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2023-10-06m68k: kernel: Add and use "signal.h"Geert Uytterhoeven
When building with W=1: arch/m68k/kernel/signal.c:756:18: warning: no previous prototype for ‘do_sigreturn’ [-Wmissing-prototypes] 756 | asmlinkage void *do_sigreturn(struct pt_regs *regs, struct switch_stack *sw) | ^~~~~~~~~~~~ arch/m68k/kernel/signal.c:783:18: warning: no previous prototype for ‘do_rt_sigreturn’ [-Wmissing-prototypes] 783 | asmlinkage void *do_rt_sigreturn(struct pt_regs *regs, struct switch_stack *sw) | ^~~~~~~~~~~~~~~ arch/m68k/kernel/signal.c:1112:17: warning: no previous prototype for ‘do_notify_resume’ [-Wmissing-prototypes] 1112 | asmlinkage void do_notify_resume(struct pt_regs *regs) | ^~~~~~~~~~~~~~~~ Fix this by introducing a new header file "signal.h" for holding the prototypes of functions implemented in arch/m68k/kernel/signal.c. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/25cecda80698829cec18721a9d0f058cc69df0cc.1694613528.git.geert@linux-m68k.org
2023-10-06m68k: kernel: Add missing asmlinkage to do_notify_resume()Geert Uytterhoeven
do_notify_resume() is called from assembly code, so it should be marked asmlinkage for documentation purposes. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/e24d63ec4332316e859125caa8d07c0589603cfd.1694613528.git.geert@linux-m68k.org
2023-05-22m68k: Move signal frame following exception on 68020/030Finn Thain
On 68030/020, an instruction such as, moveml %a2-%a3/%a5,%sp@- may cause a stack page fault during instruction execution (i.e. not at an instruction boundary) and produce a format 0xB exception frame. In this situation, the value of USP will be unreliable. If a signal is to be delivered following the exception, this USP value is used to calculate the location for a signal frame. This can result in a corrupted user stack. The corruption was detected in dash (actually in glibc) where it showed up as an intermittent "stack smashing detected" message and crash following signal delivery for SIGCHLD. It was hard to reproduce that failure because delivery of the signal raced with the page fault and because the kernel places an unpredictable gap of up to 7 bytes between the USP and the signal frame. A format 0xB exception frame can be produced by a bus error or an address error. The 68030 Users Manual says that address errors occur immediately upon detection during instruction prefetch. The instruction pipeline allows prefetch to overlap with other instructions, which means an address error can arise during the execution of a different instruction. So it seems likely that this patch may help in the address error case also. Reported-and-tested-by: Stan Johnson <userm57@yahoo.com> Link: https://lore.kernel.org/all/CAMuHMdW3yD22_ApemzW_6me3adq6A458u1_F0v-1EYwK_62jPA@mail.gmail.com/ Cc: Michael Schmitz <schmitzmic@gmail.com> Cc: Andreas Schwab <schwab@linux-m68k.org> Cc: stable@vger.kernel.org Co-developed-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Finn Thain <fthain@linux-m68k.org> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Link: https://lore.kernel.org/r/9e66262a754fcba50208aa424188896cc52a1dd1.1683365892.git.fthain@linux-m68k.org Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2022-04-22signal: Deliver SIGTRAP on perf event asynchronously if blockedMarco Elver
With SIGTRAP on perf events, we have encountered termination of processes due to user space attempting to block delivery of SIGTRAP. Consider this case: <set up SIGTRAP on a perf event> ... sigset_t s; sigemptyset(&s); sigaddset(&s, SIGTRAP | <and others>); sigprocmask(SIG_BLOCK, &s, ...); ... <perf event triggers> When the perf event triggers, while SIGTRAP is blocked, force_sig_perf() will force the signal, but revert back to the default handler, thus terminating the task. This makes sense for error conditions, but not so much for explicitly requested monitoring. However, the expectation is still that signals generated by perf events are synchronous, which will no longer be the case if the signal is blocked and delivered later. To give user space the ability to clearly distinguish synchronous from asynchronous signals, introduce siginfo_t::si_perf_flags and TRAP_PERF_FLAG_ASYNC (opted for flags in case more binary information is required in future). The resolution to the problem is then to (a) no longer force the signal (avoiding the terminations), but (b) tell user space via si_perf_flags if the signal was synchronous or not, so that such signals can be handled differently (e.g. let user space decide to ignore or consider the data imprecise). The alternative of making the kernel ignore SIGTRAP on perf events if the signal is blocked may work for some usecases, but likely causes issues in others that then have to revert back to interception of sigprocmask() (which we want to avoid). [ A concrete example: when using breakpoint perf events to track data-flow, in a region of code where signals are blocked, data-flow can no longer be tracked accurately. When a relevant asynchronous signal is received after unblocking the signal, the data-flow tracking logic needs to know its state is imprecise. ] Fixes: 97ba62b27867 ("perf: Add support for SIGTRAP on perf events") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Dmitry Vyukov <dvyukov@google.com> Link: https://lore.kernel.org/r/20220404111204.935357-1-elver@google.com
2022-03-10resume_user_mode: Move to resume_user_mode.hEric W. Biederman
Move set_notify_resume and tracehook_notify_resume into resume_user_mode.h. While doing that rename tracehook_notify_resume to resume_user_mode_work. Update all of the places that included tracehook.h for these functions to include resume_user_mode.h instead. Update all of the callers of tracehook_notify_resume to call resume_user_mode_work. Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20220309162454.123006-12-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-09-24m68k: Leave stack mangling to asm wrapper of sigreturn()Al Viro
sigreturn has to deal with an unpleasant problem - exception stack frames have different sizes, depending upon the exception (and processor model, as well) and variable-sized part of exception frame may contain information needed for instruction restart. So when signal handler terminates and calls sigreturn to resume the execution at the place where we'd been when we caught the signal, it has to rearrange the frame at the bottom of kernel stack. Worse, it might need to open a gap in the kernel stack, shifting pt_regs towards lower addresses. Doing that from C is insane - we'd need to shift stack frames (return addresses, local variables, etc.) of C call chain, right under the nose of compiler and hope it won't fall apart horribly. What had been actually done is only slightly less insane - an inline asm in mangle_kernel_stack() moved the stuff around, then reset stack pointer and jumped to label in asm glue. However, we can avoid all that mess if the asm wrapper we have to use anyway would reserve some space on the stack between switch_stack and the C stack frame of do_{rt_,}sigreturn(). Then C part can simply memmove() pt_regs + switch_stack, memcpy() the variable part of exception frame into the opened gap - all of that without inline asm, buggering C call chain, magical jumps to asm labels, etc. Asm wrapper would need to know where the moved switch_stack has ended up - it might have been shifted into the gap we'd reserved before do_rt_sigreturn() call. That's where it needs to set the stack pointer to. So let the C part return just that and be done with that. While we are at it, the call of berr_040cleanup() we need to do when returning via 68040 bus error exception frame can be moved into C part as well. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Reviewed-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Finn Thain <fthain@linux-m68k.org> Link: https://lore.kernel.org/r/YP2dTQPm1wGPWFgD@zeniv-ca.linux.org.uk Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2021-09-24m68k: Handle arrivals of multiple signals correctlyAl Viro
When we have several pending signals, have entered with the kernel with large exception frame *and* have already built at least one sigframe, regs->stkadj is going to be non-zero and regs->format/sr/pc are going to be junk - the real values are in shifted exception stack frame we'd built when putting together the first sigframe. If that happens, subsequent sigframes are going to be garbage. Not hard to fix - just need to find the "adjusted" frame first and look for format/vector/sr/pc in it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Reviewed-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Finn Thain <fthain@linux-m68k.org> Link: https://lore.kernel.org/r/YP2dBIAPTaVvHiZ6@zeniv-ca.linux.org.uk Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2021-05-18signal: Deliver all of the siginfo perf data in _perfEric W. Biederman
Don't abuse si_errno and deliver all of the perf data in _perf member of siginfo_t. Note: The data field in the perf data structures in a u64 to allow a pointer to be encoded without needed to implement a 32bit and 64bit version of the same structure. There already exists a 32bit and 64bit versions siginfo_t, and the 32bit version can not include a 64bit member as it only has 32bit alignment. So unsigned long is used in siginfo_t instead of a u64 as unsigned long can encode a pointer on all architectures linux supports. v1: https://lkml.kernel.org/r/m11rarqqx2.fsf_-_@fess.ebiederm.org v2: https://lkml.kernel.org/r/20210503203814.25487-10-ebiederm@xmission.com v3: https://lkml.kernel.org/r/20210505141101.11519-11-ebiederm@xmission.com Link: https://lkml.kernel.org/r/20210517195748.8880-4-ebiederm@xmission.com Reviewed-by: Marco Elver <elver@google.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-04-16signal: Introduce TRAP_PERF si_code and si_perf to siginfoMarco Elver
Introduces the TRAP_PERF si_code, and associated siginfo_t field si_perf. These will be used by the perf event subsystem to send signals (if requested) to the task where an event occurred. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k Acked-by: Arnd Bergmann <arnd@arndb.de> # asm-generic Link: https://lkml.kernel.org/r/20210408103605.1676875-6-elver@google.com
2020-11-09m68k: add support for TIF_NOTIFY_SIGNALJens Axboe
Wire up TIF_NOTIFY_SIGNAL handling for m68k. Cc: linux-m68k@lists.linux-m68k.org Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-23Merge tag 'arch-cleanup-2020-10-22' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull arch task_work cleanups from Jens Axboe: "Two cleanups that don't fit other categories: - Finally get the task_work_add() cleanup done properly, so we don't have random 0/1/false/true/TWA_SIGNAL confusing use cases. Updates all callers, and also fixes up the documentation for task_work_add(). - While working on some TIF related changes for 5.11, this TIF_NOTIFY_RESUME cleanup fell out of that. Remove some arch duplication for how that is handled" * tag 'arch-cleanup-2020-10-22' of git://git.kernel.dk/linux-block: task_work: cleanup notification modes tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume()
2020-10-17tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume()Jens Axboe
All the callers currently do this, clean it up and move the clearing into tracehook_notify_resume() instead. Reviewed-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-05m68knommu: fix sparse warnings in signal codeGreg Ungerer
Commit 858b810bf63f ("m68knommu: switch to using asm-generic/uaccess.h") cleaned up a number of sparse warnings associated with lack of __user annotations. It also uncovered a couple of more in the signal handling code: arch/m68k/kernel/signal.c:923:16: expected char [noderef] __user *__x arch/m68k/kernel/signal.c:923:16: got void * arch/m68k/kernel/signal.c:1007:16: warning: incorrect type in initializer (different address spaces) arch/m68k/kernel/signal.c:1007:16: expected char [noderef] __user *__x arch/m68k/kernel/signal.c:1007:16: got void * arch/m68k/kernel/signal.c:1132:6: warning: symbol 'do_notify_resume' was not declared. Should it be static? These are specific to a non-MMU configuration. Fix these inserting the correct __user annotations as required. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-07-13m68k: Use sizeof_field() helperGustavo A. R. Silva
Make use of the sizeof_field() helper instead of an open-coded version. Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/20200527133942.GA10408@embeddedor Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2020-06-09mm: don't include asm/pgtable.h if linux/mm.h is already includedMike Rapoport
Patch series "mm: consolidate definitions of page table accessors", v2. The low level page table accessors (pXY_index(), pXY_offset()) are duplicated across all architectures and sometimes more than once. For instance, we have 31 definition of pgd_offset() for 25 supported architectures. Most of these definitions are actually identical and typically it boils down to, e.g. static inline unsigned long pmd_index(unsigned long address) { return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1); } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address); } These definitions can be shared among 90% of the arches provided XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined. For architectures that really need a custom version there is always possibility to override the generic version with the usual ifdefs magic. These patches introduce include/linux/pgtable.h that replaces include/asm-generic/pgtable.h and add the definitions of the page table accessors to the new header. This patch (of 12): The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the functions involving page table manipulations, e.g. pte_alloc() and pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h> in the files that include <linux/mm.h>. The include statements in such cases are remove with a simple loop: for f in $(git grep -l "include <linux/mm.h>") ; do sed -i -e '/include <asm\/pgtable.h>/ d' $f done Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-27signal: Remove task parameter from force_sigEric W. Biederman
All of the remaining callers pass current into force_sig so remove the task parameter to make this obvious and to make misuse more difficult in the future. This also makes it clear force_sig passes current into force_sig_info. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2019-01-21m68k: Avoid VLA use in mangle_kernel_stack()Geert Uytterhoeven
With gcc 7.3.0: arch/m68k/kernel/signal.c: In function ‘mangle_kernel_stack’: arch/m68k/kernel/signal.c:654:3: warning: ISO C90 forbids variable length array ‘buf’ [-Wvla] unsigned long buf[fsize / 2]; /* yes, twice as much */ ^~~~~~~~ Replace the variable size by the upper limit, which is 168 bytes. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Arnd Bergmann <arnd@arndb.de>
2019-01-03Remove 'type' argument from access_ok() functionLinus Torvalds
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-05-22m68k: Fix style, spelling, and grammar in siginfo_build_tests()Geert Uytterhoeven
Fixes: 4be33329d46f80e8 ("m68k: Verify the offsets in struct siginfo never change.") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2018-04-02m68k: Verify the offsets in struct siginfo never change.Eric W. Biederman
A change to the generic struct siginfo accidentally changed the offset of si_offset. Add build time checks to ensure the offsets of all known fields in struct siginfo never change. This copies the form of similar changes on x86. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-06-19m68k: Remove ptrace_signal_deliverAndreas Schwab
This fixes debugger syscall restart interactions. A debugger that modifies the tracee's program counter is expected to set the orig_d0 pseudo register to -1, to disable a possible syscall restart. This removes the last user of the ptrace_signal_deliver hook in the ptrace signal handling, so remove that as well. Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2017-03-28m68k: switch to generic extable.hAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-02-12m68k/kernel: Modernize printing of kernel messagesGeert Uytterhoeven
- Use pr_err_ratelimited() instead of deprecated printk_ratelimit(), - Add dummies for validating format strings when debugging is disabled, - Convert from printk() to pr_*(), - Correct printf()-style format specifiers. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds
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>
2016-10-03Merge tag 'm68k-for-v4.9-tag1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k Pull m68k updates from Geert Uytterhoeven: - cleanups - defconfig updates - GPG fingerprint update * tag 'm68k-for-v4.9-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k: m68k: Migrate exception table users off module.h and onto extable.h CREDITS: Update fingerprint for Geert Uytterhoeven m68k: Use IS_ENABLED() instead of checking for built-in or module m68k/defconfig: Update defconfigs for v4.8-rc1
2016-09-30m68k: Migrate exception table users off module.h and onto extable.hPaul Gortmaker
This file was only including module.h for exception table related functions. We've now separated that content out into its own file "extable.h" so now move over to that and avoid all the extra header content in module.h that we don't really need to compile this. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2016-08-08m68knommu: fix user a5 register being overwrittenGreg Ungerer
On no-MMU systems the application a5 register can be overwitten with the address of the process data segment when processing application signals. For flat format applications compiled with full absolute relocation this effectively corrupts the a5 register on signal processing - and this very quickly leads to process crash and often takes out the whole system with a panic as well. This has no effect on flat format applications compiled with the more common PIC methods (such as -msep-data). These format applications reserve a5 for the pointer to the data segment anyway - so it doesn't change it. A long time ago the a5 register was used in the code packed into the user stack to enable signal return processing. And so it had to be restored on end of signal cleanup processing back to the original a5 user value. This was historically done by saving away a5 in the sigcontext structure. At some point (a long time back it seems) the a5 restore process was changed and it was hard coded to put the user data segment address directly into a5. Which is ok for the common PIC compiled application case, but breaks the full relocation application code. We no longer use this type of signal handling mechanism and so we don't need to do anything special to save and restore a5 at all now. So remove the code that hard codes a5 to the address of the user data segment. Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2016-02-29m68k: Use conventional function parameters for do_sigreturnGreg Ungerer
Create conventional stack parameters for the calls to do_sigreturn and do_rt_sigreturn. The current C code for do_sigreturn and do_rt_sigreturn dig into the stack to create local pointers to the saved switch stack and the pt_regs structs. The motivation for this change is a problem with non-MMU targets that have broken signal return paths on newer versions of gcc. It appears as though gcc has determined that the pointers into the saved stack structs, and the saved structs themselves, are function parameters and updates to them will be lost on function return, so they are optimized away. This results in large parts of restore_sigcontext() and mangle_kernel_stack() functions being removed. Of course this results in non-functional code causing kernel oops. This problem has been observed with gcc version 5.2 and 5.3, and probably exists in earlier versions as well. Using conventional stack parameter pointers passed to these functions has the advantage of the code here not needing to know the exact details of how the underlying entry handler layed these structs out on the stack. So the rather ugly pointer setup casting and arg referencing can be removed. The resulting code after this change is a few bytes larger (due to the overhead of creating the stack args and their tear down). Not being hot paths I don't think this is too much of a problem here. An alternative solution is to put a barrier() in the do_sigreturn() code, but this doesn't feel quite as clean as this solution. This change has been compile tested on all defconfigs, and run tested on Atari (through aranym), ColdFire with MMU (M5407EVB) and ColdFire with no-MMU (QEMU and M5208EVB). Signed-off-by: Greg Ungerer <gerg@uclinux.org> Acked-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2015-04-12m68k: Remove signal translation and exec_domainRichard Weinberger
As execution domain support is gone we can remove signal translation from the signal code and remove exec_domain from thread_info. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-02-12all arches, signal: move restart_block to struct task_structAndy Lutomirski
If an attacker can cause a controlled kernel stack overflow, overwriting the restart block is a very juicy exploit target. This is because the restart_block is held in the same memory allocation as the kernel stack. Moving the restart block to struct task_struct prevents this exploit by making the restart_block harder to locate. Note that there are other fields in thread_info that are also easy targets, at least on some architectures. It's also a decent simplification, since the restart code is more or less identical on all architectures. [james.hogan@imgtec.com: metag: align thread_info::supervisor_stack] Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: David Miller <davem@davemloft.net> Acked-by: Richard Weinberger <richard@nod.at> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Steven Miao <realmz6@gmail.com> Cc: Mark Salter <msalter@redhat.com> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: David Howells <dhowells@redhat.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chen Liqin <liqin.linux@gmail.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06m68k: Use sigsp()Richard Weinberger
Use sigsp() instead of the open coded variant. Signed-off-by: Richard Weinberger <richard@nod.at>
2014-08-06m68k: Use get_signal() signal_setup_done()Richard Weinberger
Use the more generic functions get_signal() signal_setup_done() for signal delivery. Signed-off-by: Richard Weinberger <richard@nod.at>
2013-08-26m68k/coldfire: flush cache when creating the signal stack frameAlexander Stein
When the signal stack frame is created, it must be flushed in order to make sure the cache fetches the correct data. Without cache flush the icache might pick up old cached data from an older signal stack frame if the signal is raised again very fast. In case of copyback the data cache muist be pushed first, but is untested. Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Greg Ungerer <gerg@uclinux.org>
2013-02-03m68k: switch to generic old sigaction()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-03m68k: switch to generic old sigsuspendAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-03m68k: switch to generic sigaltstackAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-29get rid of ptrace_signal_deliver() argumentsAl Viro
the first one is equal to signal_pt_regs(), the second is never used (and always NULL, while we are at it). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>
2012-06-01most 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>
2012-05-21m68k: add TIF_NOTIFY_RESUME and handle it.Al Viro
TIF_NOTIFY_RESUME added (as bit 5). That way nommu glue needs no changes at all; mmu one needs just to replace jmi do_signal_return to jne do_signal_return There we have flags shifted up, until bit 6 (SIGPENDING) is in MSBit; instead of checking that MSBit is set (jmi) we check that MSBit or something below it is set (jne); bits 0..4 are never set, so that's precisely "bit 6 or bit 5 is set". Usual handling of NOTIFY_RESUME/SIGPENDING is done in do_notify_resume(); glue calls it instead of do_signal(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-21m68k: 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. Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Greg Ungerer <gerg@uclinux.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-21new helper: sigsuspend()Al Viro
guts of saved_sigmask-based sigsuspend/rt_sigsuspend. Takes kernel sigset_t *. Open-coded instances replaced with calling it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-20m68k: merge the MMU and non-MMU signal.c codeGreg Ungerer
The MMU (signal_mm.c) and non-MMU (signal_no.c) versions of the m68k architecture signal handling code are very similar. Most of their code is the same. Merge the two back into a single signal.c, and move some of the code around inside the file to minimize the number of #ifdefs required. Specificially we can group out the CONFIG_FPU and the CONFIG_MMU code. We end up needing a few other "#ifdef CONFIG_MMU" as well, but not too many. Signed-off-by: Greg Ungerer <gerg@uclinux.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
2011-03-25m68k: merge m68k and m68knommu arch directoriesGreg Ungerer
There is a lot of common code that could be shared between the m68k and m68knommu arch branches. It makes sense to merge the two branches into a single directory structure so that we can more easily share that common code. This is a brute force merge, based on a script from Stephen King <sfking@fdwdc.com>, which was originally written by Arnd Bergmann <arnd@arndb.de>. > The script was inspired by the script Sam Ravnborg used to merge the > includes from m68knommu. For those files common to both arches but > differing in content, the m68k version of the file is renamed to > <file>_mm.<ext> and the m68knommu version of the file is moved into the > corresponding m68k directory and renamed <file>_no.<ext> and a small > wrapper file <file>.<ext> is used to select between the two version. Files > that are common to both but don't differ are removed from the m68knommu > tree and files and directories that are unique to the m68knommu tree are > moved to the m68k tree. Finally, the arch/m68knommu tree is removed. > > To select between the the versions of the files, the wrapper uses > > #ifdef CONFIG_MMU > #include <file>_mm.<ext> > #else > #include <file>_no.<ext> > #endif On top of this file merge I have done a simplistic merge of m68k and m68knommu Kconfig, which primarily attempts to keep existing options and menus in place. Other than a handful of options being moved it produces identical .config outputs on m68k and m68knommu targets I tested it on. With this in place there is now quite a bit of scope for merge cleanups in future patches. Signed-off-by: Greg Ungerer <gerg@uclinux.org>
2011-03-16m68k: Add helper function handle_kernel_fault()Roman Zippel
Add helper function handle_kernel_fault() in signal.c, so frame_extra_sizes can become static, and to avoid future code duplication. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>