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2013-06-01powerpc/tm: Fix userspace stack corruption on signal delivery for active ↵Michael Neuling
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>
2013-05-14powerpc: Set show_unhandled_signals to 1 by defaultBenjamin Herrenschmidt
Just like other architectures Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14powerpc: Exit user context on notify resumeLi Zhong
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>
2013-02-23Merge branch 'for-linus' of ↵Linus Torvalds
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() ...
2013-02-03powerpc: switch to generic sigaltstackAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-01-16powerpc: Rename set_break to avoid naming conflictMichael Neuling
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>
2013-01-10powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registersMichael Neuling
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>
2012-11-03uprobes/powerpc: Don't clear TIF_UPROBE in do_notify_resume()Oleg Nesterov
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>
2012-09-10powerpc: Rework set_dabr so it can take a DABRX value as wellMichael Neuling
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>
2012-09-05powerpc: Uprobes port to powerpcAnanth N Mavinakayanahalli
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>
2012-06-01new helper: signal_delivered()Al Viro
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>
2012-06-01powerpc: get rid of restore_sigmask()Al Viro
... it's just a call of set_current_blocked() now Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from setAl Viro
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>
2012-06-01pull clearing RESTORE_SIGMASK into block_sigmask()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01new helper: sigmask_to_save()Al Viro
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>
2012-06-01new helper: restore_saved_sigmask()Al Viro
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>
2012-05-23move key_repace_session_keyring() into tracehook_notify_resume()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-28Disintegrate asm/system.h for PowerPCDavid Howells
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
2012-03-07powerpc: Use set_current_blocked() and block_sigmask()Matt Fleming
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>
2012-02-22powerpc: Fix various issues with return to userspaceBenjamin Herrenschmidt
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> ---
2010-09-22powerpc: fix double syscall restartsAl Viro
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>
2010-06-22powerpc, hw_breakpoint: Enable hw-breakpoints while handling intervening signalsK.Prasad
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>
2010-02-17powerpc/booke: Add support for advanced debug registersDave Kleikamp
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>
2010-02-17powerpc/booke: Introduce new CONFIG options for advanced debug registersDave Kleikamp
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>
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>
2008-07-28powerpc: Add TIF_NOTIFY_RESUME support for tracehookRoland McGrath
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>
2008-07-28powerpc: Call tracehook_signal_handler() when setting up signal framesRoland McGrath
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>
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>
2008-05-14[POWERPC] Define and use TLF_RESTORE_SIGMASKRoland McGrath
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>
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>
2007-06-14[POWERPC] Less ifdef's in signal.c/signal.hBenjamin Herrenschmidt
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>
2007-06-14[POWERPC] Remove #ifdef around set_dabr in signal codeBenjamin Herrenschmidt
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>
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] Remove obsolete freezer bitsBenjamin Herrenschmidt
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>
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>