Commit 66759a01ad introduced the fix for
time ticking too fast on some boards by disabling one of the doubly
connected timer pins on ATI boards.
However, it ends up being _much_ too broad a brush, and that just makes
some other ATI boards not work at all since they now have no timer
source.
So disable the automatic ATI southbridge detection, and just rely on
people who see this problem disabling it by hand with the option
"disable_timer_pin_1" on the kernel command line.
Maybe somebody can figure out the proper tests at a later date.
Acked-by: Peter Osterlund <petero2@telia.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
disable_timer_pin_1 needs IO-APIC, not just local APIC.
Signed-off-by: Cal Peake <cp@absolutedigital.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Masked FPU exceptions should obviously not happen in the first place,
but if they do, ignoring them seems to be the right thing to do.
Although there is no documentation available for Cyrix MII, I did find
erratum F-7 for Winchip C6, "FPU instruction may result in spurious
exception under certain conditions" which seems to indicate that this
can happen.
That would also explain the behaviour Ondrej Zary reported on the MII.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use the add_taint() interface for setting tainted bit flags instead of
doing it manually.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
ACPI earlyquirks needs to honor the proper config variables, and include
the right header file.
(Fixes commit 66759a01ad)
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Original patch from Bertro Simul
This is probably still not quite correct, but seems to be
the best solution so far.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Now that Greg implemented MCFG/_SEG support this shouldn't be needed
anymore
Cc: gregkh@suse.de
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Inside the linker script, insert the code for DWARF debug info sections. This
may help GDB'ing a Uml binary. Actually, it seems that ld is able to guess
what I added correctly, but normal linker scripts include this section so it
should be correct anyway adding it.
On request by Sam Ravnborg <sam@ravnborg.org>, I've added it to
asm-generic/vmlinux.lds.s. I've also moved there the stabs debug section,
used the new macro in i386 linker script and added DWARF debug section to
that.
In the truth, I've not been able to verify the difference in GDB behaviour
after this change (I've seen large improvements with another patch). This
may depend on my binutils version, older one may have worse defaults.
However, this section is present in normal linker script, so add it at
least for the sake of cleanness.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
get_cpu_vendor() no longer has any users in other files.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove S4BIOS support. It is pretty useless, and only ever worked for _me_
once. (I do not think anyone else ever tried it). It was in feature-removal
for a long time, and it should have been removed before.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Replace schedule_timeout() with msleep() to guarantee the task delays as
expected.
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This fixes the problem with "Averatec 6240 pcmcia_socket0: unable to
apply power", which was due to the CardBus IOMEM register region being
allocated at an address that was actually inside the RAM window that had
been reserved for video frame-buffers in an UMA setup.
The BIOS _should_ have marked that region reserved in the e820 memory
descriptor tables, but did not.
It is fixed by rounding up the default starting address of PCI memory
allocations, so that we leave a bigger gap after the final known memory
location. The amount of rounding depends on how big the unused memory
gap is that we can allocate IOMEM from.
Based on example code by Linus.
Acked-by: Greg KH <greg@kroah.com>
Acked-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Clean up timer initialization by introducing DEFINE_TIMER a'la
DEFINE_SPINLOCK. Build and boot-tested on x86. A similar patch has been
been in the -RT tree for some time.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
For the i386, code is already present in video.S that gets the EDID from the
video BIOS. Make this visible so drivers can also use this data as fallback
when i2c does not work.
To ensure that the EDID block is returned for the primary graphics adapter
only, by check if the IORESOURCE_ROM_SHADOW flag is set.
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add rudimentary support by manipulating the VGA registers. However, not
all vesa modes are VGA compatible, so VGA compatiblity is checked first.
Only 2 levels are supported, powerup and powerdown.
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is the same issue as ppc64 before, when returning to userland we
shouldn't re-compute the seccomp check or the task could be killed during
sigreturn when orig_eax is overwritten by the sigreturn syscall. This was
found by Roland.
This was harmless from a security standpoint, but some i686 users reported
failures with auditing enabled system wide (some distro surprisingly makes
it the default) and I reproduced it too by keeping the whole workload under
strace -f.
Patch is tested and works for me under strace -f.
nobody@athlon:~/cpushare> strace -o /tmp/o -f python seccomp_test.py
make: Nothing to be done for `seccomp_test'.
Starting computing some malicious bytecode
init
load
start
stop
receive_data failure
kill
exit_code 0 signal 9
The malicious bytecode has been killed successfully by seccomp
Starting computing some safe bytecode
init
load
start
stop
174 counts
kill
exit_code 0 signal 0
The seccomp_test.py completed successfully, thank you for testing.
(akpm: collaterally cleaned up a bit of do_syscall_trace() too)
Signed-off-by: Andrea Arcangeli <andrea@cpushare.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove the weird and apparently unnecessary logic in MP_processor_info() which
assumes that the BSP is the first one to run MP_processor_info(). On one of
my boxes that isn't true and cpu_possible_map gets the wrong value.
Cc: Zwane Mwaikambo <zwane@arm.linux.org.uk>
Cc: Alexander Nyberg <alexn@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Building asm-offsets.h has been moved to a seperate Kbuild file
located in the top-level directory. This allow us to share the
functionality across the architectures.
The old rules in architecture specific Makefiles will die
in subsequent patches.
Furhtermore the usual kbuild dependency tracking is now used
when deciding to rebuild asm-offsets.s. So we no longer risk
to fail a rebuild caused by asm-offsets.c dependencies being touched.
With this common rule-set we now force the same name across
all architectures. Following patches will fix the rest.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Convert i386/pci to use io_remap_pfn_range instead of remap_pfn_range.
This is good for Xen which reuses i386/pci/i386.c for domain 0 code.
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Sanitized and fixed floppy dependencies: split the messy dependencies for
BLK_DEV_FD by introducing a new symbol (ARCH_MAY_HAVE_PC_FDC), making
BLK_DEV_FD depend on that one and taking declarations of ARCH_MAY_HAVE_PC_FDC
to arch/*/Kconfig. While we are at it, fixed several obvious cases when
BLK_DEV_FD should have been excluded (architectures lacking asm/floppy.h
are *not* going to have floppy.c compile, let alone work).
If you can come up with better name for that ("this architecture might
have working PC-compatible floppy disk controller"), you are more than
welcome - just s/ARCH_MAY_HAVE_PC_FDC/your_prefered_name/g in the patch
below...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch fixes a race condition where in system used to hang or sometime
crash within minutes when kprobes are inserted on ISR routine and a task
routine.
The fix has been stress tested on i386, ia64, pp64 and on x86_64. To
reproduce the problem insert kprobes on schedule() and do_IRQ() functions
and you should see hang or system crash.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch fixes a bug in kprobes's handling of a corner case on i386 and
x86_64. On an SMP system, if one CPU unregisters a kprobe just after
another CPU hits that probepoint, kprobe_handler() on the latter CPU sees
that the kprobe has been unregistered, and attempts to let the CPU continue
as if the probepoint hadn't been hit. The bug is that on i386 and x86_64,
we were neglecting to set the IP back to the beginning of the probed
instruction. This could cause an oops or crash.
This bug doesn't exist on ppc64 and ia64, where a breakpoint instruction
leaves the IP pointing to the beginning of the instruction. I don't know
about sparc64. (Dave, could you please advise?)
This fix has been tested on i386 and x86_64 SMP systems. To reproduce the
problem, set one CPU to work registering and unregistering a kprobe
repeatedly, and another CPU pounding the probepoint in a tight loop.
Acked-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch contains the i386 architecture specific changes to prevent the
possible race conditions.
Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Background:
1) dmi_check_system() returns the count of the number of
matches. Zero thus means no matches.
2) A match callback can return nonzero to stop the match
checking.
Bug: The count is incremented after we check for the nonzero return value,
so it does not reflect the actual count. We could say this is intended,
for some dumb reason, except that it means that a match on the first check
returns zero--no matches--if the callback returns nonzero.
Attached patch implements the count before calling the callback and thus
before potentially short-circuiting.
Signed-off-by: Robert Love <rml@novell.com>
Cc: Andrey Panin <pazke@donpac.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds onboard devices and IPMI BMC discovery into DMI scan code.
Drivers can use dmi_find_device() function to search for devices by type and
name.
Signed-off-by: Andrey Panin <pazke@donpac.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch changes dmi_string() function to allocate string copy by itself, to
avoid code duplication in the next patch.
Signed-off-by: Andrey Panin <pazke@donpac.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
DMI debugging code is unused for ages. This patch removes it.
Signed-off-by: Andrey Panin <pazke@donpac.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
After elimination of central DMI blacklist dmi_scan_machine() function became
a wrapper for dmi_iterate(). This patch moves some code around to kill
unneeded function.
Signed-off-by: Andrey Panin <pazke@donpac.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch cleans up a commonly repeated set of changes to the NTP state
variables by adding two helper inline functions:
ntp_clear(): Clears the ntp state variables
ntp_synced(): Returns 1 if the system is synced with a time server.
This was compile tested for alpha, arm, i386, x86-64, ppc64, s390, sparc,
sparc64.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Mark variables which are usually accessed for reads with __readmostly.
Signed-off-by: Alok N Kataria <alokk@calsoftinc.com>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The second arg of do_timer_interrupt() is not used in the functions, and
all callers pass NULL.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Paul Mundt <lethal@Linux-SH.ORG>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The i386 OProfile code has a function named nmi_exit(), which collides with
the nmi_exit() macro in linux/hardirq.h. At the moment, we get away with
it, because hardirq.h isn't included in the oprofile code. I hit this as a
bug when working with a patch which (indirectly) adds a #include of
hardirq.h to oprofile.
Regardless, the name collision is probably not a good idea, so this patch
fixes it, renaming the oprofile function to op_nmi_exit(). It also renames
the nmi_init() and nmi_timer_init() functions similarly, for consistency.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Frank Sorenson <frank@tuxrocks.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Uses of RCU for dynamically changeable NMI handlers need to use the new
rcu_dereference() and rcu_assign_pointer() facilities. This change makes
it clear that these uses are safe from a memory-barrier viewpoint, but the
main purpose is to document exactly what operations are being protected by
RCU. This has been tested on x86 and x86-64, which are the only
architectures affected by this change.
Signed-off-by: <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Move some more frequently read variables that showed up during some of our
performance tests as sometimes ending up in hot cachelines to the
read_mostly section.
Fix: Move the __read_mostly from before hpet_usec_quotient to follow the
variable like the other uses of __read_mostly.
Signed-off-by: Alok N Kataria <alokk@calsoftinc.com>
Signed-off-by: Christoph Lameter <christoph@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds a new kernel debug feature: CONFIG_DETECT_SOFTLOCKUP.
When enabled then per-CPU watchdog threads are started, which try to run
once per second. If they get delayed for more than 10 seconds then a
callback from the timer interrupt detects this condition and prints out a
warning message and a stack dump (once per lockup incident). The feature
is otherwise non-intrusive, it doesnt try to unlock the box in any way, it
only gets the debug info out, automatically, and on all CPUs affected by
the lockup.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-Off-By: Matthias Urlichs <smurf@smurf.noris.de>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Need to create sysfs only for cpus that are present. Without which we see
NR_CPUS entries created when we have CONFIG_HOTPLUG and CONFIG_HOTPLUG_CPU
enabled.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Acked-by: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When handling writes to /proc/irq, current code is re-programming rte
entries directly. This is not recommended and could potentially cause
chipset's to lockup, or cause missing interrupts.
CONFIG_IRQ_BALANCE does this correctly, where it re-programs only when the
interrupt is pending. The same needs to be done for /proc/irq handling as well.
Otherwise user space irq balancers are really not doing the right thing.
- Changed pending_irq_balance_cpumask to pending_irq_migrate_cpumask for
lack of a generic name.
- added move_irq out of IRQ_BALANCE, and added this same to X86_64
- Added new proc handler for write, so we can do deferred write at irq
handling time.
- Display of /proc/irq/XX/smp_affinity used to display CPU_MASKALL, instead
it now shows only active cpu masks, or exactly what was set.
- Provided a common move_irq implementation, instead of duplicating
when using generic irq framework.
Tested on i386/x86_64 and ia64 with CONFIG_PCI_MSI turned on and off.
Tested UP builds as well.
MSI testing: tbd: I have cards, need to look for a x-over cable, although I
did test an earlier version of this patch. Will test in a couple days.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Acked-by: Zwane Mwaikambo <zwane@holomorphy.com>
Grudgingly-acked-by: Andi Kleen <ak@muc.de>
Signed-off-by: Coywolf Qi Hunt <coywolf@lovecn.org>
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
As a follow-up to "UML Support - Ptrace: adds the host SYSEMU support, for
UML and general usage" (i.e. uml-support-* in current mm).
Avoid unconditionally jumping to work_pending and code copying, just reuse
the already existing resume_userspace path.
One interesting note, from Charles P. Wright, suggested that the API is
improvable with no downsides for UML (except that it will have to support
yet another host API, since dropping support for the current API, for UML,
is not reasonable from users' point of view).
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
CC: Charles P. Wright <cwright@cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
This is simply an adjustment for "Ptrace - i386: fix Syscall Audit interaction
with singlestep" to work on top of SYSEMU patches, too. On this patch, I have
some doubts: I wonder why we need to alter that way ptrace_disable().
I left the patch this way because it has been extensively tested, but I don't
understand the reason.
The current PTRACE_DETACH handling simply clears child->ptrace; actually this
is not enough because entry.S just looks at the thread_flags; actually,
do_syscall_trace checks current->ptrace but I don't think depending on that is
good, at least for performance, so I think the clearing is done elsewhere.
For instance, on PTRACE_CONT it's done, but doing PTRACE_DETACH without
PTRACE_CONT is possible (and happens when gdb crashes and one kills it
manually).
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
CC: Roland McGrath <roland@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch implements the new ptrace option PTRACE_SYSEMU_SINGLESTEP, which
can be used by UML to singlestep a process: it will receive SINGLESTEP
interceptions for normal instructions and syscalls, but syscall execution will
be skipped just like with PTRACE_SYSEMU.
Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With this patch, we change the way we handle switching from PTRACE_SYSEMU to
PTRACE_{SINGLESTEP,SYSCALL}, to free TIF_SYSCALL_EMU from double use as a
preparation for PTRACE_SYSEMU_SINGLESTEP extension, without changing the
behavior of the host kernel.
Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Jeff Dike <jdike@addtoit.com>,
Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>,
Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Adds a new ptrace(2) mode, called PTRACE_SYSEMU, resembling PTRACE_SYSCALL
except that the kernel does not execute the requested syscall; this is useful
to improve performance for virtual environments, like UML, which want to run
the syscall on their own.
In fact, using PTRACE_SYSCALL means stopping child execution twice, on entry
and on exit, and each time you also have two context switches; with SYSEMU you
avoid the 2nd stop and so save two context switches per syscall.
Also, some architectures don't have support in the host for changing the
syscall number via ptrace(), which is currently needed to skip syscall
execution (UML turns any syscall into getpid() to avoid it being executed on
the host). Fixing that is hard, while SYSEMU is easier to implement.
* This version of the patch includes some suggestions of Jeff Dike to avoid
adding any instructions to the syscall fast path, plus some other little
changes, by myself, to make it work even when the syscall is executed with
SYSENTER (but I'm unsure about them). It has been widely tested for quite a
lot of time.
* Various fixed were included to handle the various switches between
various states, i.e. when for instance a syscall entry is traced with one of
PT_SYSCALL / _SYSEMU / _SINGLESTEP and another one is used on exit.
Basically, this is done by remembering which one of them was used even after
the call to ptrace_notify().
* We're combining TIF_SYSCALL_EMU with TIF_SYSCALL_TRACE or TIF_SINGLESTEP
to make do_syscall_trace() notice that the current syscall was started with
SYSEMU on entry, so that no notification ought to be done in the exit path;
this is a bit of a hack, so this problem is solved in another way in next
patches.
* Also, the effects of the patch:
"Ptrace - i386: fix Syscall Audit interaction with singlestep"
are cancelled; they are restored back in the last patch of this series.
Detailed descriptions of the patches doing this kind of processing follow (but
I've already summed everything up).
* Fix behaviour when changing interception kind #1.
In do_syscall_trace(), we check the status of the TIF_SYSCALL_EMU flag
only after doing the debugger notification; but the debugger might have
changed the status of this flag because he continued execution with
PTRACE_SYSCALL, so this is wrong. This patch fixes it by saving the flag
status before calling ptrace_notify().
* Fix behaviour when changing interception kind #2:
avoid intercepting syscall on return when using SYSCALL again.
A guest process switching from using PTRACE_SYSEMU to PTRACE_SYSCALL
crashes.
The problem is in arch/i386/kernel/entry.S. The current SYSEMU patch
inhibits the syscall-handler to be called, but does not prevent
do_syscall_trace() to be called after this for syscall completion
interception.
The appended patch fixes this. It reuses the flag TIF_SYSCALL_EMU to
remember "we come from PTRACE_SYSEMU and now are in PTRACE_SYSCALL", since
the flag is unused in the depicted situation.
* Fix behaviour when changing interception kind #3:
avoid intercepting syscall on return when using SINGLESTEP.
When testing 2.6.9 and the skas3.v6 patch, with my latest patch and had
problems with singlestepping on UML in SKAS with SYSEMU. It looped
receiving SIGTRAPs without moving forward. EIP of the traced process was
the same for all SIGTRAPs.
What's missing is to handle switching from PTRACE_SYSCALL_EMU to
PTRACE_SINGLESTEP in a way very similar to what is done for the change from
PTRACE_SYSCALL_EMU to PTRACE_SYSCALL_TRACE.
I.e., after calling ptrace(PTRACE_SYSEMU), on the return path, the debugger is
notified and then wake ups the process; the syscall is executed (or skipped,
when do_syscall_trace() returns 0, i.e. when using PTRACE_SYSEMU), and
do_syscall_trace() is called again. Since we are on the return path of a
SYSEMU'd syscall, if the wake up is performed through ptrace(PTRACE_SYSCALL),
we must still avoid notifying the parent of the syscall exit. Now, this
behaviour is extended even to resuming with PTRACE_SINGLESTEP.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Avoid giving two traps for singlestep instead of one, when syscall auditing is
enabled.
In fact no singlestep trap is sent on syscall entry, only on syscall exit, as
can be seen in entry.S:
# Note that in this mask _TIF_SINGLESTEP is not tested !!! <<<<<<<<<<<<<<
testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP),TI_flags(%ebp)
jnz syscall_trace_entry
...
syscall_trace_entry:
...
call do_syscall_trace
But auditing a SINGLESTEP'ed process causes do_syscall_trace to be called, so
the tracer will get one more trap on the syscall entry path, which it
shouldn't.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
CC: Roland McGrath <roland@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Linus Torvalds