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![Eric W. Biederman](/assets/img/avatar_default.png)
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>
957 lines
23 KiB
C
957 lines
23 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright (C) 1994 - 2000 Ralf Baechle
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* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
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* Copyright (C) 2014, Imagination Technologies Ltd.
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*/
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#include <linux/cache.h>
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#include <linux/context_tracking.h>
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#include <linux/irqflags.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/personality.h>
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#include <linux/smp.h>
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#include <linux/kernel.h>
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#include <linux/signal.h>
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#include <linux/errno.h>
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#include <linux/wait.h>
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#include <linux/ptrace.h>
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#include <linux/unistd.h>
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#include <linux/uprobes.h>
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#include <linux/compiler.h>
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#include <linux/syscalls.h>
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#include <linux/uaccess.h>
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#include <linux/tracehook.h>
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#include <asm/abi.h>
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#include <asm/asm.h>
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#include <linux/bitops.h>
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#include <asm/cacheflush.h>
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#include <asm/fpu.h>
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#include <asm/sim.h>
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#include <asm/ucontext.h>
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#include <asm/cpu-features.h>
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#include <asm/war.h>
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#include <asm/dsp.h>
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#include <asm/inst.h>
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#include <asm/msa.h>
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#include "signal-common.h"
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static int (*save_fp_context)(void __user *sc);
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static int (*restore_fp_context)(void __user *sc);
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struct sigframe {
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u32 sf_ass[4]; /* argument save space for o32 */
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u32 sf_pad[2]; /* Was: signal trampoline */
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/* Matches struct ucontext from its uc_mcontext field onwards */
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struct sigcontext sf_sc;
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sigset_t sf_mask;
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unsigned long long sf_extcontext[0];
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};
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struct rt_sigframe {
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u32 rs_ass[4]; /* argument save space for o32 */
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u32 rs_pad[2]; /* Was: signal trampoline */
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struct siginfo rs_info;
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struct ucontext rs_uc;
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};
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#ifdef CONFIG_MIPS_FP_SUPPORT
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/*
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* Thread saved context copy to/from a signal context presumed to be on the
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* user stack, and therefore accessed with appropriate macros from uaccess.h.
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*/
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static int copy_fp_to_sigcontext(void __user *sc)
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{
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struct mips_abi *abi = current->thread.abi;
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uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
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uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
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int i;
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int err = 0;
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int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
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for (i = 0; i < NUM_FPU_REGS; i += inc) {
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err |=
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__put_user(get_fpr64(¤t->thread.fpu.fpr[i], 0),
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&fpregs[i]);
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}
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err |= __put_user(current->thread.fpu.fcr31, csr);
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return err;
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}
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static int copy_fp_from_sigcontext(void __user *sc)
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{
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struct mips_abi *abi = current->thread.abi;
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uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
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uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
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int i;
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int err = 0;
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int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
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u64 fpr_val;
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for (i = 0; i < NUM_FPU_REGS; i += inc) {
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err |= __get_user(fpr_val, &fpregs[i]);
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set_fpr64(¤t->thread.fpu.fpr[i], 0, fpr_val);
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}
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err |= __get_user(current->thread.fpu.fcr31, csr);
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return err;
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}
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#else /* !CONFIG_MIPS_FP_SUPPORT */
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static int copy_fp_to_sigcontext(void __user *sc)
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{
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return 0;
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}
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static int copy_fp_from_sigcontext(void __user *sc)
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{
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return 0;
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}
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#endif /* !CONFIG_MIPS_FP_SUPPORT */
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/*
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* Wrappers for the assembly _{save,restore}_fp_context functions.
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*/
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static int save_hw_fp_context(void __user *sc)
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{
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struct mips_abi *abi = current->thread.abi;
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uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
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uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
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return _save_fp_context(fpregs, csr);
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}
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static int restore_hw_fp_context(void __user *sc)
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{
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struct mips_abi *abi = current->thread.abi;
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uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
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uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
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return _restore_fp_context(fpregs, csr);
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}
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/*
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* Extended context handling.
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*/
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static inline void __user *sc_to_extcontext(void __user *sc)
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{
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struct ucontext __user *uc;
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/*
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* We can just pretend the sigcontext is always embedded in a struct
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* ucontext here, because the offset from sigcontext to extended
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* context is the same in the struct sigframe case.
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*/
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uc = container_of(sc, struct ucontext, uc_mcontext);
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return &uc->uc_extcontext;
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}
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#ifdef CONFIG_CPU_HAS_MSA
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static int save_msa_extcontext(void __user *buf)
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{
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struct msa_extcontext __user *msa = buf;
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uint64_t val;
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int i, err;
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if (!thread_msa_context_live())
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return 0;
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/*
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* Ensure that we can't lose the live MSA context between checking
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* for it & writing it to memory.
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*/
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preempt_disable();
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if (is_msa_enabled()) {
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/*
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* There are no EVA versions of the vector register load/store
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* instructions, so MSA context has to be saved to kernel memory
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* and then copied to user memory. The save to kernel memory
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* should already have been done when handling scalar FP
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* context.
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*/
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BUG_ON(IS_ENABLED(CONFIG_EVA));
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err = __put_user(read_msa_csr(), &msa->csr);
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err |= _save_msa_all_upper(&msa->wr);
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preempt_enable();
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} else {
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preempt_enable();
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err = __put_user(current->thread.fpu.msacsr, &msa->csr);
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for (i = 0; i < NUM_FPU_REGS; i++) {
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val = get_fpr64(¤t->thread.fpu.fpr[i], 1);
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err |= __put_user(val, &msa->wr[i]);
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}
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}
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err |= __put_user(MSA_EXTCONTEXT_MAGIC, &msa->ext.magic);
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err |= __put_user(sizeof(*msa), &msa->ext.size);
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return err ? -EFAULT : sizeof(*msa);
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}
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static int restore_msa_extcontext(void __user *buf, unsigned int size)
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{
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struct msa_extcontext __user *msa = buf;
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unsigned long long val;
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unsigned int csr;
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int i, err;
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if (size != sizeof(*msa))
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return -EINVAL;
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err = get_user(csr, &msa->csr);
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if (err)
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return err;
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preempt_disable();
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if (is_msa_enabled()) {
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/*
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* There are no EVA versions of the vector register load/store
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* instructions, so MSA context has to be copied to kernel
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* memory and later loaded to registers. The same is true of
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* scalar FP context, so FPU & MSA should have already been
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* disabled whilst handling scalar FP context.
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*/
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BUG_ON(IS_ENABLED(CONFIG_EVA));
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write_msa_csr(csr);
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err |= _restore_msa_all_upper(&msa->wr);
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preempt_enable();
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} else {
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preempt_enable();
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current->thread.fpu.msacsr = csr;
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for (i = 0; i < NUM_FPU_REGS; i++) {
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err |= __get_user(val, &msa->wr[i]);
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set_fpr64(¤t->thread.fpu.fpr[i], 1, val);
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}
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}
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return err;
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}
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#else /* !CONFIG_CPU_HAS_MSA */
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static int save_msa_extcontext(void __user *buf)
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{
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return 0;
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}
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static int restore_msa_extcontext(void __user *buf, unsigned int size)
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{
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return SIGSYS;
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}
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#endif /* !CONFIG_CPU_HAS_MSA */
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static int save_extcontext(void __user *buf)
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{
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int sz;
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sz = save_msa_extcontext(buf);
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if (sz < 0)
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return sz;
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buf += sz;
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/* If no context was saved then trivially return */
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if (!sz)
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return 0;
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/* Write the end marker */
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if (__put_user(END_EXTCONTEXT_MAGIC, (u32 *)buf))
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return -EFAULT;
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sz += sizeof(((struct extcontext *)NULL)->magic);
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return sz;
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}
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static int restore_extcontext(void __user *buf)
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{
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struct extcontext ext;
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int err;
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while (1) {
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err = __get_user(ext.magic, (unsigned int *)buf);
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if (err)
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return err;
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if (ext.magic == END_EXTCONTEXT_MAGIC)
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return 0;
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err = __get_user(ext.size, (unsigned int *)(buf
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+ offsetof(struct extcontext, size)));
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if (err)
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return err;
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switch (ext.magic) {
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case MSA_EXTCONTEXT_MAGIC:
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err = restore_msa_extcontext(buf, ext.size);
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break;
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default:
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err = -EINVAL;
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break;
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}
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if (err)
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return err;
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buf += ext.size;
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}
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}
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/*
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* Helper routines
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*/
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int protected_save_fp_context(void __user *sc)
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{
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struct mips_abi *abi = current->thread.abi;
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uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
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uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
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uint32_t __user *used_math = sc + abi->off_sc_used_math;
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unsigned int used, ext_sz;
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int err;
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used = used_math() ? USED_FP : 0;
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if (!used)
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goto fp_done;
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if (!test_thread_flag(TIF_32BIT_FPREGS))
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used |= USED_FR1;
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if (test_thread_flag(TIF_HYBRID_FPREGS))
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used |= USED_HYBRID_FPRS;
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/*
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* EVA does not have userland equivalents of ldc1 or sdc1, so
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* save to the kernel FP context & copy that to userland below.
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*/
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if (IS_ENABLED(CONFIG_EVA))
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lose_fpu(1);
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while (1) {
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lock_fpu_owner();
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if (is_fpu_owner()) {
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err = save_fp_context(sc);
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unlock_fpu_owner();
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} else {
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unlock_fpu_owner();
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err = copy_fp_to_sigcontext(sc);
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}
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if (likely(!err))
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break;
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/* touch the sigcontext and try again */
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err = __put_user(0, &fpregs[0]) |
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__put_user(0, &fpregs[31]) |
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__put_user(0, csr);
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if (err)
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return err; /* really bad sigcontext */
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}
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fp_done:
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ext_sz = err = save_extcontext(sc_to_extcontext(sc));
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if (err < 0)
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return err;
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used |= ext_sz ? USED_EXTCONTEXT : 0;
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return __put_user(used, used_math);
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}
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int protected_restore_fp_context(void __user *sc)
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{
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struct mips_abi *abi = current->thread.abi;
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uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
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uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
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uint32_t __user *used_math = sc + abi->off_sc_used_math;
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unsigned int used;
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int err, sig = 0, tmp __maybe_unused;
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err = __get_user(used, used_math);
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conditional_used_math(used & USED_FP);
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/*
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* The signal handler may have used FPU; give it up if the program
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* doesn't want it following sigreturn.
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*/
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if (err || !(used & USED_FP))
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lose_fpu(0);
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if (err)
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return err;
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if (!(used & USED_FP))
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goto fp_done;
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err = sig = fpcsr_pending(csr);
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if (err < 0)
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return err;
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/*
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* EVA does not have userland equivalents of ldc1 or sdc1, so we
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* disable the FPU here such that the code below simply copies to
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* the kernel FP context.
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*/
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if (IS_ENABLED(CONFIG_EVA))
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lose_fpu(0);
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while (1) {
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lock_fpu_owner();
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if (is_fpu_owner()) {
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err = restore_fp_context(sc);
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unlock_fpu_owner();
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} else {
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unlock_fpu_owner();
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err = copy_fp_from_sigcontext(sc);
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}
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if (likely(!err))
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break;
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/* touch the sigcontext and try again */
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err = __get_user(tmp, &fpregs[0]) |
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__get_user(tmp, &fpregs[31]) |
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__get_user(tmp, csr);
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if (err)
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break; /* really bad sigcontext */
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}
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fp_done:
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if (!err && (used & USED_EXTCONTEXT))
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err = restore_extcontext(sc_to_extcontext(sc));
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return err ?: sig;
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}
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int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
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{
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int err = 0;
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int i;
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err |= __put_user(regs->cp0_epc, &sc->sc_pc);
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err |= __put_user(0, &sc->sc_regs[0]);
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for (i = 1; i < 32; i++)
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err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
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#ifdef CONFIG_CPU_HAS_SMARTMIPS
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err |= __put_user(regs->acx, &sc->sc_acx);
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#endif
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err |= __put_user(regs->hi, &sc->sc_mdhi);
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err |= __put_user(regs->lo, &sc->sc_mdlo);
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if (cpu_has_dsp) {
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err |= __put_user(mfhi1(), &sc->sc_hi1);
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err |= __put_user(mflo1(), &sc->sc_lo1);
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err |= __put_user(mfhi2(), &sc->sc_hi2);
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err |= __put_user(mflo2(), &sc->sc_lo2);
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err |= __put_user(mfhi3(), &sc->sc_hi3);
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err |= __put_user(mflo3(), &sc->sc_lo3);
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err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
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}
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/*
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* Save FPU state to signal context. Signal handler
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* will "inherit" current FPU state.
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*/
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err |= protected_save_fp_context(sc);
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return err;
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}
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static size_t extcontext_max_size(void)
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{
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size_t sz = 0;
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/*
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* The assumption here is that between this point & the point at which
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* the extended context is saved the size of the context should only
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* ever be able to shrink (if the task is preempted), but never grow.
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* That is, what this function returns is an upper bound on the size of
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* the extended context for the current task at the current time.
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*/
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if (thread_msa_context_live())
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sz += sizeof(struct msa_extcontext);
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/* If any context is saved then we'll append the end marker */
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if (sz)
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sz += sizeof(((struct extcontext *)NULL)->magic);
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return sz;
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}
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int fpcsr_pending(unsigned int __user *fpcsr)
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{
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int err, sig = 0;
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unsigned int csr, enabled;
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err = __get_user(csr, fpcsr);
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enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
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/*
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* If the signal handler set some FPU exceptions, clear it and
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* send SIGFPE.
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*/
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if (csr & enabled) {
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csr &= ~enabled;
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err |= __put_user(csr, fpcsr);
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sig = SIGFPE;
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}
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return err ?: sig;
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}
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int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
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{
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unsigned long treg;
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int err = 0;
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int i;
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/* Always make any pending restarted system calls return -EINTR */
|
|
current->restart_block.fn = do_no_restart_syscall;
|
|
|
|
err |= __get_user(regs->cp0_epc, &sc->sc_pc);
|
|
|
|
#ifdef CONFIG_CPU_HAS_SMARTMIPS
|
|
err |= __get_user(regs->acx, &sc->sc_acx);
|
|
#endif
|
|
err |= __get_user(regs->hi, &sc->sc_mdhi);
|
|
err |= __get_user(regs->lo, &sc->sc_mdlo);
|
|
if (cpu_has_dsp) {
|
|
err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
|
|
err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
|
|
err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
|
|
err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
|
|
err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
|
|
err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
|
|
err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
|
|
}
|
|
|
|
for (i = 1; i < 32; i++)
|
|
err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
|
|
|
|
return err ?: protected_restore_fp_context(sc);
|
|
}
|
|
|
|
void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
|
|
size_t frame_size)
|
|
{
|
|
unsigned long sp;
|
|
|
|
/* Leave space for potential extended context */
|
|
frame_size += extcontext_max_size();
|
|
|
|
/* Default to using normal stack */
|
|
sp = regs->regs[29];
|
|
|
|
/*
|
|
* FPU emulator may have it's own trampoline active just
|
|
* above the user stack, 16-bytes before the next lowest
|
|
* 16 byte boundary. Try to avoid trashing it.
|
|
*/
|
|
sp -= 32;
|
|
|
|
sp = sigsp(sp, ksig);
|
|
|
|
return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
|
|
}
|
|
|
|
/*
|
|
* Atomically swap in the new signal mask, and wait for a signal.
|
|
*/
|
|
|
|
#ifdef CONFIG_TRAD_SIGNALS
|
|
SYSCALL_DEFINE1(sigsuspend, sigset_t __user *, uset)
|
|
{
|
|
return sys_rt_sigsuspend(uset, sizeof(sigset_t));
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_TRAD_SIGNALS
|
|
SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act,
|
|
struct sigaction __user *, oact)
|
|
{
|
|
struct k_sigaction new_ka, old_ka;
|
|
int ret;
|
|
int err = 0;
|
|
|
|
if (act) {
|
|
old_sigset_t mask;
|
|
|
|
if (!access_ok(act, sizeof(*act)))
|
|
return -EFAULT;
|
|
err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
|
|
err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
|
|
err |= __get_user(mask, &act->sa_mask.sig[0]);
|
|
if (err)
|
|
return -EFAULT;
|
|
|
|
siginitset(&new_ka.sa.sa_mask, mask);
|
|
}
|
|
|
|
ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
|
|
|
|
if (!ret && oact) {
|
|
if (!access_ok(oact, sizeof(*oact)))
|
|
return -EFAULT;
|
|
err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
|
|
err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
|
|
err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
|
|
err |= __put_user(0, &oact->sa_mask.sig[1]);
|
|
err |= __put_user(0, &oact->sa_mask.sig[2]);
|
|
err |= __put_user(0, &oact->sa_mask.sig[3]);
|
|
if (err)
|
|
return -EFAULT;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_TRAD_SIGNALS
|
|
asmlinkage void sys_sigreturn(void)
|
|
{
|
|
struct sigframe __user *frame;
|
|
struct pt_regs *regs;
|
|
sigset_t blocked;
|
|
int sig;
|
|
|
|
regs = current_pt_regs();
|
|
frame = (struct sigframe __user *)regs->regs[29];
|
|
if (!access_ok(frame, sizeof(*frame)))
|
|
goto badframe;
|
|
if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
|
|
goto badframe;
|
|
|
|
set_current_blocked(&blocked);
|
|
|
|
sig = restore_sigcontext(regs, &frame->sf_sc);
|
|
if (sig < 0)
|
|
goto badframe;
|
|
else if (sig)
|
|
force_sig(sig);
|
|
|
|
/*
|
|
* Don't let your children do this ...
|
|
*/
|
|
__asm__ __volatile__(
|
|
"move\t$29, %0\n\t"
|
|
"j\tsyscall_exit"
|
|
: /* no outputs */
|
|
: "r" (regs));
|
|
/* Unreached */
|
|
|
|
badframe:
|
|
force_sig(SIGSEGV);
|
|
}
|
|
#endif /* CONFIG_TRAD_SIGNALS */
|
|
|
|
asmlinkage void sys_rt_sigreturn(void)
|
|
{
|
|
struct rt_sigframe __user *frame;
|
|
struct pt_regs *regs;
|
|
sigset_t set;
|
|
int sig;
|
|
|
|
regs = current_pt_regs();
|
|
frame = (struct rt_sigframe __user *)regs->regs[29];
|
|
if (!access_ok(frame, sizeof(*frame)))
|
|
goto badframe;
|
|
if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
|
|
goto badframe;
|
|
|
|
set_current_blocked(&set);
|
|
|
|
sig = restore_sigcontext(regs, &frame->rs_uc.uc_mcontext);
|
|
if (sig < 0)
|
|
goto badframe;
|
|
else if (sig)
|
|
force_sig(sig);
|
|
|
|
if (restore_altstack(&frame->rs_uc.uc_stack))
|
|
goto badframe;
|
|
|
|
/*
|
|
* Don't let your children do this ...
|
|
*/
|
|
__asm__ __volatile__(
|
|
"move\t$29, %0\n\t"
|
|
"j\tsyscall_exit"
|
|
: /* no outputs */
|
|
: "r" (regs));
|
|
/* Unreached */
|
|
|
|
badframe:
|
|
force_sig(SIGSEGV);
|
|
}
|
|
|
|
#ifdef CONFIG_TRAD_SIGNALS
|
|
static int setup_frame(void *sig_return, struct ksignal *ksig,
|
|
struct pt_regs *regs, sigset_t *set)
|
|
{
|
|
struct sigframe __user *frame;
|
|
int err = 0;
|
|
|
|
frame = get_sigframe(ksig, regs, sizeof(*frame));
|
|
if (!access_ok(frame, sizeof (*frame)))
|
|
return -EFAULT;
|
|
|
|
err |= setup_sigcontext(regs, &frame->sf_sc);
|
|
err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
|
|
if (err)
|
|
return -EFAULT;
|
|
|
|
/*
|
|
* Arguments to signal handler:
|
|
*
|
|
* a0 = signal number
|
|
* a1 = 0 (should be cause)
|
|
* a2 = pointer to struct sigcontext
|
|
*
|
|
* $25 and c0_epc point to the signal handler, $29 points to the
|
|
* struct sigframe.
|
|
*/
|
|
regs->regs[ 4] = ksig->sig;
|
|
regs->regs[ 5] = 0;
|
|
regs->regs[ 6] = (unsigned long) &frame->sf_sc;
|
|
regs->regs[29] = (unsigned long) frame;
|
|
regs->regs[31] = (unsigned long) sig_return;
|
|
regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
|
|
|
|
DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
|
|
current->comm, current->pid,
|
|
frame, regs->cp0_epc, regs->regs[31]);
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
|
|
struct pt_regs *regs, sigset_t *set)
|
|
{
|
|
struct rt_sigframe __user *frame;
|
|
int err = 0;
|
|
|
|
frame = get_sigframe(ksig, regs, sizeof(*frame));
|
|
if (!access_ok(frame, sizeof (*frame)))
|
|
return -EFAULT;
|
|
|
|
/* Create siginfo. */
|
|
err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info);
|
|
|
|
/* Create the ucontext. */
|
|
err |= __put_user(0, &frame->rs_uc.uc_flags);
|
|
err |= __put_user(NULL, &frame->rs_uc.uc_link);
|
|
err |= __save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
|
|
err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
|
|
err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
|
|
|
|
if (err)
|
|
return -EFAULT;
|
|
|
|
/*
|
|
* Arguments to signal handler:
|
|
*
|
|
* a0 = signal number
|
|
* a1 = 0 (should be cause)
|
|
* a2 = pointer to ucontext
|
|
*
|
|
* $25 and c0_epc point to the signal handler, $29 points to
|
|
* the struct rt_sigframe.
|
|
*/
|
|
regs->regs[ 4] = ksig->sig;
|
|
regs->regs[ 5] = (unsigned long) &frame->rs_info;
|
|
regs->regs[ 6] = (unsigned long) &frame->rs_uc;
|
|
regs->regs[29] = (unsigned long) frame;
|
|
regs->regs[31] = (unsigned long) sig_return;
|
|
regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
|
|
|
|
DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
|
|
current->comm, current->pid,
|
|
frame, regs->cp0_epc, regs->regs[31]);
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct mips_abi mips_abi = {
|
|
#ifdef CONFIG_TRAD_SIGNALS
|
|
.setup_frame = setup_frame,
|
|
#endif
|
|
.setup_rt_frame = setup_rt_frame,
|
|
.restart = __NR_restart_syscall,
|
|
|
|
.off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
|
|
.off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
|
|
.off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
|
|
|
|
.vdso = &vdso_image,
|
|
};
|
|
|
|
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
|
|
{
|
|
sigset_t *oldset = sigmask_to_save();
|
|
int ret;
|
|
struct mips_abi *abi = current->thread.abi;
|
|
void *vdso = current->mm->context.vdso;
|
|
|
|
/*
|
|
* If we were emulating a delay slot instruction, exit that frame such
|
|
* that addresses in the sigframe are as expected for userland and we
|
|
* don't have a problem if we reuse the thread's frame for an
|
|
* instruction within the signal handler.
|
|
*/
|
|
dsemul_thread_rollback(regs);
|
|
|
|
if (regs->regs[0]) {
|
|
switch(regs->regs[2]) {
|
|
case ERESTART_RESTARTBLOCK:
|
|
case ERESTARTNOHAND:
|
|
regs->regs[2] = EINTR;
|
|
break;
|
|
case ERESTARTSYS:
|
|
if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
|
|
regs->regs[2] = EINTR;
|
|
break;
|
|
}
|
|
/* fallthrough */
|
|
case ERESTARTNOINTR:
|
|
regs->regs[7] = regs->regs[26];
|
|
regs->regs[2] = regs->regs[0];
|
|
regs->cp0_epc -= 4;
|
|
}
|
|
|
|
regs->regs[0] = 0; /* Don't deal with this again. */
|
|
}
|
|
|
|
rseq_signal_deliver(ksig, regs);
|
|
|
|
if (sig_uses_siginfo(&ksig->ka, abi))
|
|
ret = abi->setup_rt_frame(vdso + abi->vdso->off_rt_sigreturn,
|
|
ksig, regs, oldset);
|
|
else
|
|
ret = abi->setup_frame(vdso + abi->vdso->off_sigreturn,
|
|
ksig, regs, oldset);
|
|
|
|
signal_setup_done(ret, ksig, 0);
|
|
}
|
|
|
|
static void do_signal(struct pt_regs *regs)
|
|
{
|
|
struct ksignal ksig;
|
|
|
|
if (get_signal(&ksig)) {
|
|
/* Whee! Actually deliver the signal. */
|
|
handle_signal(&ksig, regs);
|
|
return;
|
|
}
|
|
|
|
if (regs->regs[0]) {
|
|
switch (regs->regs[2]) {
|
|
case ERESTARTNOHAND:
|
|
case ERESTARTSYS:
|
|
case ERESTARTNOINTR:
|
|
regs->regs[2] = regs->regs[0];
|
|
regs->regs[7] = regs->regs[26];
|
|
regs->cp0_epc -= 4;
|
|
break;
|
|
|
|
case ERESTART_RESTARTBLOCK:
|
|
regs->regs[2] = current->thread.abi->restart;
|
|
regs->regs[7] = regs->regs[26];
|
|
regs->cp0_epc -= 4;
|
|
break;
|
|
}
|
|
regs->regs[0] = 0; /* Don't deal with this again. */
|
|
}
|
|
|
|
/*
|
|
* If there's no signal to deliver, we just put the saved sigmask
|
|
* back
|
|
*/
|
|
restore_saved_sigmask();
|
|
}
|
|
|
|
/*
|
|
* notification of userspace execution resumption
|
|
* - triggered by the TIF_WORK_MASK flags
|
|
*/
|
|
asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
|
|
__u32 thread_info_flags)
|
|
{
|
|
local_irq_enable();
|
|
|
|
user_exit();
|
|
|
|
if (thread_info_flags & _TIF_UPROBE)
|
|
uprobe_notify_resume(regs);
|
|
|
|
/* deal with pending signal delivery */
|
|
if (thread_info_flags & _TIF_SIGPENDING)
|
|
do_signal(regs);
|
|
|
|
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
|
|
clear_thread_flag(TIF_NOTIFY_RESUME);
|
|
tracehook_notify_resume(regs);
|
|
rseq_handle_notify_resume(NULL, regs);
|
|
}
|
|
|
|
user_enter();
|
|
}
|
|
|
|
#if defined(CONFIG_SMP) && defined(CONFIG_MIPS_FP_SUPPORT)
|
|
static int smp_save_fp_context(void __user *sc)
|
|
{
|
|
return raw_cpu_has_fpu
|
|
? save_hw_fp_context(sc)
|
|
: copy_fp_to_sigcontext(sc);
|
|
}
|
|
|
|
static int smp_restore_fp_context(void __user *sc)
|
|
{
|
|
return raw_cpu_has_fpu
|
|
? restore_hw_fp_context(sc)
|
|
: copy_fp_from_sigcontext(sc);
|
|
}
|
|
#endif
|
|
|
|
static int signal_setup(void)
|
|
{
|
|
/*
|
|
* The offset from sigcontext to extended context should be the same
|
|
* regardless of the type of signal, such that userland can always know
|
|
* where to look if it wishes to find the extended context structures.
|
|
*/
|
|
BUILD_BUG_ON((offsetof(struct sigframe, sf_extcontext) -
|
|
offsetof(struct sigframe, sf_sc)) !=
|
|
(offsetof(struct rt_sigframe, rs_uc.uc_extcontext) -
|
|
offsetof(struct rt_sigframe, rs_uc.uc_mcontext)));
|
|
|
|
#if defined(CONFIG_SMP) && defined(CONFIG_MIPS_FP_SUPPORT)
|
|
/* For now just do the cpu_has_fpu check when the functions are invoked */
|
|
save_fp_context = smp_save_fp_context;
|
|
restore_fp_context = smp_restore_fp_context;
|
|
#else
|
|
if (cpu_has_fpu) {
|
|
save_fp_context = save_hw_fp_context;
|
|
restore_fp_context = restore_hw_fp_context;
|
|
} else {
|
|
save_fp_context = copy_fp_to_sigcontext;
|
|
restore_fp_context = copy_fp_from_sigcontext;
|
|
}
|
|
#endif /* CONFIG_SMP */
|
|
|
|
return 0;
|
|
}
|
|
|
|
arch_initcall(signal_setup);
|