One of the debian buildd servers had this crash in the syslog without
any other information:
Unaligned handler failed, ret = -2
clock_adjtime (pid 22578): Unaligned data reference (code 28)
CPU: 1 PID: 22578 Comm: clock_adjtime Tainted: G E 4.5.0-2-parisc64-smp #1 Debian 4.5.4-1
task: 000000007d9960f8 ti: 00000001bde7c000 task.ti: 00000001bde7c000
YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00001000000001001111100000001111 Tainted: G E
r00-03 000000ff0804f80f 00000001bde7c2b0 00000000402d2be8 00000001bde7c2b0
r04-07 00000000409e1fd0 00000000fa6f7fff 00000001bde7c148 00000000fa6f7fff
r08-11 0000000000000000 00000000ffffffff 00000000fac9bb7b 000000000002b4d4
r12-15 000000000015241c 000000000015242c 000000000000002d 00000000fac9bb7b
r16-19 0000000000028800 0000000000000001 0000000000000070 00000001bde7c218
r20-23 0000000000000000 00000001bde7c210 0000000000000002 0000000000000000
r24-27 0000000000000000 0000000000000000 00000001bde7c148 00000000409e1fd0
r28-31 0000000000000001 00000001bde7c320 00000001bde7c350 00000001bde7c218
sr00-03 0000000001200000 0000000001200000 0000000000000000 0000000001200000
sr04-07 0000000000000000 0000000000000000 0000000000000000 0000000000000000
IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000402d2e84 00000000402d2e88
IIR: 0ca0d089 ISR: 0000000001200000 IOR: 00000000fa6f7fff
CPU: 1 CR30: 00000001bde7c000 CR31: ffffffffffffffff
ORIG_R28: 00000002369fe628
IAOQ[0]: compat_get_timex+0x2dc/0x3c0
IAOQ[1]: compat_get_timex+0x2e0/0x3c0
RP(r2): compat_get_timex+0x40/0x3c0
Backtrace:
[<00000000402d4608>] compat_SyS_clock_adjtime+0x40/0xc0
[<0000000040205024>] syscall_exit+0x0/0x14
This means the userspace program clock_adjtime called the clock_adjtime()
syscall and then crashed inside the compat_get_timex() function.
Syscalls should never crash programs, but instead return EFAULT.
The IIR register contains the executed instruction, which disassebles
into "ldw 0(sr3,r5),r9".
This load-word instruction is part of __get_user() which tried to read the word
at %r5/IOR (0xfa6f7fff). This means the unaligned handler jumped in. The
unaligned handler is able to emulate all ldw instructions, but it fails if it
fails to read the source e.g. because of page fault.
The following program reproduces the problem:
#define _GNU_SOURCE
#include <unistd.h>
#include <sys/syscall.h>
#include <sys/mman.h>
int main(void) {
/* allocate 8k */
char *ptr = mmap(NULL, 2*4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
/* free second half (upper 4k) and make it invalid. */
munmap(ptr+4096, 4096);
/* syscall where first int is unaligned and clobbers into invalid memory region */
/* syscall should return EFAULT */
return syscall(__NR_clock_adjtime, 0, ptr+4095);
}
To fix this issue we simply need to check if the faulting instruction address
is in the exception fixup table when the unaligned handler failed. If it
is, call the fixup routine instead of crashing.
While looking at the unaligned handler I found another issue as well: The
target register should not be modified if the handler was unsuccessful.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
This patch fixes backtrace on PA-RISC
There were several problems:
1) The code that decodes instructions handles instructions that subtract
from the stack pointer incorrectly. If the instruction subtracts the
number X from the stack pointer the code increases the frame size by
(0x100000000-X). This results in invalid accesses to memory and
recursive page faults.
2) Because gcc reorders blocks, handling instructions that subtract from
the frame pointer is incorrect. For example, this function
int f(int a)
{
if (__builtin_expect(a, 1))
return a;
g();
return a;
}
is compiled in such a way, that the code that decreases the stack
pointer for the first "return a" is placed before the code for "g" call.
If we recognize this decrement, we mistakenly believe that the frame
size for the "g" call is zero.
To fix problems 1) and 2), the patch doesn't recognize instructions that
decrease the stack pointer at all. To further safeguard the unwind code
against nonsense values, we don't allow frame size larger than
Total_frame_size.
3) The backtrace is not locked. If stack dump races with module unload,
invalid table can be accessed.
This patch adds a spinlock when processing module tables.
Note, that for correct backtrace, you need recent binutils.
Binutils 2.18 from Debian 5 produce garbage unwind tables.
Binutils 2.21 work better (it sometimes forgets function frames, but at
least it doesn't generate garbage).
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Depending on config options we will need to use a long jump to reach
ftrace_return_to_handler(). Additionally only compile the
parisc_return_to_handler code when CONFIG_FUNCTION_GRAPH_TRACER is set.
Signed-off-by: Helge Deller <deller@gmx.de>
When enabling all-branch ftrace support (CONFIG_PROFILE_ALL_BRANCHES)
the kernel gets really huge and some ftrace assembler functions like
mcount can't reach the ftrace helper functions which are written in C.
Avoid this problem of too distant branches by moving the ftrace C-helper
functions into the .text.hot section which is put in front of the
standard .text section by the linker.
Signed-off-by: Helge Deller <deller@gmx.de>
Add a native implementation for the sched_clock() function which utilizes the
processor-internal cycle counter (Control Register 16) as high-resolution time
source.
With this patch we now get much more fine-grained resolutions in various
in-kernel time measurements (e.g. when viewing the function tracing logs), and
probably a more accurate scheduling on SMP systems.
There are a few specific implementation details in this patch:
1. On a 32bit kernel we emulate the higher 32bits of the required 64-bit
resolution of sched_clock() by increasing a per-cpu counter at every
wrap-around of the 32bit cycle counter.
2. In a SMP system, the cycle counters of the various CPUs are not syncronized
(similiar to the TSC in a x86_64 system). To cope with this we define
HAVE_UNSTABLE_SCHED_CLOCK and let the upper layers do the adjustment work.
3. Since we need HAVE_UNSTABLE_SCHED_CLOCK, we need to provide a cmpxchg64()
function even on a 32-bit kernel.
4. A 64-bit SMP kernel which is started on a UP system will mark the
sched_clock() implementation as "stable", which means that we don't expect any
jumps in the returned counter. This is true because we then run only on one
CPU.
Signed-off-by: Helge Deller <deller@gmx.de>
By adding TRACEHOOK support we now get a clean user interface to access
registers via PTRACE_GETREGS, PTRACE_SETREGS, PTRACE_GETFPREGS and
PTRACE_SETFPREGS.
The user-visible regset struct user_regs_struct and user_fp_struct are
modelled similiar to x86 and can be accessed via PTRACE_GETREGSET.
Signed-off-by: Helge Deller <deller@gmx.de>
This patch adds support for the TIF_SYSCALL_TRACEPOINT on the parisc
architecture. Basically, it calls the appropriate tracepoints on syscall
entry and exit.
Signed-off-by: Helge Deller <deller@gmx.de>
Define HAVE_EXIT_THREAD for archs which want to do something in
exit_thread. For others, let's define exit_thread as an empty inline.
This is a cleanup before we change the prototype of exit_thread to
accept a task parameter.
[akpm@linux-foundation.org: fix mips]
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Howells <dhowells@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Do not load one entry beyond the end of the syscall table when the
syscall number of a traced process equals to __NR_Linux_syscalls.
Similar bug with regular processes was fixed by commit 3bb457af4f
("[PARISC] Fix bug when syscall nr is __NR_Linux_syscalls").
This bug was found by strace test suite.
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Pull parisc ftrace fixes from Helge Deller:
"This is (most likely) the last pull request for v4.6 for the parisc
architecture.
It fixes the FTRACE feature for parisc, which is horribly broken since
quite some time and doesn't even compile. This patch just fixes the
bare minimum (it actually removes more lines than it adds), so that
the function tracer works again on 32- and 64bit kernels.
I've queued up additional patches on top of this patch which e.g. add
the syscall tracer, but those have to wait for the merge window for
v4.7."
* 'parisc-4.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Fix ftrace function tracer
Fix the FTRACE function tracer for 32- and 64-bit kernel.
The former code was horribly broken.
Reimplement most coding in assembly and utilize optimizations, e.g. put
mcount() and ftrace_stub() into one L1 cacheline.
Signed-off-by: Helge Deller <deller@gmx.de>
Handling exceptions from modules never worked on parisc.
It was just masked by the fact that exceptions from modules
don't happen during normal use.
When a module triggers an exception in get_user() we need to load the
main kernel dp value before accessing the exception_data structure, and
afterwards restore the original dp value of the module on exit.
Noticed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
The kernel module testcase (lib/test_user_copy.c) exhibited a kernel
crash on parisc if the parameters for copy_from_user were reversed
("illegal reversed copy_to_user" testcase).
Fix this potential crash by checking the fault handler if the faulting
address is in the exception table.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>
We want to avoid the kernel module loader to create function pointers
for the kernel fixup routines of get_user() and put_user(). Changing
the external reference from function type to int type fixes this.
This unbreaks exception handling for get_user() and put_user() when
called from a kernel module.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
Commit 0de7985 (parisc: Use generic extable search and sort routines)
changed the exception tables to use 32bit relative offsets.
This patch now adds support to the kernel module loader to handle such
R_PARISC_PCREL32 relocations for 32- and 64-bit modules.
Signed-off-by: Helge Deller <deller@gmx.de>
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull parisc fixes from Helge Deller:
"Fix seccomp filter support and SIGSYS signals on compat kernel.
Both patches are tagged for v4.5 stable kernel"
* 'parisc-4.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Fix and enable seccomp filter support
parisc: Fix SIGSYS signals in compat case
The seccomp filter support requires careful handling of task registers. This
includes reloading of the return value (%r28) and proper syscall exit if
secure_computing() returned -1.
Additionally we need to sign-extend the syscall number from signed 32bit to
signed 64bit in do_syscall_trace_enter() since the ptrace interface only allows
storing 32bit values in compat mode.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v4.5
KASAN needs to know whether the allocation happens in an IRQ handler.
This lets us strip everything below the IRQ entry point to reduce the
number of unique stack traces needed to be stored.
Move the definition of __irq_entry to <linux/interrupt.h> so that the
users don't need to pull in <linux/ftrace.h>. Also introduce the
__softirq_entry macro which is similar to __irq_entry, but puts the
corresponding functions to the .softirqentry.text section.
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PA-RISC wants to sleep 5 seconds before panicking when panic_on_oops
is set, with no apparent reason. Remove this feature, since some users
may want their systems to fail as quickly as possible.
Users who want to delay reboot after panic can use PANIC_TIMEOUT.
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Helge Deller <deller@gmx.de>
The system calls alloc_hugepages() and free_hugepages() were introduced
in Linux 2.5.36 and removed again in 2.5.54. They were never implemented
on parisc, so let's drop them now.
Signed-off-by: Helge Deller <deller@gmx.de>
Helge Deller
Mikulas Patocka
Jiri Slaby
Dmitry V. Levin
Linus Torvalds
Kirill A. Shutemov
Alexander Potapenko
Aaro Koskinen