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* powerpc/signal: Properly handle return value from uprobe_deny_signal()Naveen N. Rao2017-11-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | When a uprobe is installed on an instruction that we currently do not emulate, we copy the instruction into a xol buffer and single step that instruction. If that instruction generates a fault, we abort the single stepping before invoking the signal handler. Once the signal handler is done, the uprobe trap is hit again since the instruction is retried and the process repeats. We use uprobe_deny_signal() to detect if the xol instruction triggered a signal. If so, we clear TIF_SIGPENDING and set TIF_UPROBE so that the signal is not handled until after the single stepping is aborted. In this case, uprobe_deny_signal() returns true and get_signal() ends up returning 0. However, in do_signal(), we are not looking at the return value, but depending on ksig.sig for further action, all with an uninitialized ksig that is not touched in this scenario. Fix the same by initializing ksig.sig to 0. Fixes: 129b69df9c90 ("powerpc: Use get_signal() signal_setup_done()") Cc: stable@vger.kernel.org # v3.17+ Reported-by: Anton Blanchard <anton@samba.org> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* livepatch/powerpc: add TIF_PATCH_PENDING thread flagJosh Poimboeuf2017-03-081-0/+4
| | | | | | | | | | | | | | | | | | | Add the TIF_PATCH_PENDING thread flag to enable the new livepatch per-task consistency model for powerpc. The bit getting set indicates the thread has a pending patch which needs to be applied when the thread exits the kernel. The bit is included in the _TIF_USER_WORK_MASK macro so that do_notify_resume() and klp_update_patch_state() get called when the bit is set. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Reviewed-by: Balbir Singh <bsingharora@gmail.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds2016-12-241-1/+1
| | | | | | | | | | | | | This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* powerpc: signals: Stop using current in signal codeCyril Bur2016-10-041-18/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | Much of the signal code takes a pt_regs on which it operates. Over time the signal code has needed to know more about the thread than what pt_regs can supply, this information is obtained as needed by using 'current'. This approach is not strictly incorrect however it does mean that there is now a hard requirement that the pt_regs being passed around does belong to current, this is never checked. A safer approach is for the majority of the signal functions to take a task_struct from which they can obtain pt_regs and any other information they need. The caveat that the task_struct they are passed must be current doesn't go away but can more easily be checked for. Functions called from outside powerpc signal code are passed a pt_regs and they can confirm that the pt_regs is that of current and pass current to other functions, furthurmore, powerpc signal functions can check that the task_struct they are passed is the same as current avoiding possible corruption of current (or the task they are passed) if this assertion ever fails. CC: paulus@samba.org Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc: Fix misspellings in comments.Adam Buchbinder2016-03-011-2/+2
| | | | | Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc: Use sigsp()Richard Weinberger2014-08-061-8/+2
| | | | | | Use sigsp() instead of the open coded variant. Signed-off-by: Richard Weinberger <richard@nod.at>
* powerpc: Use get_signal() signal_setup_done()Richard Weinberger2014-08-061-20/+11
| | | | | | | | | Use the more generic functions get_signal() signal_setup_done() for signal delivery. This inverts also the return codes of setup_*frame() to follow the kernel convention. Signed-off-by: Richard Weinberger <richard@nod.at>
* powerpc: Fix smp_processor_id() in preemptible splat in set_breakpointPaul Gortmaker2014-05-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, on 8641D, which doesn't set CONFIG_HAVE_HW_BREAKPOINT we get the following splat: BUG: using smp_processor_id() in preemptible [00000000] code: login/1382 caller is set_breakpoint+0x1c/0xa0 CPU: 0 PID: 1382 Comm: login Not tainted 3.15.0-rc3-00041-g2aafe1a4d451 #1 Call Trace: [decd5d80] [c0008dc4] show_stack+0x50/0x158 (unreliable) [decd5dc0] [c03c6fa0] dump_stack+0x7c/0xdc [decd5de0] [c01f8818] check_preemption_disabled+0xf4/0x104 [decd5e00] [c00086b8] set_breakpoint+0x1c/0xa0 [decd5e10] [c00d4530] flush_old_exec+0x2bc/0x588 [decd5e40] [c011c468] load_elf_binary+0x2ac/0x1164 [decd5ec0] [c00d35f8] search_binary_handler+0xc4/0x1f8 [decd5ef0] [c00d4ee8] do_execve+0x3d8/0x4b8 [decd5f40] [c001185c] ret_from_syscall+0x0/0x38 --- Exception: c01 at 0xfeee554 LR = 0xfeee7d4 The call path in this case is: flush_thread --> set_debug_reg_defaults --> set_breakpoint --> __get_cpu_var Since preemption is enabled in the cleanup of flush thread, and there is no need to disable it, introduce the distinction between set_breakpoint and __set_breakpoint, leaving only the flush_thread instance as the current user of set_breakpoint. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Don't corrupt transactional state when using FP/VMX in kernelPaul Mackerras2014-01-151-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, when we have a process using the transactional memory facilities on POWER8 (that is, the processor is in transactional or suspended state), and the process enters the kernel and the kernel then uses the floating-point or vector (VMX/Altivec) facility, we end up corrupting the user-visible FP/VMX/VSX state. This happens, for example, if a page fault causes a copy-on-write operation, because the copy_page function will use VMX to do the copy on POWER8. The test program below demonstrates the bug. The bug happens because when FP/VMX state for a transactional process is stored in the thread_struct, we store the checkpointed state in .fp_state/.vr_state and the transactional (current) state in .transact_fp/.transact_vr. However, when the kernel wants to use FP/VMX, it calls enable_kernel_fp() or enable_kernel_altivec(), which saves the current state in .fp_state/.vr_state. Furthermore, when we return to the user process we return with FP/VMX/VSX disabled. The next time the process uses FP/VMX/VSX, we don't know which set of state (the current register values, .fp_state/.vr_state, or .transact_fp/.transact_vr) we should be using, since we have no way to tell if we are still in the same transaction, and if not, whether the previous transaction succeeded or failed. Thus it is necessary to strictly adhere to the rule that if FP has been enabled at any point in a transaction, we must keep FP enabled for the user process with the current transactional state in the FP registers, until we detect that it is no longer in a transaction. Similarly for VMX; once enabled it must stay enabled until the process is no longer transactional. In order to keep this rule, we add a new thread_info flag which we test when returning from the kernel to userspace, called TIF_RESTORE_TM. This flag indicates that there is FP/VMX/VSX state to be restored before entering userspace, and when it is set the .tm_orig_msr field in the thread_struct indicates what state needs to be restored. The restoration is done by restore_tm_state(). The TIF_RESTORE_TM bit is set by new giveup_fpu/altivec_maybe_transactional helpers, which are called from enable_kernel_fp/altivec, giveup_vsx, and flush_fp/altivec_to_thread instead of giveup_fpu/altivec. The other thing to be done is to get the transactional FP/VMX/VSX state from .fp_state/.vr_state when doing reclaim, if that state has been saved there by giveup_fpu/altivec_maybe_transactional. Having done this, we set the FP/VMX bit in the thread's MSR after reclaim to indicate that that part of the state is now valid (having been reclaimed from the processor's checkpointed state). Finally, in the signal handling code, we move the clearing of the transactional state bits in the thread's MSR a bit earlier, before calling flush_fp_to_thread(), so that we don't unnecessarily set the TIF_RESTORE_TM bit. This is the test program: /* Michael Neuling 4/12/2013 * * See if the altivec state is leaked out of an aborted transaction due to * kernel vmx copy loops. * * gcc -m64 htm_vmxcopy.c -o htm_vmxcopy * */ /* We don't use all of these, but for reference: */ int main(int argc, char *argv[]) { long double vecin = 1.3; long double vecout; unsigned long pgsize = getpagesize(); int i; int fd; int size = pgsize*16; char tmpfile[] = "/tmp/page_faultXXXXXX"; char buf[pgsize]; char *a; uint64_t aborted = 0; fd = mkstemp(tmpfile); assert(fd >= 0); memset(buf, 0, pgsize); for (i = 0; i < size; i += pgsize) assert(write(fd, buf, pgsize) == pgsize); unlink(tmpfile); a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); assert(a != MAP_FAILED); asm __volatile__( "lxvd2x 40,0,%[vecinptr] ; " // set 40 to initial value TBEGIN "beq 3f ;" TSUSPEND "xxlxor 40,40,40 ; " // set 40 to 0 "std 5, 0(%[map]) ;" // cause kernel vmx copy page TABORT TRESUME TEND "li %[res], 0 ;" "b 5f ;" "3: ;" // Abort handler "li %[res], 1 ;" "5: ;" "stxvd2x 40,0,%[vecoutptr] ; " : [res]"=r"(aborted) : [vecinptr]"r"(&vecin), [vecoutptr]"r"(&vecout), [map]"r"(a) : "memory", "r0", "r3", "r4", "r5", "r6", "r7"); if (aborted && (vecin != vecout)){ printf("FAILED: vector state leaked on abort %f != %f\n", (double)vecin, (double)vecout); exit(1); } munmap(a, size); close(fd); printf("PASSED!\n"); return 0; } Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/tm: Fix userspace stack corruption on signal delivery for active ↵Michael Neuling2013-06-011-2/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | transactions When in an active transaction that takes a signal, we need to be careful with the stack. It's possible that the stack has moved back up after the tbegin. The obvious case here is when the tbegin is called inside a function that returns before a tend. In this case, the stack is part of the checkpointed transactional memory state. If we write over this non transactionally or in suspend, we are in trouble because if we get a tm abort, the program counter and stack pointer will be back at the tbegin but our in memory stack won't be valid anymore. To avoid this, when taking a signal in an active transaction, we need to use the stack pointer from the checkpointed state, rather than the speculated state. This ensures that the signal context (written tm suspended) will be written below the stack required for the rollback. The transaction is aborted becuase of the treclaim, so any memory written between the tbegin and the signal will be rolled back anyway. For signals taken in non-TM or suspended mode, we use the normal/non-checkpointed stack pointer. Tested with 64 and 32 bit signals Signed-off-by: Michael Neuling <mikey@neuling.org> Cc: <stable@vger.kernel.org> # v3.9 Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Set show_unhandled_signals to 1 by defaultBenjamin Herrenschmidt2013-05-141-1/+1
| | | | | | Just like other architectures Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Exit user context on notify resumeLi Zhong2013-05-141-0/+5
| | | | | | | | | | This patch allows RCU usage in do_notify_resume, e.g. signal handling. It corresponds to [PATCH] x86: Exit RCU extended QS on notify resume commit edf55fda35c7dc7f2d9241c3abaddaf759b457c6 Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-02-231-7/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull signal handling cleanups from Al Viro: "This is the first pile; another one will come a bit later and will contain SYSCALL_DEFINE-related patches. - a bunch of signal-related syscalls (both native and compat) unified. - a bunch of compat syscalls switched to COMPAT_SYSCALL_DEFINE (fixing several potential problems with missing argument validation, while we are at it) - a lot of now-pointless wrappers killed - a couple of architectures (cris and hexagon) forgot to save altstack settings into sigframe, even though they used the (uninitialized) values in sigreturn; fixed. - microblaze fixes for delivery of multiple signals arriving at once - saner set of helpers for signal delivery introduced, several architectures switched to using those." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (143 commits) x86: convert to ksignal sparc: convert to ksignal arm: switch to struct ksignal * passing alpha: pass k_sigaction and siginfo_t using ksignal pointer burying unused conditionals make do_sigaltstack() static arm64: switch to generic old sigaction() (compat-only) arm64: switch to generic compat rt_sigaction() arm64: switch compat to generic old sigsuspend arm64: switch to generic compat rt_sigqueueinfo() arm64: switch to generic compat rt_sigpending() arm64: switch to generic compat rt_sigprocmask() arm64: switch to generic sigaltstack sparc: switch to generic old sigsuspend sparc: COMPAT_SYSCALL_DEFINE does all sign-extension as well as SYSCALL_DEFINE sparc: kill sign-extending wrappers for native syscalls kill sparc32_open() sparc: switch to use of generic old sigaction sparc: switch sys_compat_rt_sigaction() to COMPAT_SYSCALL_DEFINE mips: switch to generic sys_fork() and sys_clone() ...
| * powerpc: switch to generic sigaltstackAl Viro2013-02-031-7/+0
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | powerpc: Rename set_break to avoid naming conflictMichael Neuling2013-01-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With allmodconfig we are getting: drivers/tty/synclink_gt.c:160:12: error: conflicting types for 'set_break' arch/powerpc/include/asm/debug.h:49:5: note: previous declaration of 'set_break' was here drivers/tty/synclinkmp.c:526:12: error: conflicting types for 'set_break' arch/powerpc/include/asm/debug.h:49:5: note: previous declaration of 'set_break' was here This renames set_break to set_breakpoint to avoid this naming conflict Signed-off-by: Michael Neuling <mikey@neuling.org> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registersMichael Neuling2013-01-101-2/+3
|/ | | | | | | | | | | | | This is a rewrite so that we don't assume we are using the DABR throughout the code. We now use the arch_hw_breakpoint to store the breakpoint in a generic manner in the thread_struct, rather than storing the raw DABR value. The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from userspace. We keep this functionality, so that future changes (like the POWER8 DAWR), will still fake the DABR to userspace. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* uprobes/powerpc: Don't clear TIF_UPROBE in do_notify_resume()Oleg Nesterov2012-11-031-3/+1
| | | | | | | | Cleanup. No need to clear TIF_UPROBE, uprobe_notify_resume() does this. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
* powerpc: Rework set_dabr so it can take a DABRX value as wellMichael Neuling2012-09-101-1/+1
| | | | | | | | | | | | | Rework set_dabr to take a DABRX value as well. Both the pseries and PS3 hypervisors do some checks on the DABRX values that are passed in the hcall. This patch stops bogus values from being passed to hypervisor. Also, in the case where we are clearing the breakpoint, where DABR and DABRX are zero, we modify the DABRX value to make it valid so that the hcall won't fail. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Uprobes port to powerpcAnanth N Mavinakayanahalli2012-09-051-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the port of uprobes to powerpc. Usage is similar to x86. [root@xxxx ~]# ./bin/perf probe -x /lib64/libc.so.6 malloc Added new event: probe_libc:malloc (on 0xb4860) You can now use it in all perf tools, such as: perf record -e probe_libc:malloc -aR sleep 1 [root@xxxx ~]# ./bin/perf record -e probe_libc:malloc -aR sleep 20 [ perf record: Woken up 22 times to write data ] [ perf record: Captured and wrote 5.843 MB perf.data (~255302 samples) ] [root@xxxx ~]# ./bin/perf report --stdio ... 69.05% tar libc-2.12.so [.] malloc 28.57% rm libc-2.12.so [.] malloc 1.32% avahi-daemon libc-2.12.so [.] malloc 0.58% bash libc-2.12.so [.] malloc 0.28% sshd libc-2.12.so [.] malloc 0.08% irqbalance libc-2.12.so [.] malloc 0.05% bzip2 libc-2.12.so [.] malloc 0.04% sleep libc-2.12.so [.] malloc 0.03% multipathd libc-2.12.so [.] malloc 0.01% sendmail libc-2.12.so [.] malloc 0.01% automount libc-2.12.so [.] malloc The trap_nr addition patch is a prereq. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* new helper: signal_delivered()Al Viro2012-06-011-5/+1
| | | | | | | | | | | | | | Does block_sigmask() + tracehook_signal_handler(); called when sigframe has been successfully built. All architectures converted to it; block_sigmask() itself is gone now (merged into this one). I'm still not too happy with the signature, but that's a separate story (IMO we need a structure that would contain signal number + siginfo + k_sigaction, so that get_signal_to_deliver() would fill one, signal_delivered(), handle_signal() and probably setup...frame() - take one). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* powerpc: get rid of restore_sigmask()Al Viro2012-06-011-9/+0
| | | | | | ... it's just a call of set_current_blocked() now Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from setAl Viro2012-06-011-1/+0
| | | | | | | | Only 3 out of 63 do not. Renamed the current variant to __set_current_blocked(), added set_current_blocked() that will exclude unblockable signals, switched open-coded instances to it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* pull clearing RESTORE_SIGMASK into block_sigmask()Al Viro2012-06-011-7/+0
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* new helper: sigmask_to_save()Al Viro2012-06-011-6/+1
| | | | | | | replace boilerplate "should we use ->saved_sigmask or ->blocked?" with calls of obvious inlined helper... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* new helper: restore_saved_sigmask()Al Viro2012-06-011-5/+1
| | | | | | | | | first fruits of ..._restore_sigmask() helpers: now we can take boilerplate "signal didn't have a handler, clear RESTORE_SIGMASK and restore the blocked mask from ->saved_mask" into a common helper. Open-coded instances switched... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* move key_repace_session_keyring() into tracehook_notify_resume()Al Viro2012-05-231-2/+0
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Disintegrate asm/system.h for PowerPCDavid Howells2012-03-281-0/+1
| | | | | | | | Disintegrate asm/system.h for PowerPC. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> cc: linuxppc-dev@lists.ozlabs.org
* powerpc: Use set_current_blocked() and block_sigmask()Matt Fleming2012-03-071-11/+2
| | | | | | | | | | | | | | | | | | | | | | As described in e6fa16ab ("signal: sigprocmask() should do retarget_shared_pending()") the modification of current->blocked is incorrect as we need to check whether the signal we're about to block is pending in the shared queue. Also, use the new helper function introduced in commit 5e6292c0f28f ("signal: add block_sigmask() for adding sigmask to current->blocked") which centralises the code for updating current->blocked after successfully delivering a signal and reduces the amount of duplicate code across architectures. In the past some architectures got this code wrong, so using this helper function should stop that from happening again. Cc: Oleg Nesterov <oleg@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fix various issues with return to userspaceBenjamin Herrenschmidt2012-02-221-4/+8
| | | | | | | | | | | | | | | | | | | | We have a few problems when returning to userspace. This is a quick set of fixes for 3.3, I'll look into a more comprehensive rework for 3.4. This fixes: - We kept interrupts soft-disabled when schedule'ing or calling do_signal when returning to userspace as a result of a hardware interrupt. - Rename do_signal to do_notify_resume like all other archs (and do_signal_pending back to do_signal, which it was before Roland changed it). - Add the missing call to key_replace_session_keyring() to do_notify_resume(). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> ---
* powerpc: fix double syscall restartsAl Viro2010-09-221-0/+2
| | | | | | | | | | | | | | Make sigreturn zero regs->trap, make do_signal() do the same on all paths. As it is, signal interrupting e.g. read() from fd 512 (== ERESTARTSYS) with another signal getting unblocked when the first handler finishes will lead to restart one insn earlier than it ought to. Same for multiple signals with in-kernel handlers interrupting that sucker at the same time. Same for multiple signals of any kind interrupting that sucker on 64bit... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* powerpc, hw_breakpoint: Enable hw-breakpoints while handling intervening signalsK.Prasad2010-06-221-0/+3
| | | | | | | | | | | | | | | | | | | | A signal delivered between a hw_breakpoint_handler() and the single_step_dabr_instruction() will not have the breakpoint active while the signal handler is running -- the signal delivery will set up a new MSR value which will not have MSR_SE set, so we won't get the signal step interrupt until and unless the signal handler returns (which it may never do). To fix this, we restore the breakpoint when delivering a signal -- we clear the MSR_SE bit and set the DABR again. If the signal handler returns, the DABR interrupt will occur again when the instruction that we were originally trying to single-step gets re-executed. [Paul Mackerras <paulus@samba.org> pointed out the need to do this.] Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
* powerpc/booke: Add support for advanced debug registersDave Kleikamp2010-02-171-4/+2
| | | | | | | | | | | | | | | | | | | | | | | powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/booke: Introduce new CONFIG options for advanced debug registersDave Kleikamp2010-02-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | powerpc/booke: Introduce new CONFIG options for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Introduce new config options to simplify the ifdefs pertaining to the advanced debug registers for booke and 40x processors: CONFIG_PPC_ADV_DEBUG_REGS - boolean: true for dac-based processors CONFIG_PPC_ADV_DEBUG_IACS - number of IAC registers CONFIG_PPC_ADV_DEBUG_DACS - number of DAC registers CONFIG_PPC_ADV_DEBUG_DVCS - number of DVC registers CONFIG_PPC_ADV_DEBUG_DAC_RANGE - DAC ranges supported Beginning conservatively, since I only have the facilities to test 440 hardware. I believe all 40x and booke platforms support at least 2 IAC and 2 DAC registers. For 440, 4 IAC and 2 DVC registers are enabled, as well as the DAC ranges. Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Acked-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Sanitize stack pointer in signal handling codeJosh Boyer2009-03-271-2/+2
| | | | | | | | | | | | | | | | | | | 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>
* powerpc: Add TIF_NOTIFY_RESUME support for tracehookRoland McGrath2008-07-281-1/+12
| | | | | | | | | | | This adds TIF_NOTIFY_RESUME support for powerpc. When set, we call tracehook_notify_resume() on the way to user mode. This overloads do_signal() to do the work, but changes its arguments to it has the TIF_* bits handy in a register and drops the useless first argument that was always zero. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Call tracehook_signal_handler() when setting up signal framesRoland McGrath2008-07-281-1/+7
| | | | | | | | | | | | | This makes the powerpc signal handling code call tracehook_signal_handler() after a handler is set up. This means that using PTRACE_SINGLESTEP to enter a signal handler will report to ptrace on the first instruction of the handler, instead of the second. This is consistent with what x86 and other machines do, and what users and debuggers want. BenH: Fixed up the test for the trap value. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/booke: Clean up the hardware watchpoint supportKumar Gala2008-07-281-1/+1
| | | | | | | | | | * 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>
* powerpc: BookE hardware watchpoint supportLuis Machado2008-07-251-1/+5
| | | | | | | | | | | | 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>
* [POWERPC] Define and use TLF_RESTORE_SIGMASKRoland McGrath2008-05-141-6/+6
| | | | | | | | | | Replace TIF_RESTORE_SIGMASK with TLF_RESTORE_SIGMASK and define our own set_restore_sigmask() function. This saves the costly SMP-safe set_bit operation, which we do not need for the sigmask flag since TIF_SIGPENDING always has to be set too. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] Implement logging of unhandled signalsOlof Johansson2007-10-121-0/+6
| | | | | | | | | | 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>
* [POWERPC] Less ifdef's in signal.c/signal.hBenjamin Herrenschmidt2007-06-141-15/+0
| | | | | | | | | This patch moves things around a little bit in the new common signal.c and signal.h files to remove the last #ifdef in the middle of the common do_signal(). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] Remove #ifdef around set_dabr in signal codeBenjamin Herrenschmidt2007-06-141-2/+0
| | | | | | | | | | set_dabr() and thread.dabr exist on 32 bits as well nowadays (they actually may do something even, depending on what CPU you have). So this removes the ifdef. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] Merge creation of signal frameBenjamin Herrenschmidt2007-06-141-10/+29
| | | | | | | | | | | | | | | 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>
* [POWERPC] Remove obsolete freezer bitsBenjamin Herrenschmidt2007-06-141-12/+0
| | | | | | | | The powerpc signal code still had some obsolete freezer bits that have long been removed from x86 (it's now done in generic code). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] Consolidate do_signalChristoph Hellwig2007-06-141-2/+105
| | | | | | | | | | | | | 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>
* [POWERPC] Consolidate restore_sigmaskChristoph Hellwig2007-06-141-0/+15
| | | | | | | | | | 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>
* [POWERPC] Consolidate sys_sigaltstackChristoph Hellwig2007-06-141-0/+7
| | | | | | | | | | | | | 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>
* [POWERPC] Make syscall restart code more commonBenjamin Herrenschmidt2007-06-141-0/+65
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>