kernel.git/arch/arc/kernel/signal.c, branch linux-5.2.y

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

2019-06-19T15:09:55Z

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 Reviewed-by: Enrico Weigelt Reviewed-by: Kate Stewart Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman

Remove 'type' argument from access_ok() function

2019-01-04T02:57:57Z

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

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:36Z

We are going to split out of , which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder file that just maps to 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 Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

arc: don't leak bits of kernel stack into coredump

2016-09-15T23:51:55Z

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

Fix typos

2016-05-30T04:37:32Z

Signed-off-by: Andrea Gelmini Signed-off-by: Vineet Gupta

ARCv2: Support for ARCv2 ISA and HS38x cores

2015-06-22T08:36:55Z

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

ARC: Make way for pt_regs != user_regs_struct

2015-06-19T12:39:40Z

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

arc: Remove signal translation and exec_domain

2015-04-12T19:03:30Z

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

ARC: signal handling robustify

2015-03-26T05:49:36Z

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 Cc: Signed-off-by: Vineet Gupta

ARC: SA_SIGINFO ucontext regs off-by-one

2015-03-26T04:08:00Z

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: Signed-off-by: Vineet Gupta