On Wed, Dec 17, 2008 at 11:46:05PM +0100, Helge Deller wrote:
>
Honestly, I can't decide whether to apply this. It really should never
happen in the kernel, since the kernel can guarantee it won't get the
access rights failure (highest privilege level, and can set %sr and
%protid to whatever it wants.)
It really genuinely is a bug that probably should panic the kernel. The
only precedent I can easily see is x86 fixing up a bad iret with a
general protection fault, which is more or less analogous to code 27
here.
On the other hand, taking the exception on a userspace access really
isn't all that critical, and there's fundamentally little reason for the
kernel not to SIGSEGV the process, and continue...
Argh.
(btw, I've instrumented my do_sys_poll with a pile of assertions that
%cr8 << 1 == %sr3 == current->mm.context... let's see if where we're
getting corrupted is deterministic, though, I would guess that it won't
be.)
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
Any user on existing parisc 32- and 64bit-kernels can easily crash
the kernel and as such enforce a DSO.
A simple testcase is available here:
http://gsyprf10.external.hp.com/~deller/crash.tgz
The problem is introduced by the fact, that the handle_interruption()
crash handler calls the show_regs() function, which in turn tries to
unwind the stack by calling parisc_show_stack(). Since the stack contains
userspace addresses, a try to unwind the stack is dangerous and useless
and leads to the crash.
The fix is trivial: For userspace processes
a) avoid to unwind the stack, and
b) avoid to resolve userspace addresses to kernel symbol names.
While touching this code, I converted print_symbol() to %pS
printk formats and made parisc_show_stack() static.
An initial patch for this was written by Kyle McMartin back in August:
http://marc.info/?l=linux-parisc&m=121805168830283&w=2
Compile and run-tested with a 64bit parisc kernel.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x, 2.6.27.x, earlier...]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <willy@debian.org>
Cc: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
When we show_regs, we obviously have a struct pt_regs of the calling
frame. Use these in show_stack so we don't have the entire bogus call trace
up to the show_stack call.
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
Originally, show_stack was used in BUG() output. However, a recent commit
changed it to print register state (no idea what that's supposed to help,
really...) and parisc was missing a backtrace because of it.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
One of the easiest things to isolate is the pid printed in kernel log.
There was a patch, that made this for arch-independent code, this one makes
so for arch/xxx files.
It took some time to cross-compile it, but hopefully these are all the
printks in arch code.
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the kernel OOPSed or BUGed then it probably should be considered as
tainted. Thus, all subsequent OOPSes and SysRq dumps will report the
tainted kernel. This saves a lot of time explaining oddities in the
calltraces.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Added parisc patch from Matthew Wilson -Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current generic bug implementation has a call to dump_stack() in case a
WARN_ON(whatever) gets hit. Since report_bug(), which calls dump_stack(),
gets called from an exception handler we can do better: just pass the
pt_regs structure to report_bug() and pass it to show_regs() in case of a
warning. This will give more debug informations like register contents,
etc... In addition this avoids some pointless lines that dump_stack()
emits, since it includes a stack backtrace of the exception handler which
is of no interest in case of a warning. E.g. on s390 the following lines
are currently always present in a stack backtrace if dump_stack() gets
called from report_bug():
[<000000000001517a>] show_trace+0x92/0xe8)
[<0000000000015270>] show_stack+0xa0/0xd0
[<00000000000152ce>] dump_stack+0x2e/0x3c
[<0000000000195450>] report_bug+0x98/0xf8
[<0000000000016cc8>] illegal_op+0x1fc/0x21c
[<00000000000227d6>] sysc_return+0x0/0x10
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
check_ivt had some seriously broken code wrt function pointers on
parisc64. Instead of referencing the hpmc code via a function pointer,
export symbols and reference it as a const array.
Thanks to jda for pointing out the broken 64-bit func ptr handling.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.
Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
show_stack() was calling kzalloc() to allocate a struct pt_regs.
This meant that *really* early stack dumps would cause a null pointer
dereference. x86_64 allocates its pt_regs on the stack, so do the same.
Kyle actually committed this exact patch to CVS on
Wed Jul 26 14:32:39 2006 UTC, and never moved it across to git.
Bad Kyle.
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
show_regs() was one bloaty function. Split it into a few cleaner
functions and define a clean macro to print a line of registers.
[And from Thibaut, only print fprs on a usermode trap.]
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Helge,
o Convert a bunch of kmalloc/memset uses to kzalloc.
o pci.c: Add some __read_mostly annotations.
o pci.c: Move constant pci_post_reset_delay to asm/pci.h
o grfioctl.h: Add A4450A to comment of CRT_ID_VISUALIZE_EG.
o Add some consts to perf.c/perf_images.h
Matthew,
o sticore.c: Add some consts to suppress compile warnings.
Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
We're using fp regs now in the kernel, so we want to print them
on stack dump
Signed-off-by: Thibaut VARENE <varenet@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
