Move X86_32 only get_segment_eip to X86_64
Move X86_64 only is_errata93 to X86_32
Change X86_32 loop in is_prefetch to highlight the differences
between them. Fold the logic from __is_prefetch in as well on
X86_32.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When developing the Kprobes arch code for ARM, I ran across some code
found in x86 and s390 Kprobes arch code which I didn't consider as
good as it could be.
Once I figured out what the code was doing, I changed the code
for ARM Kprobes to work the way I felt was more appropriate.
I've tested the code this way in ARM for about a year and would
like to push the same change to the other affected architectures.
The code in question is in kprobe_exceptions_notify() which
does:
====
/* kprobe_running() needs smp_processor_id() */
preempt_disable();
if (kprobe_running() &&
kprobe_fault_handler(args->regs, args->trapnr))
ret = NOTIFY_STOP;
preempt_enable();
====
For the moment, ignore the code having the preempt_disable()/
preempt_enable() pair in it.
The problem is that kprobe_running() needs to call smp_processor_id()
which will assert if preemption is enabled. That sanity check by
smp_processor_id() makes perfect sense since calling it with preemption
enabled would return an unreliable result.
But the function kprobe_exceptions_notify() can be called from a
context where preemption could be enabled. If that happens, the
assertion in smp_processor_id() happens and we're dead. So what
the original author did (speculation on my part!) is put in the
preempt_disable()/preempt_enable() pair to simply defeat the check.
Once I figured out what was going on, I considered this an
inappropriate approach. If kprobe_exceptions_notify() is called
from a preemptible context, we can't be in a kprobe processing
context at that time anyways since kprobes requires preemption to
already be disabled, so just check for preemption enabled, and if
so, blow out before ever calling kprobe_running(). I wrote the ARM
kprobe code like this:
====
/* To be potentially processing a kprobe fault and to
* trust the result from kprobe_running(), we have
* be non-preemptible. */
if (!preemptible() && kprobe_running() &&
kprobe_fault_handler(args->regs, args->trapnr))
ret = NOTIFY_STOP;
====
The above code has been working fine for ARM Kprobes for a year.
So I changed the x86 code (2.6.24-rc6) to be the same way and ran
the Systemtap tests on that kernel. As on ARM, Systemtap on x86
comes up with the same test results either way, so it's a neutral
external functional change (as expected).
This issue has been discussed previously on linux-arm-kernel and the
Systemtap mailing lists. Pointers to the by base for the two
discussions:
http://lists.arm.linux.org.uk/lurker/message/20071219.223225.1f5c2a5e.en.htmlhttp://sourceware.org/ml/systemtap/2007-q1/msg00251.html
Signed-off-by: Quentin Barnes <qbarnes@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Ananth N Mavinakayahanalli <ananth@in.ibm.com>
Acked-by: Ananth N Mavinakayahanalli <ananth@in.ibm.com>
This patch eliminates most of code-style errors
discovered by checkpatch.pl on arch/x86/kernel/apm_32.c
no code changed:
text data bss dec hex filename
12142 1837 84 14063 36ef apm_32.o.before
12142 1837 84 14063 36ef apm_32.o.after
md5:
2676b881ad55e387da4a995e8b9ee372 apm_32.o.before.asm
2676b881ad55e387da4a995e8b9ee372 apm_32.o.after.asm
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
PCI is one of the few hardware stuff where defaulting to y makes sense.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
H. Peter Anvin <hpa@zytor.com> wrote:
> It probably should actually HLT, to avoid sucking power, and stressing
> the thermal system. We're dead at this point, and the early 486's
> which had problems with HLT will lock up - we don't care.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
CONFIG_X86_PPRO_FENCE bloats text:
i386 allmodconf: size mm/built-in.o
text data bss dec hex text ratio
vanilla: 163082 20372 40120 223574 36956 100.00%
bugfix : 163509 20372 40120 224001 36b01 0.26%
noppro : 162191 20372 40120 222683 365db - 0.55%
both : 162267 20372 40120 222759 36627 - 0.50% (+0.05% vs noppro)
So with the ppro memory ordering bug out of the way, the PG_uptodate fix
only adds 76 bytes of text.
allow this config to be specified by distros.
[ mingo@elte.hu: x86.git merge ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Trivial unification of Makefiles for the
x86 specific library part.
Linking order is slightly modified but should be harmless.
Tested doing a defconfig build before and after and saw
no build changes.
It adds almost as many lines as it deletes - bacause
I broke a few lines up fo readability in the Makefile.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Trivial unification of the two Makefiles.
Tested doing a defconfig build for both 32 and 64 bit and
no build changes occured.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Combine the 32 and 64 bit specific Makefiles in one file.
While doing so link order was (almost) preserved on 32 bit
but on 64 bit link order changed a lot.
Patch was checked with defconfig + allyesconfig builds.
The same .o files were linked in these configurations.
To keep readability of the Makefiles a few Kconfig
symbols was added/modified and it was checked that
they were not used anywhere else.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
A few files remained after 'make clean' in arch/x86/vdso/.
Teach vdso to clean up those files in a bit brutal fashion.
The filenames are just hardcoded in the Makefile.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
There were no reason to mess around with CC, AS and LD.
Fixing this up avoided duplicated option for ld.
A small fixlet were needed in boot/Makefile which assumed
that CC were modified.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
On recommendation from Andi Kleen share a few more options
between 32 and 64 bit builds.
A defconfig build for i386 did not show any difference in
size of text and data.
The additional shared options are:
-Wno-sign-compare
-fno-asynchronous-unwind-tables
-mno-sse
-mno-mmx
-mno-sse2
-mno-3dnow
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Unify the 32 and 64 bit specific Makefiles.
The unification was simplest to do in one step although the
readability of the patch suffers a bit from this.
Noteworthy remarks on the unification:
- The 64 bit cpu stuff should be moved to Makefile_32.cpu
but I did not feel confident doing it due to subtle differences
- The use of cflags-y were abandoned since we have seen one bug where
we did wrong due to missing assignment to KBUILD_CFLAGS.
The cc-option marcro uses KBUILD_CFLAGS.
- The "No need to remake" line are deleted. It caused "make -B" to fail
- For 64 bit the sub architecture stuff is not used.
- The way head64.o is specified could be nicer - but it awaits the
introduction of head32.o (which seems like a win to introduce for readability)
- Patch is checkpatch clean
Patch is tested by doing a defconfig build for i386 and x86_64 and in both
cases monitoring that only relevant files were recompiled when applying
the patch.
[ mingo@elte.hu: build fix ]
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Make the control flow of kprobe_handler more obvious.
Collapse the separate if blocks/gotos with if/else blocks
this unifies the duplication of the check for a breakpoint
instruction race with another cpu.
Create two jump targets:
preempt_out: re-enables preemption before returning ret
out: only returns ret
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
First step towards unifying these files.
- Checkpatch trailing whitespace fixes
- Checkpatch indentation of switch statement fixes
- Checkpatch single statement ifs need no braces fixes
- Checkpatch consistent spacing after comma fixes
- Introduce defines for pagefault error bits from X86_64 and add useful
comment from X86_32. Use these defines in X86_32 where obvious.
- Unify comments between 32|64 bit
- Small ifdef movement for CONFIG_KPROBES in notify_page_fault()
- Introduce X86_64 only case statement
No Functional Changes.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The functions time_before, time_before_eq, time_after, and time_after_eq
are more robust for comparing jiffies against other values.
A simplified version of the semantic patch making this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@ change_compare_np @
expression E;
@@
(
- jiffies <= E
+ time_before_eq(jiffies,E)
|
- jiffies >= E
+ time_after_eq(jiffies,E)
|
- jiffies < E
+ time_before(jiffies,E)
|
- jiffies > E
+ time_after(jiffies,E)
)
@ include depends on change_compare_np @
@@
#include <linux/jiffies.h>
@ no_include depends on !include && change_compare_np @
@@
#include <linux/...>
+ #include <linux/jiffies.h>
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The functions time_before, time_before_eq, time_after, and time_after_eq
are more robust for comparing jiffies against other values.
A simplified version of the semantic patch making this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@ change_compare_np @
expression E;
@@
(
- jiffies <= E
+ time_before_eq(jiffies,E)
|
- jiffies >= E
+ time_after_eq(jiffies,E)
|
- jiffies < E
+ time_before(jiffies,E)
|
- jiffies > E
+ time_after(jiffies,E)
)
@ include depends on change_compare_np @
@@
#include <linux/jiffies.h>
@ no_include depends on !include && change_compare_np @
@@
#include <linux/...>
+ #include <linux/jiffies.h>
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The functions time_before, time_before_eq, time_after, and time_after_eq
are more robust for comparing jiffies against other values.
A simplified version of the semantic patch making this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@ change_compare_np @
expression E;
@@
(
- jiffies <= E
+ time_before_eq(jiffies,E)
|
- jiffies >= E
+ time_after_eq(jiffies,E)
|
- jiffies < E
+ time_before(jiffies,E)
|
- jiffies > E
+ time_after(jiffies,E)
)
@ include depends on change_compare_np @
@@
#include <linux/jiffies.h>
@ no_include depends on !include && change_compare_np @
@@
#include <linux/...>
+ #include <linux/jiffies.h>
// </smpl>
[ mingo@elte.hu: merge to x86.git ]
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Move #ifdef around function definiton into the function and
unconditionally return on X86_32. Saves an ifdef from the
one callsite.
[ mingo@elte.hu: minor cleanup. ]
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
