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2009-09-24powerpc: Move 64bit heap above 1TB on machines with 1TB segmentsAnton Blanchard
If we are using 1TB segments and we are allowed to randomise the heap, we can put it above 1TB so it is backed by a 1TB segment. Otherwise the heap will be in the bottom 1TB which always uses 256MB segments and this may result in a performance penalty. This functionality is disabled when heap randomisation is turned off: echo 1 > /proc/sys/kernel/randomize_va_space which may be useful when trying to allocate the maximum amount of 16M or 16G pages. On a microbenchmark that repeatedly touches 32GB of memory with a stride of 256MB + 4kB (designed to stress 256MB segments while still mapping nicely into the L1 cache), we see the improvement: Force malloc to use heap all the time: # export MALLOC_MMAP_MAX_=0 MALLOC_TRIM_THRESHOLD_=-1 Disable heap randomization: # echo 1 > /proc/sys/kernel/randomize_va_space # time ./test 12.51s Enable heap randomization: # echo 2 > /proc/sys/kernel/randomize_va_space # time ./test 1.70s Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-09-11powerpc/booke: Don't set DABR on 64-bit BookE, use DAC1 insteadBenjamin Herrenschmidt
Also remove a duplicate setting of it in the context switch path on BookE. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-08-20powerpc: Clean ifdef usage in copy_thread()Benjamin Herrenschmidt
Currently, a single ifdef covers SLB related bits and more generic ppc64 related bits, split this in two separate ifdef's since 64-bit BookE will need one but not the other. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-06-26powerpc: Fix output from show_regsKumar Gala
For some reason we've had an explicit KERN_INFO for GPR dumps. With recent changes we get output like: <6>GPR00: 00000000 ef855eb0 ef858000 00000001 000000d0 f1000000 ffbc8000 ffffffff The KERN_INFO is causing the <6>. Don't see any reason to keep it around. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-06-09powerpc: Shield code specific to 64-bit server processorsBenjamin Herrenschmidt
This is a random collection of added ifdef's around portions of code that only mak sense on server processors. Using either CONFIG_PPC_STD_MMU_64 or CONFIG_PPC_BOOK3S as seems appropriate. This is meant to make the future merging of Book3E 64-bit support easier. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-04-02Simplify copy_thread()Alexey Dobriyan
First argument unused since 2.3.11. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-23powerpc: Randomise PIEsAnton Blanchard
Randomise ELF_ET_DYN_BASE, which is used when loading position independent executables. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-23powerpc: Randomise the brk regionAnton Blanchard
Randomize the heap. before: tundro2:~ # sleep 1 & cat /proc/${!}/maps | grep heap 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] after tundro2:~ # sleep 1 & cat /proc/${!}/maps | grep heap 19419000-1951a000 rw-p 19419000 00:00 0 [heap] 325ff000-32700000 rw-p 325ff000 00:00 0 [heap] 1a97c000-1aa7d000 rw-p 1a97c000 00:00 0 [heap] 1cc60000-1cd61000 rw-p 1cc60000 00:00 0 [heap] 1afa9000-1b0aa000 rw-p 1afa9000 00:00 0 [heap] Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-23powerpc: Randomise lower bits of stack addressAnton Blanchard
Randomise the lower bits of the stack address. More randomisation is good for security but the scatter can also help with SMT threads that share an L1. A quick test case shows this working: int main() { int sp; printf("%x\n", (unsigned long)&sp & 4095); } before: 80 80 80 80 80 after: 610 490 300 6b0 d80 Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-23powerpc64: port of the function graph tracerSteven Rostedt
This is a port of the function graph tracer that was written by Frederic Weisbecker for the x86. This only works for PPC64 at the moment and only for static tracing. PPC32 and dynamic function graph tracing support will come later. The trace produces a visual calling of functions: # tracer: function_graph # # CPU DURATION FUNCTION CALLS # | | | | | | | 0) 2.224 us | } 0) ! 271.024 us | } 0) ! 320.080 us | } 0) ! 324.656 us | } 0) ! 329.136 us | } 0) | .put_prev_task_fair() { 0) | .update_curr() { 0) 2.240 us | .update_min_vruntime(); 0) 6.512 us | } 0) 2.528 us | .__enqueue_entity(); 0) + 15.536 us | } 0) | .pick_next_task_fair() { 0) 2.032 us | .__pick_next_entity(); 0) 2.064 us | .__clear_buddies(); 0) | .set_next_entity() { 0) 2.672 us | .__dequeue_entity(); 0) 6.864 us | } Geoff Lavand tested on PS3. Tested-by: Geoff Levand <geoffrey.levand@am.sony.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-12-31[PATCH] idle cputime accountingMartin Schwidefsky
The cpu time spent by the idle process actually doing something is currently accounted as idle time. This is plain wrong, the architectures that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the time spent doing nothing and the time spent by idle doing work. The first is accounted with account_idle_time and the second with account_system_time. The architectures that use the account_xxx_time interface directly and not the account_xxx_ticks interface now need to do the check for the idle process in their arch code. In particular to improve the system vs true idle time accounting the arch code needs to measure the true idle time instead of just testing for the idle process. To improve the tick based accounting as well we would need an architecture primitive that can tell us if the pt_regs of the interrupted context points to the magic instruction that halts the cpu. In addition idle time is no more added to the stime of the idle process. This field now contains the system time of the idle process as it should be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as every tick that occurs while idle is running will be accounted as idle time. This patch contains the necessary common code changes to be able to distinguish idle system time and true idle time. The architectures with support for VIRT_CPU_ACCOUNTING need some changes to exploit this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-03powerpc: Allow the max stack trace depth to be configuredJohannes Berg
On my screen, when something crashes, I only have space for maybe 16 functions of the stack trace before the information above it scrolls off the screen. It's easy to hack the kernel to print out only that much, but it's harder to remember to do it. This introduces a config option for it so that I can keep the setting in my config. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-12-03powerpc: Add MSR[CE, DE] to the MSR bits we print on show_regs()Kumar Gala
Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-08-04powerpc: Remove use of CONFIG_PPC_MERGEKumar Gala
Now that arch/ppc is gone and CONFIG_PPC_MERGE is always set, remove the dead code associated with !CONFIG_PPC_MERGE from arch/powerpc and include/asm-powerpc. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-28powerpc/booke: Clean up the hardware watchpoint supportKumar Gala
* CONFIG_BOOKE is selected by CONFIG_44x so we dont need both * Fixed a few comments * Go back to only using DBCR0_IDM to determine if we are using debug resources. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-25powerpc: BookE hardware watchpoint supportLuis Machado
This patch implements support for HW based watchpoint via the DBSR_DAC (Data Address Compare) facility of the BookE processors. It does so by interfacing with the existing DABR breakpoint code and adding the necessary bits and pieces for the new bits to be properly set or cleared Signed-off-by: Luis Machado <luisgpm@br.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-15powerpc: fix giveup_vsx to save registers correctlyMichael Neuling
giveup_vsx didn't save the FPU and VMX regsiters. Change it to be like giveup_fpr/altivec which save these registers. Also update call sites where FPU and VMX are already saved to use the original giveup_vsx (renamed to __giveup_vsx). Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-09powerpc: Use new printk extension %pS to print symbols on oopsBenjamin Herrenschmidt
This changes the oops and backtrace code to use the new %pS printk extension to print out symbols rather than manually calling print_symbol. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-03powerpc: Remove old dump_task_* functionsMichael Neuling
Since Roland's ptrace cleanup starting with commit f65255e8d51ecbc6c9eef20d39e0377d19b658ca ("[POWERPC] Use user_regset accessors for FP regs"), the dump_task_* functions are no longer being used. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-01powerpc: Update for VSX core file and ptraceMichael Neuling
This correctly hooks the VSX dump into Roland McGrath core file infrastructure. It adds the VSX dump information as an additional elf note in the core file (after talking more to the tool chain/gdb guys). This also ensures the formats are consistent between signals, ptrace and core files. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-01powerpc: Add VSX context save/restore, ptrace and signal supportMichael Neuling
This patch extends the floating point save and restore code to use the VSX load/stores when VSX is available. This will make FP context save/restore marginally slower on FP only code, when VSX is available, as it has to load/store 128bits rather than just 64bits. Mixing FP, VMX and VSX code will get constant architected state. The signals interface is extended to enable access to VSR 0-31 doubleword 1 after discussions with tool chain maintainers. Backward compatibility is maintained. The ptrace interface is also extended to allow access to VSR 0-31 full registers. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-01powerpc: Add macros to access floating point registers in thread_struct.Michael Neuling
We are going to change where the floating point registers are stored in the thread_struct, so in preparation add some macros to access the floating point registers. Update all code to use these new macros. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-29[POWERPC] Add IRQSTACKS support on ppc32Kumar Gala
This makes it possible to use separate stacks for hard and soft IRQs on 32-bit powerpc as well as on 64-bit. The code for 32-bit is just the 32-bit analog of the 64-bit code. * Added allocation and initialization of the irq stacks. We limit the stacks to be in lowmem for ppc32. * Implemented ppc32 versions of call_do_softirq() and call_handle_irq() to switch the stack pointers * Reworked how we do stack overflow detection. We now keep around the limit of the stack in the thread_struct and compare against the limit to see if we've overflowed. We can now use this on ppc64 if desired. [ paulus@samba.org: Fixed bug on 6xx where we need to reload r9 with the thread_info pointer. ] Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-24[POWERPC] Fix kernel stack allocation alignmentBenjamin Herrenschmidt
The powerpc kernel stacks need to be naturally aligned, as they contain the thread info at the bottom, which is obtained by clearing the low bits of the stack pointer. However, when using 64K pages, the stack is smaller than a page, so we use kmalloc to allocate it, but that doesn't provide the alignment guarantee we need. It appeared to work so far... until one enables SLUB debugging which then returns unaligned pointers. Ooops... This fixes it by using a slab cache with enforced alignment. It relies on my previous patch that adds a thread_info_cache_init() callback. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-18[POWERPC] Move stackframe definitions to common headerBenjamin Herrenschmidt
This moves various definitions used all over the place to parse stack frames to ptrace.h so only one definition is needed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-14Merge branch 'linux-2.6'Paul Mackerras
2008-03-28[POWERPC] Fix missed hardware breakpoints across multiple threadsMichael Ellerman
There is a bug in the powerpc DABR (data access breakpoint) handling, which can result in us missing breakpoints if several threads are trying to break on the same address. The circumstances are that do_page_fault() calls do_dabr(), this clears the DABR (sets it to 0) and sets up the signal which will report to userspace that the DABR was hit. The do_signal() code will restore the DABR value on the way out to userspace. If we reschedule before calling do_signal(), __switch_to() will check the cached DABR value and compare it to the new thread's value, if they match we don't set the DABR in hardware. So if two threads have the same DABR value, and we schedule from one to the other after taking the interrupt for the first thread hitting the DABR, the second thread will run without the DABR set in hardware. The cleanest fix is to move the cache update into set_dabr(), that way we can't forget to do it. Reported-by: Jan Kratochvil <jan.kratochvil@redhat.com> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-03-26Merge branch 'linux-2.6'Paul Mackerras
2008-03-26[POWERPC] Don't touch PT_DTRACE in execRoland McGrath
The PT_DTRACE flag is meaningless and obsolete. Don't touch it. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-03-20[POWERPC] Fix PMU + soft interrupt disable bugAnton Blanchard
Since the PMU is an NMI now, it can come at any time we are only soft disabled. We must hard disable around the two places we allow the kernel stack SLB and r1 to go out of sync. Otherwise the PMU exception can force a kernel stack SLB into another slot, which can lead to it getting evicted, which can lead to a nasty unrecoverable SLB miss in the exception entry code. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-02-14[POWERPC] Fix DEBUG_PREEMPT warning when warningHugh Dickins
The powerpc show_regs prints CPU using smp_processor_id: change that to raw_smp_processor_id, so that when it's showing a WARN_ON backtrace without preemption disabled, DEBUG_PREEMPT doesn't mess up that warning with its own. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-12-06[POWERPC] Fix hardware IRQ time accounting problem.Tony Breeds
The commit fa13a5a1f25f671d084d8884be96fc48d9b68275 (sched: restore deterministic CPU accounting on powerpc), unconditionally calls update_process_tick() in system context. In the deterministic accounting case this is the correct thing to do. However, in the non-deterministic accounting case we need to not do this, since doing this results in the time accounted as hardware irq time being artificially elevated. Also this collapses 2 consecutive '#ifdef CONFIG_VIRT_CPU_ACCOUNTING' checks in time.h into one for neatness. Signed-off-by: Tony Breeds <tony@bakeyournoodle.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-11-09sched: restore deterministic CPU accounting on powerpcPaul Mackerras
Since powerpc started using CONFIG_GENERIC_CLOCKEVENTS, the deterministic CPU accounting (CONFIG_VIRT_CPU_ACCOUNTING) has been broken on powerpc, because we end up counting user time twice: once in timer_interrupt() and once in update_process_times(). This fixes the problem by pulling the code in update_process_times that updates utime and stime into a separate function called account_process_tick. If CONFIG_VIRT_CPU_ACCOUNTING is not defined, there is a version of account_process_tick in kernel/timer.c that simply accounts a whole tick to either utime or stime as before. If CONFIG_VIRT_CPU_ACCOUNTING is defined, then arch code gets to implement account_process_tick. This also lets us simplify the s390 code a bit; it means that the s390 timer interrupt can now call update_process_times even when CONFIG_VIRT_CPU_ACCOUNTING is turned on, and can just implement a suitable account_process_tick(). account_process_tick() now takes the task_struct * as an argument. Tested both with and without CONFIG_VIRT_CPU_ACCOUNTING. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-19Use helpers to obtain task pid in printks (arch code)Alexey Dobriyan
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>
2007-10-17powerpc: add Altivec/VMX state to coredumpsMark Nelson
Update dump_task_altivec() (which has so far never been put to use) so that it dumps the Altivec/VMX registers (VR[0] - VR[31], VSCR and VRSAVE) in the same format as the ptrace get_vrregs(), and add the appropriate glue typedef and #defines to make it work. A new note type of NT_PPC_VMX was chosen to be 0x100 (arbitrarily) because it allows the low range values to be used for more generic purposes and 0x100 seems an adequate starting point for PowerPC extensions. Signed-off-by: Mark Nelson <markn@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andi Kleen <ak@suse.de> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-12[POWERPC] Use 1TB segmentsPaul Mackerras
This makes the kernel use 1TB segments for all kernel mappings and for user addresses of 1TB and above, on machines which support them (currently POWER5+, POWER6 and PA6T). We detect that the machine supports 1TB segments by looking at the ibm,processor-segment-sizes property in the device tree. We don't currently use 1TB segments for user addresses < 1T, since that would effectively prevent 32-bit processes from using huge pages unless we also had a way to revert to using 256MB segments. That would be possible but would involve extra complications (such as keeping track of which segment size was used when HPTEs were inserted) and is not addressed here. Parts of this patch were originally written by Ben Herrenschmidt. Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-10-03Merge branch 'linux-2.6' into for-2.6.24Paul Mackerras
2007-10-03[POWERPC] Make instruction dumping work in real modeScott Wood
On non-book-E, exceptions execute in real mode. If a fault happens that leads to a register dump, the kernel currently prints XXXXXXXX because it doesn't realize that PC is a physical address. This patch checks whether instruction address translation is turned on, and if not converts PC into a virtual address. Signed-off-by: Scott Wood <scottwood@freescale.com> Acked-by: Kumar Gala <galak@kernel.crashing.org> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-09-25[POWERPC] Ensure FULL_REGS on execRoland McGrath
When PTRACE_O_TRACEEXEC is used, a ptrace call to fetch the registers at the PTRACE_EVENT_EXEC stop (PTRACE_PEEKUSR) will oops in CHECK_FULL_REGS. With recent versions, "gdb --args /bin/sh -c 'exec /bin/true'" and "run" at the (gdb) prompt is sufficient to produce this. I also have written an isolated test case, see https://bugzilla.redhat.com/show_bug.cgi?id=301791#c15. This change fixes the problem by clearing the low bit of pt_regs.trap in start_thread so that FULL_REGS is true again. This is correct since all of the GPRs that "full" refers to are cleared in start_thread. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-09-14[POWERPC] Add cpu feature for SPE handlingKumar Gala
Make it so that SPE support can be determined at runtime. This is similiar to how we handle AltiVec. This allows us to have SPE support built in and work on processors with and without SPE. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2007-08-28[POWERPC] Flush registers to proper task contextKumar Gala
When we flush register state for FP, Altivec, or SPE in flush_*_to_thread we need to respect the task_struct that the caller has passed to us. Most cases we are called with current, however sometimes (ptrace) we may be passed a different task_struct. This showed up when using gdbserver debugging a simple program that used floating point. When gdb tried to show the FP regs they all showed up as 0, because the child's FP registers were never properly flushed to memory. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2007-07-26[POWERPC] Fix register labels on show_regs() message for 4xx/Book-EKumar Gala
In a show_regs() message The DEAR and ESR were reported as DAR and DSISR which only exist on classic parts. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2007-06-14[POWERPC] Always apply DABR changes on context switchesBenjamin Herrenschmidt
This patch removes the #ifdef CONFIG_PPC64 around setting the DABR. The actual setting of the SPR inside of the set_dabr() function is dependent on CONFIG_PPC64 || CONFIG_6xx but you can always provide a ppc_md hook to override that. We should improve support for different HW breakpoints facilities but this is a first step. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-05-08header cleaning: don't include smp_lock.h when not usedRandy Dunlap
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>
2007-04-13[POWERPC] Make tlb flush batch use lazy MMU modeBenjamin Herrenschmidt
The current tlb flush code on powerpc 64 bits has a subtle race since we lost the page table lock due to the possible faulting in of new PTEs after a previous one has been removed but before the corresponding hash entry has been evicted, which can leads to all sort of fatal problems. This patch reworks the batch code completely. It doesn't use the mmu_gather stuff anymore. Instead, we use the lazy mmu hooks that were added by the paravirt code. They have the nice property that the enter/leave lazy mmu mode pair is always fully contained by the PTE lock for a given range of PTEs. Thus we can guarantee that all batches are flushed on a given CPU before it drops that lock. We also generalize batching for any PTE update that require a flush. Batching is now enabled on a CPU by arch_enter_lazy_mmu_mode() and disabled by arch_leave_lazy_mmu_mode(). The code epects that this is always contained within a PTE lock section so no preemption can happen and no PTE insertion in that range from another CPU. When batching is enabled on a CPU, every PTE updates that need a hash flush will use the batch for that flush. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-04-13Merge branch 'linux-2.6' into for-2.6.22Paul Mackerras
2007-03-26[POWERPC] Use lowercase for hex printouts in oops messages.anton@samba.org
Use lowercase for hex printouts in oops messages. The number of times I have tried to copy and paste from an oops into an objdump search... Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-03-22[POWERPC] Remove last_syscallAnton Blanchard
Remove last_syscall from 32bit powerpc, its been gone in 64bit for years. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-03-16[POWERPC] Fix atomicity of TIF update in flush_thread()Mathieu Desnoyers
Fix atomicity of TIF update in flush_thread() for powerpc Fixes it correctly with *_ti_thread_flag. Race : parent process executing : sys_ptrace() (lock_kernel()) (ptrace_get_task_struct(pid)) arch_ptrace() ptrace_detach() ptrace_disable(child); clear_singlestep(child); clear_tsk_thread_flag(child, TIF_SINGLESTEP); (which clears the TIF_SINGLESTEP flag atomically from a different process) (put_task_struct(child)) (unlock_kernel()) And at the same time, in the child process : sys_execve() do_execve() search_binary_handler() load_elf_binary() flush_old_exec() flush_thread() doing a non-atomic thread flag update Applies on 2.6.20. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-03-08[POWERPC] Harden validate_sp against stack corruptionPaul Mackerras
If something has overflowed or corrupted the stack and causes an oops, and we try to print a stack trace, that will call validate_sp, which can itself cause an oops if the cpu field of the thread_info struct at the bottom of the stack has been corrupted (if CONFIG_IRQSTACKS is set). This makes debugging harder. To avoid the second oops, this adds a check to make sure that the cpu number is reasonable before using it to check whether the stack is on the softirq or hardirq stack. Signed-off-by: Paul Mackerras <paulus@samba.org>