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2022-04-18ARC: fix typos in commentsJulia Lawall1-1/+1
Various spelling mistakes in comments. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr> Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2022-03-11resume_user_mode: Move to resume_user_mode.hEric W. Biederman1-2/+2
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>
2021-06-11ARCv2: save ABI registers across signal handlingVineet Gupta1-0/+43
ARCv2 has some configuration dependent registers (r30, r58, r59) which could be targetted by the compiler. To keep the ABI stable, these were unconditionally part of the glibc ABI (sysdeps/unix/sysv/linux/arc/sys/ucontext.h:mcontext_t) however we missed populating them (by saving/restoring them across signal handling). This patch fixes the issue by - adding arcv2 ABI regs to kernel struct sigcontext - populating them during signal handling Change to struct sigcontext might seem like a glibc ABI change (although it primarily uses ucontext_t:mcontext_t) but the fact is - it has only been extended (existing fields are not touched) - the old sigcontext was ABI incomplete to begin with anyways Fixes: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/53 Cc: <stable@vger.kernel.org> Tested-by: kernel test robot <lkp@intel.com> Reported-by: Vladimir Isaev <isaev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2021-05-10arc: Fix typos/spellosBhaskar Chowdhury1-2/+2
s/commiting/committing/ s/defintion/definition/ s/gaurantees/guarantees/ s/interrpted/interrupted/ s/interrutps/interrupts/ s/succeded/succeeded/ s/unconditonally/unconditionally/ Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2021-03-22arc: kernel: Return -EFAULT if copy_to_user() failsWang Qing1-2/+2
The copy_to_user() function returns the number of bytes remaining to be copied, but we want to return -EFAULT if the copy doesn't complete. Signed-off-by: Wang Qing <wangqing@vivo.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2020-11-09arc: add support for TIF_NOTIFY_SIGNALJens Axboe1-1/+1
Wire up TIF_NOTIFY_SIGNAL handling for arc. Cc: linux-snps-arc@lists.infradead.org Acked-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-18tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume()Jens Axboe1-1/+1
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>
2020-08-24treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva1-1/+1
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>
2019-07-09Merge branch 'siginfo-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull force_sig() argument change from Eric Biederman: "A source of error over the years has been that force_sig has taken a task parameter when it is only safe to use force_sig with the current task. The force_sig function is built for delivering synchronous signals such as SIGSEGV where the userspace application caused a synchronous fault (such as a page fault) and the kernel responded with a signal. Because the name force_sig does not make this clear, and because the force_sig takes a task parameter the function force_sig has been abused for sending other kinds of signals over the years. Slowly those have been fixed when the oopses have been tracked down. This set of changes fixes the remaining abusers of force_sig and carefully rips out the task parameter from force_sig and friends making this kind of error almost impossible in the future" * 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits) signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus signal: Remove the signal number and task parameters from force_sig_info signal: Factor force_sig_info_to_task out of force_sig_info signal: Generate the siginfo in force_sig signal: Move the computation of force into send_signal and correct it. signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal signal: Remove the task parameter from force_sig_fault signal: Use force_sig_fault_to_task for the two calls that don't deliver to current signal: Explicitly call force_sig_fault on current signal/unicore32: Remove tsk parameter from __do_user_fault signal/arm: Remove tsk parameter from __do_user_fault signal/arm: Remove tsk parameter from ptrace_break signal/nds32: Remove tsk parameter from send_sigtrap signal/riscv: Remove tsk parameter from do_trap signal/sh: Remove tsk parameter from force_sig_info_fault signal/um: Remove task parameter from send_sigtrap signal/x86: Remove task parameter from send_sigtrap signal: Remove task parameter from force_sig_mceerr signal: Remove task parameter from force_sig signal: Remove task parameter from force_sigsegv ...
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner1-4/+1
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-27signal: Remove task parameter from force_sigEric W. Biederman1-1/+1
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>
2019-01-04Remove 'type' argument from access_ok() functionLinus Torvalds1-2/+2
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>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar1-0/+2
<linux/sched/task_stack.h> We are going to split <linux/sched/task_stack.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/task_stack.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>
2016-09-16arc: don't leak bits of kernel stack into coredumpAl Viro1-4/+4
On faulting sigreturn we do get SIGSEGV, all right, but anything we'd put into pt_regs could end up in the coredump. And since __copy_from_user() never zeroed on arc, we'd better bugger off on its failure without copying random uninitialized bits of kernel stack into pt_regs... Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-30Fix typosAndrea Gelmini1-1/+1
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22ARCv2: Support for ARCv2 ISA and HS38x coresVineet Gupta1-3/+3
The notable features are: - SMP configurations of upto 4 cores with coherency - Optional L2 Cache and IO-Coherency - Revised Interrupt Architecture (multiple priorites, reg banks, auto stack switch, auto regfile save/restore) - MMUv4 (PIPT dcache, Huge Pages) - Instructions for * 64bit load/store: LDD, STD * Hardware assisted divide/remainder: DIV, REM * Function prologue/epilogue: ENTER_S, LEAVE_S * IRQ enable/disable: CLRI, SETI * pop count: FFS, FLS * SETcc, BMSKN, XBFU... Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19ARC: Make way for pt_regs != user_regs_structVineet Gupta1-2/+54
These have been register compatible so far. However ARCv2 mandates different pt_regs layout (due to h/w auto save). To keep pt_regs same for both, we start by removing the assumption - used mainly for block copies between the 2 structs in signal handling and ptrace Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-12arc: Remove signal translation and exec_domainRichard Weinberger1-13/+1
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>
2015-03-26ARC: signal handling robustifyVineet Gupta1-4/+16
A malicious signal handler / restorer can DOS the system by fudging the user regs saved on stack, causing weird things such as sigreturn returning to user mode PC but cpu state still being kernel mode.... Ensure that in sigreturn path status32 always has U bit; any other bogosity (gargbage PC etc) will be taken care of by normal user mode exceptions mechanisms. Reproducer signal handler: void handle_sig(int signo, siginfo_t *info, void *context) { ucontext_t *uc = context; struct user_regs_struct *regs = &(uc->uc_mcontext.regs); regs->scratch.status32 = 0; } Before the fix, kernel would go off to weeds like below: --------->8----------- [ARCLinux]$ ./signal-test Path: /signal-test CPU: 0 PID: 61 Comm: signal-test Not tainted 4.0.0-rc5+ #65 task: 8f177880 ti: 5ffe6000 task.ti: 8f15c000 [ECR ]: 0x00220200 => Invalid Write @ 0x00000010 by insn @ 0x00010698 [EFA ]: 0x00000010 [BLINK ]: 0x2007c1ee [ERET ]: 0x10698 [STAT32]: 0x00000000 : <-------- BTA: 0x00010680 SP: 0x5ffe7e48 FP: 0x00000000 LPS: 0x20003c6c LPE: 0x20003c70 LPC: 0x00000000 ... --------->8----------- Reported-by: Alexey Brodkin <abrodkin@synopsys.com> Cc: <stable@vger.kernel.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-03-26ARC: SA_SIGINFO ucontext regs off-by-oneVineet Gupta1-2/+2
The regfile provided to SA_SIGINFO signal handler as ucontext was off by one due to pt_regs gutter cleanups in 2013. Before handling signal, user pt_regs are copied onto user_regs_struct and copied back later. Both structs are binary compatible. This was all fine until commit 2fa919045b72 (ARC: pt_regs update #2) which removed the empty stack slot at top of pt_regs (corresponding to first pad) and made the corresponding fixup in struct user_regs_struct (the pad in there was moved out of @scratch - not removed altogether as it is part of ptrace ABI) struct user_regs_struct { + long pad; struct { - long pad; long bta, lp_start, lp_end,.... } scratch; ... } This meant that now user_regs_struct was off by 1 reg w.r.t pt_regs and signal code needs to user_regs_struct.scratch to reflect it as pt_regs, which is what this commit does. This problem was hidden for 2 years, because both save/restore, despite using wrong location, were using the same location. Only an interim inspection (reproducer below) exposed the issue. void handle_segv(int signo, siginfo_t *info, void *context) { ucontext_t *uc = context; struct user_regs_struct *regs = &(uc->uc_mcontext.regs); printf("regs %x %x\n", <=== prints 7 8 (vs. 8 9) regs->scratch.r8, regs->scratch.r9); } int main() { struct sigaction sa; sa.sa_sigaction = handle_segv; sa.sa_flags = SA_SIGINFO; sigemptyset(&sa.sa_mask); sigaction(SIGSEGV, &sa, NULL); asm volatile( "mov r7, 7 \n" "mov r8, 8 \n" "mov r9, 9 \n" "mov r10, 10 \n" :::"r7","r8","r9","r10"); *((unsigned int*)0x10) = 0; } Fixes: 2fa919045b72ec892e "ARC: pt_regs update #2: Remove unused gutter at start of pt_regs" CC: <stable@vger.kernel.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-13all arches, signal: move restart_block to struct task_structAndy Lutomirski1-1/+1
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>
2014-08-06arc: Use sigsp()Richard Weinberger1-7/+3
Use sigsp() instead of the open coded variant. Signed-off-by: Richard Weinberger <richard@nod.at> Acked-by: Vineet Gupta <vgupta@synopsys.com>
2014-08-06arc: Use get_signal() signal_setup_done()Richard Weinberger1-24/+15
Use the more generic functions get_signal() signal_setup_done() for signal delivery. Signed-off-by: Richard Weinberger <richard@nod.at> Acked-by: Vineet Gupta <vgupta@synopsys.com>
2013-10-03ARC: Fix signal frame management for SA_SIGINFOChristian Ruppert1-12/+13
Previously, when a signal was registered with SA_SIGINFO, parameters 2 and 3 of the signal handler were written to registers r1 and r2 before the register set was saved. This led to corruption of these two registers after returning from the signal handler (the wrong values were restored). With this patch, registers are now saved before any parameters are passed, thus maintaining the processor state from before signal entry. Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15ARC: [Review] Prevent incorrect syscall restartsVineet Gupta1-4/+8
Per Al Viro's "signals for dummies" https://lkml.org/lkml/2012/12/6/366 there are 3 golden rules for (not) restarting syscalls: " What we need to guarantee is * restarts do not happen on signals caught in interrupts or exceptions * restarts do not happen on signals caught in sigreturn() * restart should happen only once, even if we get through do_signal() many times." ARC Port already handled #1, this patch fixes #2 and #3. We use the additional state in pt_regs->orig_r8 to ckh if restarting has already been done once. Thanks to Al Viro for spotting this. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Al Viro <viro@ZenIV.linux.org.uk>
2013-02-15ARC: Signal handlingVineet Gupta1-0/+356
Includes following fixes courtesy review by Al-Viro * Tracer poke to Callee-regs were lost Before going off into do_signal( ) we save the user-mode callee regs (as they are not saved by default as part of pt_regs). This is to make sure that that a Tracer (if tracing related signal) is able to do likes of PEEKUSR(callee-reg). However in return path we were simply discarding the user-mode callee regs, which would break a POKEUSR(callee-reg) from a tracer. * Issue related to multiple syscall restarts are addressed in next patch Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Acked-by: Jonas Bonn <jonas@southpole.se>