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2009-03-27powerpc: Sanitize stack pointer in signal handling codeJosh Boyer
On powerpc64 machines running 32-bit userspace, we can get garbage bits in the stack pointer passed into the kernel. Most places handle this correctly, but the signal handling code uses the passed value directly for allocating signal stack frames. This fixes the issue by introducing a get_clean_sp function that returns a sanitized stack pointer. For 32-bit tasks on a 64-bit kernel, the stack pointer is masked correctly. In all other cases, the stack pointer is simply returned. Additionally, we pass an 'is_32' parameter to get_sigframe now in order to get the properly sanitized stack. The callers are know to be 32 or 64-bit statically. Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-31powerpc: Fix swapcontext system for VSX + old ucontext sizeMichael Neuling
Since VSX support was added, we now have two sizes of ucontext_t; the older, smaller size without the extra VSX state, and the new larger size with the extra VSX state. A program using the sys_swapcontext system call and supplying smaller ucontext_t structures will currently get an EINVAL error if the task has used VSX (e.g. because of calling library code that uses VSX) and the old_ctx argument is non-NULL (i.e. the program is asking for its current context to be saved). Thus the program will start getting EINVAL errors on calls that previously worked. This commit changes this behaviour so that we don't send an EINVAL in this case. It will now return the smaller context but the VSX MSR bit will always be cleared to indicate that the ucontext_t doesn't include the extra VSX state, even if the task has executed VSX instructions. Both 32 and 64 bit cases are updated. [paulus@samba.org - also fix some access_ok() and get_user() calls] Thanks to Ben Herrenschmidt for noticing this problem. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-10-22powerpc: Remove empty #else from signal_64.cMichael Neuling
Remove empty/bogus #else from signal_64.c Signed-off-by: Michael Neuling <mikey@neuling.org> 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: fix swapcontext backwards compat. with VSX ucontext changesMichael Neuling
When the ucontext changed to add the VSX context, this broke backwards compatibly on swapcontext. swapcontext only compares the ucontext size passed in from the user to the new kernel ucontext size. This adds a check against the old ucontext size (with VMX but without VSX). It also adds some sanity check for ucontexts without VSX, but where VSX is used according the MSR. Fixes for both 32 and 64bit processes on 64bit kernels Kudos to Paulus for noticing. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-03powerpc: Clean up copy_to/from_user for vsx and fprMichael Neuling
This merges and cleans up some of the ugly copy/to from user code which is required for the new fpr and vsx layout in the thread_struct. Also fixes some hard coded buffer sizes and removes a redundant fpr_flush_to_thread. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-01powerpc: Fix compile error for CONFIG_VSXMichael Neuling
Fix compile error when CONFIG_VSX is enabled. arch/powerpc/kernel/signal_64.c: In function 'restore_sigcontext': arch/powerpc/kernel/signal_64.c:241: error: 'i' undeclared (first use in this function) Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-01powerpc: Explicitly copy elements of pt_regsStephen Rothwell
Gcc 4.3 produced this warning: arch/powerpc/kernel/signal_64.c: In function 'restore_sigcontext': arch/powerpc/kernel/signal_64.c:161: warning: array subscript is above array bounds This is caused by us copying to aliases of elements of the pt_regs structure. Make those explicit. This adds one extra __get_user and unrolls a loop. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> 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: Introduce VSX thread_struct and CONFIG_VSXMichael Neuling
The layout of the new VSR registers and how they overlap on top of the legacy FPR and VR registers is: VSR doubleword 0 VSR doubleword 1 ---------------------------------------------------------------- VSR[0] | FPR[0] | | ---------------------------------------------------------------- VSR[1] | FPR[1] | | ---------------------------------------------------------------- | ... | | | ... | | ---------------------------------------------------------------- VSR[30] | FPR[30] | | ---------------------------------------------------------------- VSR[31] | FPR[31] | | ---------------------------------------------------------------- VSR[32] | VR[0] | ---------------------------------------------------------------- VSR[33] | VR[1] | ---------------------------------------------------------------- | ... | | ... | ---------------------------------------------------------------- VSR[62] | VR[30] | ---------------------------------------------------------------- VSR[63] | VR[31] | ---------------------------------------------------------------- VSX has 64 128bit registers. The first 32 regs overlap with the FP registers and hence extend them with and additional 64 bits. The second 32 regs overlap with the VMX registers. This commit introduces the thread_struct changes required to reflect this register layout. Ptrace and signals code is updated so that the floating point registers are correctly accessed from the thread_struct when CONFIG_VSX is enabled. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-09[POWERPC] Fix incorrect enabling of VMX when building signal or user contextBenjamin Herrenschmidt
When building a signal or a ucontext, we can incorrectly set the MSR_VEC bit of the kernel pt_regs->msr before returning to userspace if the task -ever- used VMX. This can lead to funny result if that stack used it in the past, then "lost" it (ie. it wasn't enabled after a context switch for example) and then called get_context. It can end up with VMX enabled and the registers containing values from some other task. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-10-12[POWERPC] Implement logging of unhandled signalsOlof Johansson
Implement show_unhandled_signals sysctl + support to print when a process is killed due to unhandled signals just as i386 and x86_64 does. Default to having it off, unlike x86 that defaults on. Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-07-11Merge branch 'for-2.6.23' into mergePaul Mackerras
2007-06-26[POWERPC] Fix subtle FP state corruption bug in signal return on SMPPaul Mackerras
This fixes a bug which can cause corruption of the floating-point state on return from a signal handler. If we have a signal handler that has used the floating-point registers, and it happens to context-switch to another task while copying the interrupted floating-point state from the user stack into the thread struct (e.g. because of a page fault, or because it gets preempted), the context switch code will think that the FP registers contain valid FP state that needs to be copied into the thread_struct, and will thus overwrite the values that the signal return code has put into the thread_struct. This can occur because we clear the MSR bits that indicate the presence of valid FP state after copying the state into the thread_struct. To fix this we just move the clearing of the MSR bits to before the copy. A similar potential problem also occurs with the Altivec state, and this fixes that in the same way. Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-14[POWERPC] Merge creation of signal frameBenjamin Herrenschmidt
The code for creating signal frames was still duplicated and split in strange ways between 32 and 64 bits, including the SA_ONSTACK handling being in do_signal on 32 bits but inside handle_rt_signal on 64 bits etc... This moves the 64 bits get_sigframe() to the generic signal.c, cleans it a bit, moves the access_ok() call done by all callers to it as well, and adapts/cleanups the 3 different signal handling cases to use that common function. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-14[POWERPC] Consolidate do_signalChristoph Hellwig
do_signal has exactly the same behaviour on 32bit and 64bit and 32bit compat on 64bit for handling 32bit signals. Consolidate all these into one common function in signal.c. The only odd left over is the try_to_free in the 32bit version that no other architecture has in mainline (only in i386 for some odd SuSE release). We should probably get rid of it in a separate patch. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-14[POWERPC] Consolidate restore_sigmaskChristoph Hellwig
restore_sigmask is exactly the same on 32 and 64bit, so move it to common code. Also move _BLOCKABLE to signal.h to avoid defining it multiple times. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-14[POWERPC] Consolidate sys_sigaltstackChristoph Hellwig
sys_sigaltstack is the same on 32bit and 64 and we can consolidate it to signal.c. The only difference is that the 32bit code uses ints for the unused register paramaters and 64bit unsigned long. I've changed it to unsigned long because it's the same width on 32bit. (I also wonder who came up with this awkward calling convention.. :)) Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-14[POWERPC] Make syscall restart code more commonBenjamin Herrenschmidt
This patch moves the code in signal_32.c and signal_64.c for handling syscall restart into a common signal.c file and converge around a single implementation that is based on the 32 bits one, using trap, ccr and r3 rather than the special "result" field for deciding what to do. The "result" field is now pretty much deprecated. We still set it for the sake of whatever might rely on it in userland but we no longer use it's content. This, along with a previous patch that enables ptracers to write to "trap" and "orig_r3" should allow gdb to properly handle syscall restarting. 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>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-12Merge branch 'merge'Paul Mackerras
2006-06-09[PATCH] powerpc: Implement support for setting little-endian mode via prctlPaul Mackerras
This adds the PowerPC part of the code to allow processes to change their endian mode via prctl. This also extends the alignment exception handler to be able to fix up alignment exceptions that occur in little-endian mode, both for "PowerPC" little-endian and true little-endian. We always enter signal handlers in big-endian mode -- the support for little-endian mode does not amount to the creation of a little-endian user/kernel ABI. If the signal handler returns, the endian mode is restored to what it was when the signal was delivered. We have two new kernel CPU feature bits, one for PPC little-endian and one for true little-endian. Most of the classic 32-bit processors support PPC little-endian, and this is reflected in the CPU feature table. There are two corresponding feature bits reported to userland in the AT_HWCAP aux vector entry. This is based on an earlier patch by Anton Blanchard. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-09[PATCH] powerpc vdso updatesBenjamin Herrenschmidt
This patch cleans up some locking & error handling in the ppc vdso and moves the vdso base pointer from the thread struct to the mm context where it more logically belongs. It brings the powerpc implementation closer to Ingo's new x86 one and also adds an arch_vma_name() function allowing to print [vsdo] in /proc/<pid>/maps if Ingo's x86 vdso patch is also applied. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-09powerpc: Fix machine check problem on 32-bit kernelsPaul Mackerras
This fixes a bug found by Dave Jones that means that it is possible for userspace to provoke a machine check on 32-bit kernels. This also fixes a couple of other places where I found similar problems by inspection. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-28[PATCH] powerpc: fix incorrect SA_ONSTACK behaviour for 64-bit processesLaurent MEYER
*) When setting a sighandler using sigaction() call, if the flag SA_ONSTACK is set and no alternate stack is provided via sigaltstack(), the kernel still try to install the alternate stack. This behavior is the opposite of the one which is documented in Single Unix Specifications V3. *) Also when setting an alternate stack using sigaltstack() with the flag SS_DISABLE, the kernel try to install the alternate stack on signal delivery. These two use cases makes the process crash at signal delivery. This fixes it. Signed-off-by: Laurent Meyer <meyerlau@fr.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-27[PATCH] powerpc: declare arch syscalls in <asm/syscalls.h>Arnd Bergmann
powerpc currently declares some of its own system calls in <asm/unistd.h>, but not all of them. That place also contains remainders of the now almost unused kernel syscall hack. - Add a new <asm/syscalls.h> with clean declarations - Include that file from every source that implements one of these - Get rid of old declarations in <asm/unistd.h> This patch is required as a base for implementing system calls from an SPU, but also makes sense as a general cleanup. Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-09Merge ../linux-2.6Paul Mackerras
2006-03-08powerpc: Fix various syscall/signal/swapcontext bugsPaul Mackerras
A careful reading of the recent changes to the system call entry/exit paths revealed several problems, plus some things that could be simplified and improved: * 32-bit wasn't testing the _TIF_NOERROR bit in the syscall fast exit path, so it was only doing anything with it once it saw some other bit being set. In other words, the noerror behaviour would apply to the next system call where we had to reschedule or deliver a signal, which is not necessarily the current system call. * 32-bit wasn't doing the call to ptrace_notify in the syscall exit path when the _TIF_SINGLESTEP bit was set. * _TIF_RESTOREALL was in both _TIF_USER_WORK_MASK and _TIF_PERSYSCALL_MASK, which is odd since _TIF_RESTOREALL is only set by system calls. I took it out of _TIF_USER_WORK_MASK. * On 64-bit, _TIF_RESTOREALL wasn't causing the non-volatile registers to be restored (unless perhaps a signal was delivered or the syscall was traced or single-stepped). Thus the non-volatile registers weren't restored on exit from a signal handler. We probably got away with it mostly because signal handlers written in C wouldn't alter the non-volatile registers. * On 32-bit I simplified the code and made it more like 64-bit by making the syscall exit path jump to ret_from_except to handle preemption and signal delivery. * 32-bit was calling do_signal unnecessarily when _TIF_RESTOREALL was set - but I think because of that 32-bit was actually restoring the non-volatile registers on exit from a signal handler. * I changed the order of enabling interrupts and saving the non-volatile registers before calling do_syscall_trace_leave; now we enable interrupts first. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-10[PATCH] powerpc: trivial: modify comments to refer to new location of filesJon Mason
This patch removes all self references and fixes references to files in the now defunct arch/ppc64 tree. I think this accomplises everything wanted, though there might be a few references I missed. Signed-off-by: Jon Mason <jdmason@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-08[PATCH] powerpc signal __user annotationsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-01-18[PATCH] TIF_RESTORE_SIGMASK support for arch/powerpcDavid Woodhouse
Implement the TIF_RESTORE_SIGMASK flag in the new arch/powerpc kernel, for both 32-bit and 64-bit system call paths. Signed-off-by: David Woodhouse <dwmw2@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-18[PATCH] Generic sys_rt_sigsuspend()David Woodhouse
The TIF_RESTORE_SIGMASK flag allows us to have a generic implementation of sys_rt_sigsuspend() instead of duplicating it for each architecture. This provides such an implementation and makes arch/powerpc use it. It also tidies up the ppc32 sys_sigsuspend() to use TIF_RESTORE_SIGMASK. Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12[PATCH] powerpc: Avoid potential FP corruption with preempt and UPPaul Mackerras
Heikki Lindholm pointed out that there was a potential race with the lazy CPU state (FP, VR, EVR) stuff if preempt is enabled. The race is that in the process of restoring FP state on sigreturn, the task gets preempted by a user task that wants to use the FPU. It will take an FP unavailable exception, which will write the current FPU state to the thread_struct, overwriting the values which sigreturn has stored. Note that this can only happen on UP since we don't implement lazy CPU state on SMP. The fix is to flush the lazy CPU state before updating the thread_struct. To do this we re-use the flush_lazy_cpu_state() function from process.c. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-09[PATCH] syscall entry/exit revampDavid Woodhouse
This cleanup patch speeds up the null syscall path on ppc64 by about 3%, and brings the ppc32 and ppc64 code slightly closer together. The ppc64 code was checking current_thread_info()->flags twice in the syscall exit path; once for TIF_SYSCALL_T_OR_A before disabling interrupts, and then again for TIF_SIGPENDING|TIF_NEED_RESCHED etc after disabling interrupts. Now we do the same as ppc32 -- check the flags only once in the fast path, and re-enable interrupts if necessary in the ptrace case. The patch abolishes the 'syscall_noerror' member of struct thread_info and replaces it with a TIF_NOERROR bit in the flags, which is handled in the slow path. This shortens the syscall entry code, which no longer needs to clear syscall_noerror. The patch adds a TIF_SAVE_NVGPRS flag which causes the syscall exit slow path to save the non-volatile GPRs into a signal frame. This removes the need for the assembly wrappers around sys_sigsuspend(), sys_rt_sigsuspend(), et al which existed solely to save those registers in advance. It also means I don't have to add new wrappers for ppoll() and pselect(), which is what I was supposed to be doing when I got distracted into this... Finally, it unifies the ppc64 and ppc32 methods of handling syscall exit directly into a signal handler (as required by sigsuspend et al) by introducing a TIF_RESTOREALL flag which causes _all_ the registers to be reloaded from the pt_regs by taking the ret_from_exception path, instead of the normal syscall exit path which stomps on the callee-saved GPRs. It appears to pass an LTP test run on ppc64, and passes basic testing on ppc32 too. Brief tests of ptrace functionality with strace and gdb also appear OK. I wouldn't send it to Linus for 2.6.15 just yet though :) Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-15powerpc: Fix clearing of the FPSCR when invoking a signal handlerPaul Mackerras
As pointed out by Gary Byers, we were clearing the image of the FPSCR (floating point status and control register) in the thread_struct before copying it to the user stack when invoking a signal. Thus the task would see its FPSCR getting cleared when it took a signal. While fixing it I noticed that our swapcontext system call was also clearing FPSCR. It shouldn't, so I fixed that too. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-07[PATCH] powerpc: Kill ppcdebugDavid Gibson
The ancient ppcdebug/PPCDBG mechanism is now only used in two places. First, in the hash setup code, one of the bits allows the size of the hash table to be reduced by a factor of 8 - which would be better accomplished with a command line option for that purpose. The other was a bunch of bus walking related messages in the iSeries code, which would seem to be insufficient reason to keep the mechanism. This patch removes the last traces of this mechanism. Built and booted on iSeries and pSeries POWER5 LPAR (ARCH=powerpc). Signed-off-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-03powerpc: move ppc64/kernel/signal.c to arch/powerpcStephen Rothwell
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>