 2a 40 00 andi. r10,r9,16384
90: 41 a2 01 64 beq 1f4 <do_page_fault+0x1f4>
d4: 81 3e 00 84 lwz r9,132(r30)
dc: 71 28 40 00 andi. r8,r9,16384
e0: 41 82 02 08 beq 2e8 <do_page_fault+0x2e8>
108: 81 3e 00 84 lwz r9,132(r30)
110: 71 28 40 00 andi. r8,r9,16384
118: 41 82 02 28 beq 340 <do_page_fault+0x340>
1e4: 81 3e 00 84 lwz r9,132(r30)
1e8: 71 2a 40 00 andi. r10,r9,16384
1ec: 40 82 01 68 bne 354 <do_page_fault+0x354>
228: 81 3e 00 84 lwz r9,132(r30)
22c: 71 28 40 00 andi. r8,r9,16384
230: 41 82 ff c4 beq 1f4 <do_page_fault+0x1f4>
288: 71 2a 40 00 andi. r10,r9,16384
294: 41 a2 fe 60 beq f4 <do_page_fault+0xf4>
50c: 81 3e 00 84 lwz r9,132(r30)
514: 71 2a 40 00 andi. r10,r9,16384
518: 40 a2 fc e0 bne 1f8 <do_page_fault+0x1f8>
534: 81 3e 00 84 lwz r9,132(r30)
53c: 71 2a 40 00 andi. r10,r9,16384
540: 41 82 fc b8 beq 1f8 <do_page_fault+0x1f8>
This patch creates a local var called 'is_user' which contains the
result of user_mode(regs)
With the patch:
20: 81 03 00 84 lwz r8,132(r3)
48: 55 09 97 fe rlwinm r9,r8,18,31,31
58: 2e 09 00 00 cmpwi cr4,r9,0
5c: 40 92 00 0c bne cr4,68 <do_page_fault+0x68>
88: 41 b2 01 90 beq cr4,218 <do_page_fault+0x218>
d4: 40 92 01 d0 bne cr4,2a4 <do_page_fault+0x2a4>
120: 41 b2 00 f8 beq cr4,218 <do_page_fault+0x218>
138: 41 b2 ff a0 beq cr4,d8 <do_page_fault+0xd8>
1d4: 40 92 00 e0 bne cr4,2b4 <do_page_fault+0x2b4>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-19 20:56:30 +08:00
|
|
|
if (is_write && is_user)
|
2013-09-10 21:14:42 +08:00
|
|
|
store_update_sp = store_updates_sp(regs);
|
|
|
|
|
|
powerpc/mm: Evaluate user_mode(regs) only once in do_page_fault()
Analysis of the assembly code shows that when using user_mode(regs),
at least the 'andi.' is redone all the time, and also
the 'lwz ,132(r31)' most of the time. With the new form, the 'is_user'
is mapped to cr4, then all further use of is_user results in just
things like 'beq cr4,218 <do_page_fault+0x218>'
Without the patch:
50: 81 1e 00 84 lwz r8,132(r30)
54: 71 09 40 00 andi. r9,r8,16384
58: 40 82 00 0c bne 64 <do_page_fault+0x64>
84: 81 3e 00 84 lwz r9,132(r30)
8c: 71 2a 40 00 andi. r10,r9,16384
90: 41 a2 01 64 beq 1f4 <do_page_fault+0x1f4>
d4: 81 3e 00 84 lwz r9,132(r30)
dc: 71 28 40 00 andi. r8,r9,16384
e0: 41 82 02 08 beq 2e8 <do_page_fault+0x2e8>
108: 81 3e 00 84 lwz r9,132(r30)
110: 71 28 40 00 andi. r8,r9,16384
118: 41 82 02 28 beq 340 <do_page_fault+0x340>
1e4: 81 3e 00 84 lwz r9,132(r30)
1e8: 71 2a 40 00 andi. r10,r9,16384
1ec: 40 82 01 68 bne 354 <do_page_fault+0x354>
228: 81 3e 00 84 lwz r9,132(r30)
22c: 71 28 40 00 andi. r8,r9,16384
230: 41 82 ff c4 beq 1f4 <do_page_fault+0x1f4>
288: 71 2a 40 00 andi. r10,r9,16384
294: 41 a2 fe 60 beq f4 <do_page_fault+0xf4>
50c: 81 3e 00 84 lwz r9,132(r30)
514: 71 2a 40 00 andi. r10,r9,16384
518: 40 a2 fc e0 bne 1f8 <do_page_fault+0x1f8>
534: 81 3e 00 84 lwz r9,132(r30)
53c: 71 2a 40 00 andi. r10,r9,16384
540: 41 82 fc b8 beq 1f8 <do_page_fault+0x1f8>
This patch creates a local var called 'is_user' which contains the
result of user_mode(regs)
With the patch:
20: 81 03 00 84 lwz r8,132(r3)
48: 55 09 97 fe rlwinm r9,r8,18,31,31
58: 2e 09 00 00 cmpwi cr4,r9,0
5c: 40 92 00 0c bne cr4,68 <do_page_fault+0x68>
88: 41 b2 01 90 beq cr4,218 <do_page_fault+0x218>
d4: 40 92 01 d0 bne cr4,2a4 <do_page_fault+0x2a4>
120: 41 b2 00 f8 beq cr4,218 <do_page_fault+0x218>
138: 41 b2 ff a0 beq cr4,d8 <do_page_fault+0xd8>
1d4: 40 92 00 e0 bne cr4,2b4 <do_page_fault+0x2b4>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-19 20:56:30 +08:00
|
|
|
if (is_user)
|
2013-09-13 06:13:39 +08:00
|
|
|
flags |= FAULT_FLAG_USER;
|
|
|
|
|
|
2005-09-26 14:04:21 +08:00
|
|
|
/* When running in the kernel we expect faults to occur only to
|
|
|
|
|
* addresses in user space. All other faults represent errors in the
|
2006-04-01 08:33:12 +08:00
|
|
|
* kernel and should generate an OOPS. Unfortunately, in the case of an
|
|
|
|
|
* erroneous fault occurring in a code path which already holds mmap_sem
|
2005-09-26 14:04:21 +08:00
|
|
|
* we will deadlock attempting to validate the fault against the
|
|
|
|
|
* address space. Luckily the kernel only validly references user
|
|
|
|
|
* space from well defined areas of code, which are listed in the
|
|
|
|
|
* exceptions table.
|
|
|
|
|
*
|
|
|
|
|
* As the vast majority of faults will be valid we will only perform
|
2006-04-01 08:33:12 +08:00
|
|
|
* the source reference check when there is a possibility of a deadlock.
|
2005-09-26 14:04:21 +08:00
|
|
|
* Attempt to lock the address space, if we cannot we then validate the
|
|
|
|
|
* source. If this is invalid we can skip the address space check,
|
|
|
|
|
* thus avoiding the deadlock.
|
|
|
|
|
*/
|
|
|
|
|
if (!down_read_trylock(&mm->mmap_sem)) {
|
powerpc/mm: Evaluate user_mode(regs) only once in do_page_fault()
Analysis of the assembly code shows that when using user_mode(regs),
at least the 'andi.' is redone all the time, and also
the 'lwz ,132(r31)' most of the time. With the new form, the 'is_user'
is mapped to cr4, then all further use of is_user results in just
things like 'beq cr4,218 <do_page_fault+0x218>'
Without the patch:
50: 81 1e 00 84 lwz r8,132(r30)
54: 71 09 40 00 andi. r9,r8,16384
58: 40 82 00 0c bne 64 <do_page_fault+0x64>
84: 81 3e 00 84 lwz r9,132(r30)
8c: 71 2a 40 00 andi. r10,r9,16384
90: 41 a2 01 64 beq 1f4 <do_page_fault+0x1f4>
d4: 81 3e 00 84 lwz r9,132(r30)
dc: 71 28 40 00 andi. r8,r9,16384
e0: 41 82 02 08 beq 2e8 <do_page_fault+0x2e8>
108: 81 3e 00 84 lwz r9,132(r30)
110: 71 28 40 00 andi. r8,r9,16384
118: 41 82 02 28 beq 340 <do_page_fault+0x340>
1e4: 81 3e 00 84 lwz r9,132(r30)
1e8: 71 2a 40 00 andi. r10,r9,16384
1ec: 40 82 01 68 bne 354 <do_page_fault+0x354>
228: 81 3e 00 84 lwz r9,132(r30)
22c: 71 28 40 00 andi. r8,r9,16384
230: 41 82 ff c4 beq 1f4 <do_page_fault+0x1f4>
288: 71 2a 40 00 andi. r10,r9,16384
294: 41 a2 fe 60 beq f4 <do_page_fault+0xf4>
50c: 81 3e 00 84 lwz r9,132(r30)
514: 71 2a 40 00 andi. r10,r9,16384
518: 40 a2 fc e0 bne 1f8 <do_page_fault+0x1f8>
534: 81 3e 00 84 lwz r9,132(r30)
53c: 71 2a 40 00 andi. r10,r9,16384
540: 41 82 fc b8 beq 1f8 <do_page_fault+0x1f8>
This patch creates a local var called 'is_user' which contains the
result of user_mode(regs)
With the patch:
20: 81 03 00 84 lwz r8,132(r3)
48: 55 09 97 fe rlwinm r9,r8,18,31,31
58: 2e 09 00 00 cmpwi cr4,r9,0
5c: 40 92 00 0c bne cr4,68 <do_page_fault+0x68>
88: 41 b2 01 90 beq cr4,218 <do_page_fault+0x218>
d4: 40 92 01 d0 bne cr4,2a4 <do_page_fault+0x2a4>
120: 41 b2 00 f8 beq cr4,218 <do_page_fault+0x218>
138: 41 b2 ff a0 beq cr4,d8 <do_page_fault+0xd8>
1d4: 40 92 00 e0 bne cr4,2b4 <do_page_fault+0x2b4>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-19 20:56:30 +08:00
|
|
|
if (!is_user && !search_exception_tables(regs->nip))
|
2005-09-26 14:04:21 +08:00
|
|
|
goto bad_area_nosemaphore;
|
|
|
|
|
|
2012-03-01 15:14:45 +08:00
|
|
|
retry:
|
2005-09-26 14:04:21 +08:00
|
|
|
down_read(&mm->mmap_sem);
|
2012-03-07 13:48:45 +08:00
|
|
|
} else {
|
|
|
|
|
/*
|
|
|
|
|
* The above down_read_trylock() might have succeeded in
|
|
|
|
|
* which case we'll have missed the might_sleep() from
|
|
|
|
|
* down_read():
|
|
|
|
|
*/
|
|
|
|
|
might_sleep();
|
2005-09-26 14:04:21 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
vma = find_vma(mm, address);
|
|
|
|
|
if (!vma)
|
|
|
|
|
goto bad_area;
|
|
|
|
|
if (vma->vm_start <= address)
|
|
|
|
|
goto good_area;
|
|
|
|
|
if (!(vma->vm_flags & VM_GROWSDOWN))
|
|
|
|
|
goto bad_area;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* N.B. The POWER/Open ABI allows programs to access up to
|
|
|
|
|
* 288 bytes below the stack pointer.
|
|
|
|
|
* The kernel signal delivery code writes up to about 1.5kB
|
|
|
|
|
* below the stack pointer (r1) before decrementing it.
|
|
|
|
|
* The exec code can write slightly over 640kB to the stack
|
|
|
|
|
* before setting the user r1. Thus we allow the stack to
|
|
|
|
|
* expand to 1MB without further checks.
|
|
|
|
|
*/
|
|
|
|
|
if (address + 0x100000 < vma->vm_end) {
|
|
|
|
|
/* get user regs even if this fault is in kernel mode */
|
|
|
|
|
struct pt_regs *uregs = current->thread.regs;
|
|
|
|
|
if (uregs == NULL)
|
|
|
|
|
goto bad_area;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* A user-mode access to an address a long way below
|
|
|
|
|
* the stack pointer is only valid if the instruction
|
|
|
|
|
* is one which would update the stack pointer to the
|
|
|
|
|
* address accessed if the instruction completed,
|
|
|
|
|
* i.e. either stwu rs,n(r1) or stwux rs,r1,rb
|
|
|
|
|
* (or the byte, halfword, float or double forms).
|
|
|
|
|
*
|
|
|
|
|
* If we don't check this then any write to the area
|
|
|
|
|
* between the last mapped region and the stack will
|
|
|
|
|
* expand the stack rather than segfaulting.
|
|
|
|
|
*/
|
2013-09-10 21:14:42 +08:00
|
|
|
if (address + 2048 < uregs->gpr[1] && !store_update_sp)
|
2005-09-26 14:04:21 +08:00
|
|
|
goto bad_area;
|
|
|
|
|
}
|
|
|
|
|
if (expand_stack(vma, address))
|
|
|
|
|
goto bad_area;
|
|
|
|
|
|
|
|
|
|
good_area:
|
|
|
|
|
code = SEGV_ACCERR;
|
|
|
|
|
#if defined(CONFIG_6xx)
|
|
|
|
|
if (error_code & 0x95700000)
|
|
|
|
|
/* an error such as lwarx to I/O controller space,
|
|
|
|
|
address matching DABR, eciwx, etc. */
|
|
|
|
|
goto bad_area;
|
|
|
|
|
#endif /* CONFIG_6xx */
|
|
|
|
|
#if defined(CONFIG_8xx)
|
|
|
|
|
/* The MPC8xx seems to always set 0x80000000, which is
|
|
|
|
|
* "undefined". Of those that can be set, this is the only
|
|
|
|
|
* one which seems bad.
|
|
|
|
|
*/
|
|
|
|
|
if (error_code & 0x10000000)
|
|
|
|
|
/* Guarded storage error. */
|
|
|
|
|
goto bad_area;
|
|
|
|
|
#endif /* CONFIG_8xx */
|
|
|
|
|
|
|
|
|
|
if (is_exec) {
|
2007-07-19 08:00:20 +08:00
|
|
|
/*
|
|
|
|
|
* Allow execution from readable areas if the MMU does not
|
|
|
|
|
* provide separate controls over reading and executing.
|
powerpc/mm: Rework I$/D$ coherency (v3)
This patch reworks the way we do I and D cache coherency on PowerPC.
The "old" way was split in 3 different parts depending on the processor type:
- Hash with per-page exec support (64-bit and >= POWER4 only) does it
at hashing time, by preventing exec on unclean pages and cleaning pages
on exec faults.
- Everything without per-page exec support (32-bit hash, 8xx, and
64-bit < POWER4) does it for all page going to user space in update_mmu_cache().
- Embedded with per-page exec support does it from do_page_fault() on
exec faults, in a way similar to what the hash code does.
That leads to confusion, and bugs. For example, the method using update_mmu_cache()
is racy on SMP where another processor can see the new PTE and hash it in before
we have cleaned the cache, and then blow trying to execute. This is hard to hit but
I think it has bitten us in the past.
Also, it's inefficient for embedded where we always end up having to do at least
one more page fault.
This reworks the whole thing by moving the cache sync into two main call sites,
though we keep different behaviours depending on the HW capability. The call
sites are set_pte_at() which is now made out of line, and ptep_set_access_flags()
which joins the former in pgtable.c
The base idea for Embedded with per-page exec support, is that we now do the
flush at set_pte_at() time when coming from an exec fault, which allows us
to avoid the double fault problem completely (we can even improve the situation
more by implementing TLB preload in update_mmu_cache() but that's for later).
If for some reason we didn't do it there and we try to execute, we'll hit
the page fault, which will do a minor fault, which will hit ptep_set_access_flags()
to do things like update _PAGE_ACCESSED or _PAGE_DIRTY if needed, we just make
this guys also perform the I/D cache sync for exec faults now. This second path
is the catch all for things that weren't cleaned at set_pte_at() time.
For cpus without per-pag exec support, we always do the sync at set_pte_at(),
thus guaranteeing that when the PTE is visible to other processors, the cache
is clean.
For the 64-bit hash with per-page exec support case, we keep the old mechanism
for now. I'll look into changing it later, once I've reworked a bit how we
use _PAGE_EXEC.
This is also a first step for adding _PAGE_EXEC support for embedded platforms
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-11 00:02:37 +08:00
|
|
|
*
|
|
|
|
|
* Note: That code used to not be enabled for 4xx/BookE.
|
|
|
|
|
* It is now as I/D cache coherency for these is done at
|
|
|
|
|
* set_pte_at() time and I see no reason why the test
|
|
|
|
|
* below wouldn't be valid on those processors. This -may-
|
|
|
|
|
* break programs compiled with a really old ABI though.
|
2007-07-19 08:00:20 +08:00
|
|
|
*/
|
|
|
|
|
if (!(vma->vm_flags & VM_EXEC) &&
|
|
|
|
|
(cpu_has_feature(CPU_FTR_NOEXECUTE) ||
|
|
|
|
|
!(vma->vm_flags & (VM_READ | VM_WRITE))))
|
2005-09-26 14:04:21 +08:00
|
|
|
goto bad_area;
|
|
|
|
|
/* a write */
|
|
|
|
|
} else if (is_write) {
|
|
|
|
|
if (!(vma->vm_flags & VM_WRITE))
|
|
|
|
|
goto bad_area;
|
2013-09-13 06:13:39 +08:00
|
|
|
flags |= FAULT_FLAG_WRITE;
|
2005-09-26 14:04:21 +08:00
|
|
|
/* a read */
|
|
|
|
|
} else {
|
[PATCH] make PROT_WRITE imply PROT_READ
Make PROT_WRITE imply PROT_READ for a number of architectures which don't
support write only in hardware.
While looking at this, I noticed that some architectures which do not
support write only mappings already take the exact same approach. For
example, in arch/alpha/mm/fault.c:
"
if (cause < 0) {
if (!(vma->vm_flags & VM_EXEC))
goto bad_area;
} else if (!cause) {
/* Allow reads even for write-only mappings */
if (!(vma->vm_flags & (VM_READ | VM_WRITE)))
goto bad_area;
} else {
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
}
"
Thus, this patch brings other architectures which do not support write only
mappings in-line and consistent with the rest. I've verified the patch on
ia64, x86_64 and x86.
Additional discussion:
Several architectures, including x86, can not support write-only mappings.
The pte for x86 reserves a single bit for protection and its two states are
read only or read/write. Thus, write only is not supported in h/w.
Currently, if i 'mmap' a page write-only, the first read attempt on that page
creates a page fault and will SEGV. That check is enforced in
arch/blah/mm/fault.c. However, if i first write that page it will fault in
and the pte will be set to read/write. Thus, any subsequent reads to the page
will succeed. It is this inconsistency in behavior that this patch is
attempting to address. Furthermore, if the page is swapped out, and then
brought back the first read will also cause a SEGV. Thus, any arbitrary read
on a page can potentially result in a SEGV.
According to the SuSv3 spec, "if the application requests only PROT_WRITE, the
implementation may also allow read access." Also as mentioned, some
archtectures, such as alpha, shown above already take the approach that i am
suggesting.
The counter-argument to this raised by Arjan, is that the kernel is enforcing
the write only mapping the best it can given the h/w limitations. This is
true, however Alan Cox, and myself would argue that the inconsitency in
behavior, that is applications can sometimes work/sometimes fails is highly
undesireable. If you read through the thread, i think people, came to an
agreement on the last patch i posted, as nobody has objected to it...
Signed-off-by: Jason Baron <jbaron@redhat.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Andi Kleen <ak@muc.de>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Ian Molton <spyro@f2s.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 16:58:58 +08:00
|
|
|
if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
|
2005-09-26 14:04:21 +08:00
|
|
|
goto bad_area;
|
|
|
|
|
}
|
2017-01-31 00:12:59 +08:00
|
|
|
#ifdef CONFIG_PPC_STD_MMU
|
|
|
|
|
/*
|
|
|
|
|
* For hash translation mode, we should never get a
|
|
|
|
|
* PROTFAULT. Any update to pte to reduce access will result in us
|
|
|
|
|
* removing the hash page table entry, thus resulting in a DSISR_NOHPTE
|
|
|
|
|
* fault instead of DSISR_PROTFAULT.
|
|
|
|
|
*
|
|
|
|
|
* A pte update to relax the access will not result in a hash page table
|
|
|
|
|
* entry invalidate and hence can result in DSISR_PROTFAULT.
|
|
|
|
|
* ptep_set_access_flags() doesn't do a hpte flush. This is why we have
|
|
|
|
|
* the special !is_write in the below conditional.
|
|
|
|
|
*
|
|
|
|
|
* For platforms that doesn't supports coherent icache and do support
|
|
|
|
|
* per page noexec bit, we do setup things such that we do the
|
|
|
|
|
* sync between D/I cache via fault. But that is handled via low level
|
|
|
|
|
* hash fault code (hash_page_do_lazy_icache()) and we should not reach
|
|
|
|
|
* here in such case.
|
|
|
|
|
*
|
|
|
|
|
* For wrong access that can result in PROTFAULT, the above vma->vm_flags
|
|
|
|
|
* check should handle those and hence we should fall to the bad_area
|
|
|
|
|
* handling correctly.
|
|
|
|
|
*
|
|
|
|
|
* For embedded with per page exec support that doesn't support coherent
|
|
|
|
|
* icache we do get PROTFAULT and we handle that D/I cache sync in
|
|
|
|
|
* set_pte_at while taking the noexec/prot fault. Hence this is WARN_ON
|
|
|
|
|
* is conditional for server MMU.
|
|
|
|
|
*
|
|
|
|
|
* For radix, we can get prot fault for autonuma case, because radix
|
|
|
|
|
* page table will have them marked noaccess for user.
|
|
|
|
|
*/
|
|
|
|
|
if (!radix_enabled() && !is_write)
|
|
|
|
|
WARN_ON_ONCE(error_code & DSISR_PROTFAULT);
|
|
|
|
|
#endif /* CONFIG_PPC_STD_MMU */
|
2005-09-26 14:04:21 +08:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* If for any reason at all we couldn't handle the fault,
|
|
|
|
|
* make sure we exit gracefully rather than endlessly redo
|
|
|
|
|
* the fault.
|
|
|
|
|
*/
|
2016-07-27 06:25:18 +08:00
|
|
|
fault = handle_mm_fault(vma, address, flags);
|
2017-02-15 00:45:11 +08:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Handle the retry right now, the mmap_sem has been released in that
|
|
|
|
|
* case.
|
|
|
|
|
*/
|
|
|
|
|
if (unlikely(fault & VM_FAULT_RETRY)) {
|
|
|
|
|
/* We retry only once */
|
|
|
|
|
if (flags & FAULT_FLAG_ALLOW_RETRY) {
|
|
|
|
|
/*
|
|
|
|
|
* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk
|
|
|
|
|
* of starvation.
|
|
|
|
|
*/
|
|
|
|
|
flags &= ~FAULT_FLAG_ALLOW_RETRY;
|
|
|
|
|
flags |= FAULT_FLAG_TRIED;
|
|
|
|
|
if (!fatal_signal_pending(current))
|
|
|
|
|
goto retry;
|
|
|
|
|
}
|
|
|
|
|
/* We will enter mm_fault_error() below */
|
2017-02-15 00:45:12 +08:00
|
|
|
} else
|
|
|
|
|
up_read(¤t->mm->mmap_sem);
|
2017-02-15 00:45:11 +08:00
|
|
|
|
2012-03-01 15:14:45 +08:00
|
|
|
if (unlikely(fault & (VM_FAULT_RETRY|VM_FAULT_ERROR))) {
|
vm: add VM_FAULT_SIGSEGV handling support
The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.
That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works. However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.
In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV. And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.
However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d4514 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space. And user space really
expected SIGSEGV, not SIGBUS.
To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it. They all already have
the code to handle SIGSEGV, so it's about just tying that new return
value to the existing code, but it's all a bit annoying.
This is the mindless minimal patch to do this. A more extensive patch
would be to try to gather up the mostly shared fault handling logic into
one generic helper routine, and long-term we really should do that
cleanup.
Just from this patch, you can generally see that most architectures just
copied (directly or indirectly) the old x86 way of doing things, but in
the meantime that original x86 model has been improved to hold the VM
semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
"newer" things, so it would be a good idea to bring all those
improvements to the generic case and teach other architectures about
them too.
Reported-and-tested-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-01-30 02:51:32 +08:00
|
|
|
if (fault & VM_FAULT_SIGSEGV)
|
2017-02-15 00:45:12 +08:00
|
|
|
goto bad_area_nosemaphore;
|
powerpc: Exception hooks for context tracking subsystem
This is the exception hooks for context tracking subsystem, including
data access, program check, single step, instruction breakpoint, machine check,
alignment, fp unavailable, altivec assist, unknown exception, whose handlers
might use RCU.
This patch corresponds to
[PATCH] x86: Exception hooks for userspace RCU extended QS
commit 6ba3c97a38803883c2eee489505796cb0a727122
But after the exception handling moved to generic code, and some changes in
following two commits:
56dd9470d7c8734f055da2a6bac553caf4a468eb
context_tracking: Move exception handling to generic code
6c1e0256fad84a843d915414e4b5973b7443d48d
context_tracking: Restore correct previous context state on exception exit
it is able for exception hooks to use the generic code above instead of a
redundant arch implementation.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 00:16:41 +08:00
|
|
|
rc = mm_fault_error(regs, address, fault);
|
2012-03-01 15:14:45 +08:00
|
|
|
if (rc >= MM_FAULT_RETURN)
|
powerpc: Exception hooks for context tracking subsystem
This is the exception hooks for context tracking subsystem, including
data access, program check, single step, instruction breakpoint, machine check,
alignment, fp unavailable, altivec assist, unknown exception, whose handlers
might use RCU.
This patch corresponds to
[PATCH] x86: Exception hooks for userspace RCU extended QS
commit 6ba3c97a38803883c2eee489505796cb0a727122
But after the exception handling moved to generic code, and some changes in
following two commits:
56dd9470d7c8734f055da2a6bac553caf4a468eb
context_tracking: Move exception handling to generic code
6c1e0256fad84a843d915414e4b5973b7443d48d
context_tracking: Restore correct previous context state on exception exit
it is able for exception hooks to use the generic code above instead of a
redundant arch implementation.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 00:16:41 +08:00
|
|
|
goto bail;
|
|
|
|
|
else
|
|
|
|
|
rc = 0;
|
2005-09-26 14:04:21 +08:00
|
|
|
}
|
2012-03-01 15:14:45 +08:00
|
|
|
|
|
|
|
|
/*
|
2017-02-15 00:45:11 +08:00
|
|
|
* Major/minor page fault accounting.
|
2012-03-01 15:14:45 +08:00
|
|
|
*/
|
2017-02-15 00:45:11 +08:00
|
|
|
if (fault & VM_FAULT_MAJOR) {
|
|
|
|
|
current->maj_flt++;
|
|
|
|
|
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1,
|
|
|
|
|
regs, address);
|
2008-10-22 13:53:45 +08:00
|
|
|
#ifdef CONFIG_PPC_SMLPAR
|
2017-02-15 00:45:11 +08:00
|
|
|
if (firmware_has_feature(FW_FEATURE_CMO)) {
|
|
|
|
|
u32 page_ins;
|
|
|
|
|
|
|
|
|
|
preempt_disable();
|
|
|
|
|
page_ins = be32_to_cpu(get_lppaca()->page_ins);
|
|
|
|
|
page_ins += 1 << PAGE_FACTOR;
|
|
|
|
|
get_lppaca()->page_ins = cpu_to_be32(page_ins);
|
|
|
|
|
preempt_enable();
|
2008-10-22 13:53:45 +08:00
|
|
|
}
|
2017-02-15 00:45:11 +08:00
|
|
|
#endif /* CONFIG_PPC_SMLPAR */
|
|
|
|
|
} else {
|
|
|
|
|
current->min_flt++;
|
|
|
|
|
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1,
|
|
|
|
|
regs, address);
|
2009-03-13 19:21:34 +08:00
|
|
|
}
|
2012-03-01 15:14:45 +08:00
|
|
|
|
powerpc: Exception hooks for context tracking subsystem
This is the exception hooks for context tracking subsystem, including
data access, program check, single step, instruction breakpoint, machine check,
alignment, fp unavailable, altivec assist, unknown exception, whose handlers
might use RCU.
This patch corresponds to
[PATCH] x86: Exception hooks for userspace RCU extended QS
commit 6ba3c97a38803883c2eee489505796cb0a727122
But after the exception handling moved to generic code, and some changes in
following two commits:
56dd9470d7c8734f055da2a6bac553caf4a468eb
context_tracking: Move exception handling to generic code
6c1e0256fad84a843d915414e4b5973b7443d48d
context_tracking: Restore correct previous context state on exception exit
it is able for exception hooks to use the generic code above instead of a
redundant arch implementation.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 00:16:41 +08:00
|
|
|
goto bail;
|
2005-09-26 14:04:21 +08:00
|
|
|
|
|
|
|
|
bad_area:
|
|
|
|
|
up_read(&mm->mmap_sem);
|
|
|
|
|
|
|
|
|
|
bad_area_nosemaphore:
|
|
|
|
|
/* User mode accesses cause a SIGSEGV */
|
powerpc/mm: Evaluate user_mode(regs) only once in do_page_fault()
Analysis of the assembly code shows that when using user_mode(regs),
at least the 'andi.' is redone all the time, and also
the 'lwz ,132(r31)' most of the time. With the new form, the 'is_user'
is mapped to cr4, then all further use of is_user results in just
things like 'beq cr4,218 <do_page_fault+0x218>'
Without the patch:
50: 81 1e 00 84 lwz r8,132(r30)
54: 71 09 40 00 andi. r9,r8,16384
58: 40 82 00 0c bne 64 <do_page_fault+0x64>
84: 81 3e 00 84 lwz r9,132(r30)
8c: 71 2a 40 00 andi. r10,r9,16384
90: 41 a2 01 64 beq 1f4 <do_page_fault+0x1f4>
d4: 81 3e 00 84 lwz r9,132(r30)
dc: 71 28 40 00 andi. r8,r9,16384
e0: 41 82 02 08 beq 2e8 <do_page_fault+0x2e8>
108: 81 3e 00 84 lwz r9,132(r30)
110: 71 28 40 00 andi. r8,r9,16384
118: 41 82 02 28 beq 340 <do_page_fault+0x340>
1e4: 81 3e 00 84 lwz r9,132(r30)
1e8: 71 2a 40 00 andi. r10,r9,16384
1ec: 40 82 01 68 bne 354 <do_page_fault+0x354>
228: 81 3e 00 84 lwz r9,132(r30)
22c: 71 28 40 00 andi. r8,r9,16384
230: 41 82 ff c4 beq 1f4 <do_page_fault+0x1f4>
288: 71 2a 40 00 andi. r10,r9,16384
294: 41 a2 fe 60 beq f4 <do_page_fault+0xf4>
50c: 81 3e 00 84 lwz r9,132(r30)
514: 71 2a 40 00 andi. r10,r9,16384
518: 40 a2 fc e0 bne 1f8 <do_page_fault+0x1f8>
534: 81 3e 00 84 lwz r9,132(r30)
53c: 71 2a 40 00 andi. r10,r9,16384
540: 41 82 fc b8 beq 1f8 <do_page_fault+0x1f8>
This patch creates a local var called 'is_user' which contains the
result of user_mode(regs)
With the patch:
20: 81 03 00 84 lwz r8,132(r3)
48: 55 09 97 fe rlwinm r9,r8,18,31,31
58: 2e 09 00 00 cmpwi cr4,r9,0
5c: 40 92 00 0c bne cr4,68 <do_page_fault+0x68>
88: 41 b2 01 90 beq cr4,218 <do_page_fault+0x218>
d4: 40 92 01 d0 bne cr4,2a4 <do_page_fault+0x2a4>
120: 41 b2 00 f8 beq cr4,218 <do_page_fault+0x218>
138: 41 b2 ff a0 beq cr4,d8 <do_page_fault+0xd8>
1d4: 40 92 00 e0 bne cr4,2b4 <do_page_fault+0x2b4>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-19 20:56:30 +08:00
|
|
|
if (is_user) {
|
2005-09-26 14:04:21 +08:00
|
|
|
_exception(SIGSEGV, regs, code, address);
|
powerpc: Exception hooks for context tracking subsystem
This is the exception hooks for context tracking subsystem, including
data access, program check, single step, instruction breakpoint, machine check,
alignment, fp unavailable, altivec assist, unknown exception, whose handlers
might use RCU.
This patch corresponds to
[PATCH] x86: Exception hooks for userspace RCU extended QS
commit 6ba3c97a38803883c2eee489505796cb0a727122
But after the exception handling moved to generic code, and some changes in
following two commits:
56dd9470d7c8734f055da2a6bac553caf4a468eb
context_tracking: Move exception handling to generic code
6c1e0256fad84a843d915414e4b5973b7443d48d
context_tracking: Restore correct previous context state on exception exit
it is able for exception hooks to use the generic code above instead of a
redundant arch implementation.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 00:16:41 +08:00
|
|
|
goto bail;
|
2005-09-26 14:04:21 +08:00
|
|
|
}
|
|
|
|
|
|
2011-06-04 13:36:54 +08:00
|
|
|
if (is_exec && (error_code & DSISR_PROTFAULT))
|
|
|
|
|
printk_ratelimited(KERN_CRIT "kernel tried to execute NX-protected"
|
|
|
|
|
" page (%lx) - exploit attempt? (uid: %d)\n",
|
2012-08-07 18:59:47 +08:00
|
|
|
address, from_kuid(&init_user_ns, current_uid()));
|
2005-09-26 14:04:21 +08:00
|
|
|
|
powerpc: Exception hooks for context tracking subsystem
This is the exception hooks for context tracking subsystem, including
data access, program check, single step, instruction breakpoint, machine check,
alignment, fp unavailable, altivec assist, unknown exception, whose handlers
might use RCU.
This patch corresponds to
[PATCH] x86: Exception hooks for userspace RCU extended QS
commit 6ba3c97a38803883c2eee489505796cb0a727122
But after the exception handling moved to generic code, and some changes in
following two commits:
56dd9470d7c8734f055da2a6bac553caf4a468eb
context_tracking: Move exception handling to generic code
6c1e0256fad84a843d915414e4b5973b7443d48d
context_tracking: Restore correct previous context state on exception exit
it is able for exception hooks to use the generic code above instead of a
redundant arch implementation.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 00:16:41 +08:00
|
|
|
rc = SIGSEGV;
|
|
|
|
|
|
|
|
|
|
bail:
|
|
|
|
|
exception_exit(prev_state);
|
|
|
|
|
return rc;
|
2005-09-26 14:04:21 +08:00
|
|
|
}
|
2016-09-16 18:48:08 +08:00
|
|
|
NOKPROBE_SYMBOL(do_page_fault);
|
2005-09-26 14:04:21 +08:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* bad_page_fault is called when we have a bad access from the kernel.
|
|
|
|
|
* It is called from the DSI and ISI handlers in head.S and from some
|
|
|
|
|
* of the procedures in traps.c.
|
|
|
|
|
*/
|
|
|
|
|
void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
|
|
|
|
|
{
|
|
|
|
|
const struct exception_table_entry *entry;
|
|
|
|
|
|
|
|
|
|
/* Are we prepared to handle this fault? */
|
|
|
|
|
if ((entry = search_exception_tables(regs->nip)) != NULL) {
|
2016-10-14 13:47:31 +08:00
|
|
|
regs->nip = extable_fixup(entry);
|
2005-09-26 14:04:21 +08:00
|
|
|
return;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* kernel has accessed a bad area */
|
2005-11-07 06:54:36 +08:00
|
|
|
|
|
|
|
|
switch (regs->trap) {
|
2006-11-08 07:22:59 +08:00
|
|
|
case 0x300:
|
|
|
|
|
case 0x380:
|
|
|
|
|
printk(KERN_ALERT "Unable to handle kernel paging request for "
|
|
|
|
|
"data at address 0x%08lx\n", regs->dar);
|
|
|
|
|
break;
|
|
|
|
|
case 0x400:
|
|
|
|
|
case 0x480:
|
|
|
|
|
printk(KERN_ALERT "Unable to handle kernel paging request for "
|
|
|
|
|
"instruction fetch\n");
|
|
|
|
|
break;
|
2015-07-02 12:56:20 +08:00
|
|
|
case 0x600:
|
|
|
|
|
printk(KERN_ALERT "Unable to handle kernel paging request for "
|
|
|
|
|
"unaligned access at address 0x%08lx\n", regs->dar);
|
|
|
|
|
break;
|
2006-11-08 07:22:59 +08:00
|
|
|
default:
|
|
|
|
|
printk(KERN_ALERT "Unable to handle kernel paging request for "
|
|
|
|
|
"unknown fault\n");
|
|
|
|
|
break;
|
2005-11-07 06:54:36 +08:00
|
|
|
}
|
|
|
|
|
printk(KERN_ALERT "Faulting instruction address: 0x%08lx\n",
|
|
|
|
|
regs->nip);
|
|
|
|
|
|
2014-09-12 21:16:18 +08:00
|
|
|
if (task_stack_end_corrupted(current))
|
2010-08-24 21:15:28 +08:00
|
|
|
printk(KERN_ALERT "Thread overran stack, or stack corrupted\n");
|
|
|
|
|
|
2005-09-26 14:04:21 +08:00
|
|
|
die("Kernel access of bad area", regs, sig);
|
|
|
|
|
}
|