sync_tsc was using smp_call_function to ask the boot processor to report
it's tsc value. smp_call_function performs an IPI_send_allbutself which is
a broadcast ipi. There is a window during processor startup during which
the target cpu has started and before it has initialized it's interrupt
vectors so it can properly process an interrupt. Receveing an interrupt
during that window will triple fault the cpu and do other nasty things.
Why cli does not protect us from that is beyond me.
The simple fix is to match ia64 and provide a smp_call_function_single.
Which avoids the broadcast and is more efficient.
This certainly fixes the problem of getting stuck on boot which was
very easy to trigger on my SMP Hyperthreaded Xeon, and I think
it fixes it for the right reasons.
Minor changes by AK
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use the standard hardware page table manipulation macros.
This is possible now that linux works with all 4 levels
of the page tables.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Some edge problems with the original C rewrite.
Thanks go to Cal Peake, who pinpointed the breakage to the rewrite, and
tested this fixed version.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We added an include of asm/vm86.h in include/asm-i386/ptrace.h. Since UML
includes the underlying arch's ptrace.h, it needs an asm/vm86.h in order to
build.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch eliminates the GCC4 warning on the x86_64 platform:
kernel/sched.c:1824: warning: control may reach end of non-void function
'sched_find_first_bit' being inlined.
The change follows the lead of others, i.e. it is guaranteed that at least
one of b[0], b[1], or b[2] will have a bit set and evaluate to true. That
being said, GCC4.0.0 notices that the code flow does not return anything if
b[0], b[1] and b[2] are not true. Since we know better, if it's not b[0] or
b[1], it has to be b[2].
Signed-off-by: Jesse Millan <jessem@cs.pdx.edu>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This avoids some potential stack overflows with very deep softirq callchains.
i386 does this too.
TOADD CFI annotation
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This avoids confusing the disassembler. Costs 2 bytes per BUG.
Thanks to Suresh Siddha and Jan Beulich for suggesting suitable instructions.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Harmless because the kernel didn't use it. Noticed by Travis Betak
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Were either outdated or misleading.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Minor cleanup.
Move things into their include files, remove obsolete includes, fix
indentation, remove obsolete special cases etc.
I also added the per cpu section to asm-generic/sections.h and fixed
init/main.c to use it.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Makes it slightly more efficient.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
build warning: discards qualifiers from pointer target type
when mixing "const char *" and "char *"
We should probably update the routines to expect const,
but easier for now to shut up the warning with 1 cast.
Signed-off-by: Len Brown <len.brown@intel.com>
We sometimes forgot to check whether the exclusive store succeeded.
Ensure that we always check. Also ensure that we always use the
out of line versions, since the inline versions are not SMP safe.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
It may shut up gcc, but it also incorrectly changes the semantics of the
smp_call_function() helpers.
You can fix the warning other ways if you are interested (create another
inline function that takes no arguments and returns zero), but
preferably gcc just shouldn't complain about unused return values from
statement expressions in the first place.
Avoid using "rep scas", just let the compiler select a sequence of
regular instructions.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Apparently gcc 4.0 complains about "({ 0; });", which leads to -Werror
breakage in one of the alpha oprofile modules.
One might could argue that this is a gcc bug, in that statement-expressions
should be considered to be function-like rather than statement-like for the
purposes of this warning. But it's just as easy to use an inline function
in the first place, side-stepping the issue.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
