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* signal: Don't use structure initializers for struct siginfoEric W. Biederman2018-01-221-1/+3
| | | | | | | | | | | The siginfo structure has all manners of holes with the result that a structure initializer is not guaranteed to initialize all of the bits. As we have to copy the structure to userspace don't even try to use a structure initializer. Instead use clear_siginfo followed by initializing selected fields. This gives a guarantee that uninitialized kernel memory is not copied to userspace. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* signal: Remove kernel interal si_code magicEric W. Biederman2017-07-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | struct siginfo is a union and the kernel since 2.4 has been hiding a union tag in the high 16bits of si_code using the values: __SI_KILL __SI_TIMER __SI_POLL __SI_FAULT __SI_CHLD __SI_RT __SI_MESGQ __SI_SYS While this looks plausible on the surface, in practice this situation has not worked well. - Injected positive signals are not copied to user space properly unless they have these magic high bits set. - Injected positive signals are not reported properly by signalfd unless they have these magic high bits set. - These kernel internal values leaked to userspace via ptrace_peek_siginfo - It was possible to inject these kernel internal values and cause the the kernel to misbehave. - Kernel developers got confused and expected these kernel internal values in userspace in kernel self tests. - Kernel developers got confused and set si_code to __SI_FAULT which is SI_USER in userspace which causes userspace to think an ordinary user sent the signal and that it was not kernel generated. - The values make it impossible to reorganize the code to transform siginfo_copy_to_user into a plain copy_to_user. As si_code must be massaged before being passed to userspace. So remove these kernel internal si codes and make the kernel code simpler and more maintainable. To replace these kernel internal magic si_codes introduce the helper function siginfo_layout, that takes a signal number and an si_code and computes which union member of siginfo is being used. Have siginfo_layout return an enumeration so that gcc will have enough information to warn if a switch statement does not handle all of union members. A couple of architectures have a messed up ABI that defines signal specific duplications of SI_USER which causes more special cases in siginfo_layout than I would like. The good news is only problem architectures pay the cost. Update all of the code that used the previous magic __SI_ values to use the new SIL_ values and to call siginfo_layout to get those values. Escept where not all of the cases are handled remove the defaults in the switch statements so that if a new case is missed in the future the lack will show up at compile time. Modify the code that copies siginfo si_code to userspace to just copy the value and not cast si_code to a short first. The high bits are no longer used to hold a magic union member. Fixup the siginfo header files to stop including the __SI_ values in their constants and for the headers that were missing it to properly update the number of si_codes for each signal type. The fixes to copy_siginfo_from_user32 implementations has the interesting property that several of them perviously should never have worked as the __SI_ values they depended up where kernel internal. With that dependency gone those implementations should work much better. The idea of not passing the __SI_ values out to userspace and then not reinserting them has been tested with criu and criu worked without changes. Ref: 2.4.0-test1 Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | <linux/sched/debug.h> We are going to split <linux/sched/debug.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/debug.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* arch/tile: adopt the new nmi_backtrace frameworkChris Metcalf2016-10-071-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously tile was rolling its own method of capturing backtrace data in the NMI handlers, but it was relying on running printk() from the NMI handler, which is not always safe. So adopt the nmi_backtrace model (with the new cpumask extension) instead. So we can call the nmi_backtrace code directly from the nmi handler, move the nmi_enter()/exit() into the top-level tile NMI handler. The semantics of the routine change slightly since it is now synchronous with the remote cores completing the backtraces. Previously it was asynchronous, but with protection to avoid starting a new remote backtrace if the old one was still in progress. Link: http://lkml.kernel.org/r/1472487169-14923-4-git-send-email-cmetcalf@mellanox.com Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> [arm] Cc: Petr Mladek <pmladek@suse.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* arch/tile: move user_exit() to early kernel entry sequenceChris Metcalf2016-01-181-9/+4
| | | | | | | | | | | | This ensures that we always notify context tracking that we have exited from user space no matter how we enter the kernel. It is similar to how arm64 handles context tracking, for example. This allows the removal of all the exception_enter() calls that were added in commit 49e4e15619cd ("tile: support CONTEXT_TRACKING and thus NOHZ_FULL"). Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
* tile: improve stack backtraceChris Metcalf2015-05-111-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit fixes a number of issues with the tile backtrace code. - Don't try to identify userspace shared object or executable paths if we are doing a backtrace from an interrupt; it's not legal, and also unlikely to be interesting. Likewise, don't try to do it for other address spaces, since d_path() assumes it is being called in "current" context. - Move "in_backtrace" from thread_struct to thread_info. This way we can access it even if our stack thread_info has been clobbered, which makes backtracing more robust. - Avoid using "current" directly when testing for is_sigreturn(). Since "current" may be corrupt, we're better off using kbt->task explicitly to look up the vdso_base for the current task. Conveniently, this simplifies the internal APIs (we only need one is_sigreturn() function now). - Avoid bogus "Odd fault" warning when pc/sp/ex1 are all zero, as is true for kernel threads above the last frame. - Hook into Tejun Heo's dump_stack() framework in lib/dump_stack.c. - Write last entry in save_stack_trace() as ULONG_MAX, not zero, since ftrace (at least) relies on finding that marker. - Implement save_stack_trace_regs() and save_strack_trace_user(), and set CONFIG_USER_STACKTRACE_SUPPORT. Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
* tile: support delivering NMIs for multicore backtraceChris Metcalf2015-05-111-0/+12
| | | | | | | | | | A new hypervisor service was added some time ago (MDE 4.2.1 or later, or MDE 4.3 or later) that allows cores to request NMIs to be delivered to other cores. Use this facility to deliver a request that causes a backtrace to be generated on each core, and hook it into the magic SysRq functionality. Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
* tile: support CONTEXT_TRACKING and thus NOHZ_FULLChris Metcalf2015-04-171-7/+9
| | | | | | | | | | | | | | | | Add the TIF_NOHZ flag appropriately. Add call to user_exit() on entry to do_work_pending() and on entry to syscalls via do_syscall_trace_enter(), and also the top of do_syscall_trace_exit() just because it's done in x86. Add call to user_enter() at the bottom of do_work_pending() once we have no more work to do before returning to userspace. Wrap all the trap code in exception_enter() / exception_exit(). Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
* tile: Use the more common pr_warn instead of pr_warningJoe Perches2014-11-111-5/+5
| | | | | | | | | | | | | | And other message logging neatening. Other miscellanea: o coalesce formats o realign arguments o standardize a couple of macros o use __func__ instead of embedding the function name Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* tile: use ARRAY_SIZEHimangi Saraogi2014-10-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | ARRAY_SIZE is more concise to use when the size of an array is divided by the size of its type or the size of its first element. The semantic patch that makes this change is as follows: // <smpl> @i@ @@ @@ type T; T[] E; @@ - (sizeof(E)/sizeof(T)) + ARRAY_SIZE(E) // </smpl> Signed-off-by: Himangi Saraogi <himangi774@gmail.com> Acked-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* replace strict_strto* call with kstrto*Daniel Walter2014-05-281-3/+2
| | | | | | | | remove obsolete calls to strict_strto* and replace them with kstrto* calls accordingly. Signed-off-by: Daniel Walter <dwalter@google.com> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* tile: use standard tile_bundle_bits type in traps.cChris Metcalf2013-09-031-9/+3
| | | | | | We were rolling our own bundle_bits, which is unnecessary. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* tilegx: support KGDBChris Metcalf2013-09-031-0/+5
| | | | | | | | | | Enter kernel debugger at boot with: --hvd UART_1=1 --hvx kgdbwait --hvx kgdboc=ttyS1,115200 or at runtime with: echo ttyS1,115200 > /sys/module/kgdboc/parameters/kgdboc echo g > /proc/sysrq-trigger Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* tile: parameterize VA and PA space more cleanlyChris Metcalf2013-09-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | The existing code relied on the hardware definition (<arch/chip.h>) to specify how much VA and PA space was available. It's convenient to allow customizing this for some configurations, so provide symbols MAX_PA_WIDTH and MAX_VA_WIDTH in <asm/page.h> that can be modified if desired. Additionally, move away from the MEM_XX_INTRPT nomenclature to define the start of various regions within the VA space. In fact the cleaner symbol is, for example, MEM_SV_START, to indicate the start of the area used for supervisor code; the actual address of the interrupt vectors is not as important, and can be changed if desired. As part of this change, convert from "intrpt1" nomenclature (which built in the old privilege-level 1 model) to a simple "intrpt". Also strip out some tilepro-specific code supporting modifying the PL the kernel could run at, since we don't actually support using different PLs in tilepro, only tilegx. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* tile: support kprobes on tilegxTony Lu2013-08-301-1/+44
| | | | | | | | This change includes support for Kprobes, Jprobes and Return Probes. Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Tony Lu <zlu@tilera.com> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* tile: improve illegal translation interrupt handlingChris Metcalf2013-08-131-10/+15
| | | | | | | | | | | | | | First, don't re-enable interrupts blindly in the Linux trap handler. We already handle page faults this way; synchronous interrupts like ILL_TRANS will fire even when interrupts are disabled, and we don't want to re-enable interrupts in that case. For ILL_TRANS, we now pass the ILL_VA_PC reason into the trap handler so we can report it properly; this is the address that caused the illegal translation trap. We print the address as part of the pr_alert() message now if it's coming from the kernel. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: add descriptive text if the kernel reports a bad trapChris Metcalf2012-05-251-2/+28
| | | | | | | | If the kernel unexpectedly takes a bad trap, it's convenient to have it report the type of trap as part of the error. This gives customers a bit more context before they call up customer support. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: fix up some minor trap handling issuesChris Metcalf2012-04-021-2/+7
| | | | | | | | | | We now respond to MEM_ERROR traps (e.g. an atomic instruction to non-cacheable memory) with a SIGBUS. We also no longer generate a console crash message if a user process die due to a SIGTRAP. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: work around a hardware issue with the return-address stackChris Metcalf2012-04-021-1/+5
| | | | | | | In certain circumstances we need to do a bunch of jump-and-link instructions to fill the hardware return-address stack with nonzero values. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* Disintegrate asm/system.h for TileDavid Howells2012-03-281-0/+1
| | | | | | | Disintegrate asm/system.h for Tile. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: factor out <arch/opcode.h> headerChris Metcalf2011-11-031-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | The kernel code was using some <asm> headers that included a mix of hardware-specific information (typically found in Tilera <arch> headers) and structures, enums, and function declarations supporting the disassembly function of the tile-desc.c sources. This change refactors that code so that a hardware-specific, but OS- and application-agnostic header, is created: <arch/opcode.h>. This header is then exported to userspace along with the other <arch> headers and can be used to build userspace code; in particular, it is used by glibc as part of implementing the backtrace() function. The new header, together with a header that specifically describes the disassembly code (<asm/tile-desc.h> with _32 and _64 variants), replaces the old <asm/opcode-tile*.h> and <asm/opcode_constants*.h> headers. As part of this change, we are also renaming the 32-bit constants from TILE_xxx to TILEPRO_xxx to better reflect the fact that they are specific to the TILEPro architecture, and not to TILE-Gx and any successor "tile" architecture chips. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: support signal "exception-trace" hookChris Metcalf2011-05-191-0/+1
| | | | | | | | | | | | | | | | This change adds support for /proc/sys/debug/exception-trace to tile. Like x86 and sparc, by default it is set to "1", generating a one-line printk whenever a user process crashes. By setting it to "2", we get a much more complete userspace diagnostic at crash time, including a user-space backtrace, register dump, and memory dump around the address of the crash. Some vestiges of the Tilera-internal version of this support are removed with this patch (the show_crashinfo variable and the arch_coredump_signal function). We retain a "crashinfo" boot parameter which allows you to set the boot-time value of exception-trace. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: enable single-step support for TILE-GxChris Metcalf2010-10-151-1/+1
| | | | | | | | | This is not quite the complete support, since we're not yet shipping intvec_64.S, but it is the support relevant to the set of files we are currently shipping, and makes it easier to track changes between our internal sources and our public GIT repository. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: parameterize system PLs to support KVM portChris Metcalf2010-10-151-1/+1
| | | | | | | | | While not a port to KVM (yet), this change modifies the kernel to be able to build either at PL1 or at PL2 with a suitable config switch. Pushing up this change avoids handling branch merge issues going forward with the KVM work. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: support backtracing on TILE-GxChris Metcalf2010-08-131-1/+3
| | | | | | | | | This functionality was stubbed out until recently. Now we support our normal backtracing API on TILE-Gx as well as on TILE64/TILEPro. This change includes a tweak to the instruction encoding caused by adding addxli for compat mode. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: Miscellaneous cleanup changes.Chris Metcalf2010-07-061-25/+105
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit is primarily changes caused by reviewing "sparse" and "checkpatch" output on our sources, so is somewhat noisy, since things like "printk() -> pr_err()" (or whatever) throughout the codebase tend to get tedious to read. Rather than trying to tease apart precisely which things changed due to which type of code review, this commit includes various cleanups in the code: - sparse: Add declarations in headers for globals. - sparse: Fix __user annotations. - sparse: Using gfp_t consistently instead of int. - sparse: removing functions not actually used. - checkpatch: Clean up printk() warnings by using pr_info(), etc.; also avoid partial-line printks except in bootup code. - checkpatch: Use exposed structs rather than typedefs. - checkpatch: Change some C99 comments to C89 comments. In addition, a couple of minor other changes are rolled in to this commit: - Add support for a "raise" instruction to cause SIGFPE, etc., to be raised. - Remove some compat code that is unnecessary when we fully eliminate some of the deprecated syscalls from the generic syscall ABI. - Update the tile_defconfig to reflect current config contents. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
* arch/tile: core support for Tilera 32-bit chips.Chris Metcalf2010-06-041-0/+237
This change is the core kernel support for TILEPro and TILE64 chips. No driver support (except the console driver) is included yet. This includes the relevant Linux headers in asm/; the low-level low-level "Tile architecture" headers in arch/, which are shared with the hypervisor, etc., and are build-system agnostic; and the relevant hypervisor headers in hv/. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Reviewed-by: Paul Mundt <lethal@linux-sh.org>
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