From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- arch/mips/kernel/signal.c | 968 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 968 insertions(+) create mode 100644 arch/mips/kernel/signal.c (limited to 'arch/mips/kernel/signal.c') diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c new file mode 100644 index 000000000..479999b7f --- /dev/null +++ b/arch/mips/kernel/signal.c @@ -0,0 +1,968 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright (C) 1994 - 2000 Ralf Baechle + * Copyright (C) 1999, 2000 Silicon Graphics, Inc. + * Copyright (C) 2014, Imagination Technologies Ltd. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "signal-common.h" + +static int (*save_fp_context)(void __user *sc); +static int (*restore_fp_context)(void __user *sc); + +struct sigframe { + u32 sf_ass[4]; /* argument save space for o32 */ + u32 sf_pad[2]; /* Was: signal trampoline */ + + /* Matches struct ucontext from its uc_mcontext field onwards */ + struct sigcontext sf_sc; + sigset_t sf_mask; + unsigned long long sf_extcontext[]; +}; + +struct rt_sigframe { + u32 rs_ass[4]; /* argument save space for o32 */ + u32 rs_pad[2]; /* Was: signal trampoline */ + struct siginfo rs_info; + struct ucontext rs_uc; +}; + +#ifdef CONFIG_MIPS_FP_SUPPORT + +/* + * Thread saved context copy to/from a signal context presumed to be on the + * user stack, and therefore accessed with appropriate macros from uaccess.h. + */ +static int copy_fp_to_sigcontext(void __user *sc) +{ + struct mips_abi *abi = current->thread.abi; + uint64_t __user *fpregs = sc + abi->off_sc_fpregs; + uint32_t __user *csr = sc + abi->off_sc_fpc_csr; + int i; + int err = 0; + int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1; + + for (i = 0; i < NUM_FPU_REGS; i += inc) { + err |= + __put_user(get_fpr64(¤t->thread.fpu.fpr[i], 0), + &fpregs[i]); + } + err |= __put_user(current->thread.fpu.fcr31, csr); + + return err; +} + +static int copy_fp_from_sigcontext(void __user *sc) +{ + struct mips_abi *abi = current->thread.abi; + uint64_t __user *fpregs = sc + abi->off_sc_fpregs; + uint32_t __user *csr = sc + abi->off_sc_fpc_csr; + int i; + int err = 0; + int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1; + u64 fpr_val; + + for (i = 0; i < NUM_FPU_REGS; i += inc) { + err |= __get_user(fpr_val, &fpregs[i]); + set_fpr64(¤t->thread.fpu.fpr[i], 0, fpr_val); + } + err |= __get_user(current->thread.fpu.fcr31, csr); + + return err; +} + +#else /* !CONFIG_MIPS_FP_SUPPORT */ + +static int copy_fp_to_sigcontext(void __user *sc) +{ + return 0; +} + +static int copy_fp_from_sigcontext(void __user *sc) +{ + return 0; +} + +#endif /* !CONFIG_MIPS_FP_SUPPORT */ + +/* + * Wrappers for the assembly _{save,restore}_fp_context functions. + */ +static int save_hw_fp_context(void __user *sc) +{ + struct mips_abi *abi = current->thread.abi; + uint64_t __user *fpregs = sc + abi->off_sc_fpregs; + uint32_t __user *csr = sc + abi->off_sc_fpc_csr; + + return _save_fp_context(fpregs, csr); +} + +static int restore_hw_fp_context(void __user *sc) +{ + struct mips_abi *abi = current->thread.abi; + uint64_t __user *fpregs = sc + abi->off_sc_fpregs; + uint32_t __user *csr = sc + abi->off_sc_fpc_csr; + + return _restore_fp_context(fpregs, csr); +} + +/* + * Extended context handling. + */ + +static inline void __user *sc_to_extcontext(void __user *sc) +{ + struct ucontext __user *uc; + + /* + * We can just pretend the sigcontext is always embedded in a struct + * ucontext here, because the offset from sigcontext to extended + * context is the same in the struct sigframe case. + */ + uc = container_of(sc, struct ucontext, uc_mcontext); + return &uc->uc_extcontext; +} + +#ifdef CONFIG_CPU_HAS_MSA + +static int save_msa_extcontext(void __user *buf) +{ + struct msa_extcontext __user *msa = buf; + uint64_t val; + int i, err; + + if (!thread_msa_context_live()) + return 0; + + /* + * Ensure that we can't lose the live MSA context between checking + * for it & writing it to memory. + */ + preempt_disable(); + + if (is_msa_enabled()) { + /* + * There are no EVA versions of the vector register load/store + * instructions, so MSA context has to be saved to kernel memory + * and then copied to user memory. The save to kernel memory + * should already have been done when handling scalar FP + * context. + */ + BUG_ON(IS_ENABLED(CONFIG_EVA)); + + err = __put_user(read_msa_csr(), &msa->csr); + err |= _save_msa_all_upper(&msa->wr); + + preempt_enable(); + } else { + preempt_enable(); + + err = __put_user(current->thread.fpu.msacsr, &msa->csr); + + for (i = 0; i < NUM_FPU_REGS; i++) { + val = get_fpr64(¤t->thread.fpu.fpr[i], 1); + err |= __put_user(val, &msa->wr[i]); + } + } + + err |= __put_user(MSA_EXTCONTEXT_MAGIC, &msa->ext.magic); + err |= __put_user(sizeof(*msa), &msa->ext.size); + + return err ? -EFAULT : sizeof(*msa); +} + +static int restore_msa_extcontext(void __user *buf, unsigned int size) +{ + struct msa_extcontext __user *msa = buf; + unsigned long long val; + unsigned int csr; + int i, err; + + if (size != sizeof(*msa)) + return -EINVAL; + + err = get_user(csr, &msa->csr); + if (err) + return err; + + preempt_disable(); + + if (is_msa_enabled()) { + /* + * There are no EVA versions of the vector register load/store + * instructions, so MSA context has to be copied to kernel + * memory and later loaded to registers. The same is true of + * scalar FP context, so FPU & MSA should have already been + * disabled whilst handling scalar FP context. + */ + BUG_ON(IS_ENABLED(CONFIG_EVA)); + + write_msa_csr(csr); + err |= _restore_msa_all_upper(&msa->wr); + preempt_enable(); + } else { + preempt_enable(); + + current->thread.fpu.msacsr = csr; + + for (i = 0; i < NUM_FPU_REGS; i++) { + err |= __get_user(val, &msa->wr[i]); + set_fpr64(¤t->thread.fpu.fpr[i], 1, val); + } + } + + return err; +} + +#else /* !CONFIG_CPU_HAS_MSA */ + +static int save_msa_extcontext(void __user *buf) +{ + return 0; +} + +static int restore_msa_extcontext(void __user *buf, unsigned int size) +{ + return SIGSYS; +} + +#endif /* !CONFIG_CPU_HAS_MSA */ + +static int save_extcontext(void __user *buf) +{ + int sz; + + sz = save_msa_extcontext(buf); + if (sz < 0) + return sz; + buf += sz; + + /* If no context was saved then trivially return */ + if (!sz) + return 0; + + /* Write the end marker */ + if (__put_user(END_EXTCONTEXT_MAGIC, (u32 *)buf)) + return -EFAULT; + + sz += sizeof(((struct extcontext *)NULL)->magic); + return sz; +} + +static int restore_extcontext(void __user *buf) +{ + struct extcontext ext; + int err; + + while (1) { + err = __get_user(ext.magic, (unsigned int *)buf); + if (err) + return err; + + if (ext.magic == END_EXTCONTEXT_MAGIC) + return 0; + + err = __get_user(ext.size, (unsigned int *)(buf + + offsetof(struct extcontext, size))); + if (err) + return err; + + switch (ext.magic) { + case MSA_EXTCONTEXT_MAGIC: + err = restore_msa_extcontext(buf, ext.size); + break; + + default: + err = -EINVAL; + break; + } + + if (err) + return err; + + buf += ext.size; + } +} + +/* + * Helper routines + */ +int protected_save_fp_context(void __user *sc) +{ + struct mips_abi *abi = current->thread.abi; + uint64_t __user *fpregs = sc + abi->off_sc_fpregs; + uint32_t __user *csr = sc + abi->off_sc_fpc_csr; + uint32_t __user *used_math = sc + abi->off_sc_used_math; + unsigned int used, ext_sz; + int err; + + used = used_math() ? USED_FP : 0; + if (!used) + goto fp_done; + + if (!test_thread_flag(TIF_32BIT_FPREGS)) + used |= USED_FR1; + if (test_thread_flag(TIF_HYBRID_FPREGS)) + used |= USED_HYBRID_FPRS; + + /* + * EVA does not have userland equivalents of ldc1 or sdc1, so + * save to the kernel FP context & copy that to userland below. + */ + if (IS_ENABLED(CONFIG_EVA)) + lose_fpu(1); + + while (1) { + lock_fpu_owner(); + if (is_fpu_owner()) { + err = save_fp_context(sc); + unlock_fpu_owner(); + } else { + unlock_fpu_owner(); + err = copy_fp_to_sigcontext(sc); + } + if (likely(!err)) + break; + /* touch the sigcontext and try again */ + err = __put_user(0, &fpregs[0]) | + __put_user(0, &fpregs[31]) | + __put_user(0, csr); + if (err) + return err; /* really bad sigcontext */ + } + +fp_done: + ext_sz = err = save_extcontext(sc_to_extcontext(sc)); + if (err < 0) + return err; + used |= ext_sz ? USED_EXTCONTEXT : 0; + + return __put_user(used, used_math); +} + +int protected_restore_fp_context(void __user *sc) +{ + struct mips_abi *abi = current->thread.abi; + uint64_t __user *fpregs = sc + abi->off_sc_fpregs; + uint32_t __user *csr = sc + abi->off_sc_fpc_csr; + uint32_t __user *used_math = sc + abi->off_sc_used_math; + unsigned int used; + int err, sig = 0, tmp __maybe_unused; + + err = __get_user(used, used_math); + conditional_used_math(used & USED_FP); + + /* + * The signal handler may have used FPU; give it up if the program + * doesn't want it following sigreturn. + */ + if (err || !(used & USED_FP)) + lose_fpu(0); + if (err) + return err; + if (!(used & USED_FP)) + goto fp_done; + + err = sig = fpcsr_pending(csr); + if (err < 0) + return err; + + /* + * EVA does not have userland equivalents of ldc1 or sdc1, so we + * disable the FPU here such that the code below simply copies to + * the kernel FP context. + */ + if (IS_ENABLED(CONFIG_EVA)) + lose_fpu(0); + + while (1) { + lock_fpu_owner(); + if (is_fpu_owner()) { + err = restore_fp_context(sc); + unlock_fpu_owner(); + } else { + unlock_fpu_owner(); + err = copy_fp_from_sigcontext(sc); + } + if (likely(!err)) + break; + /* touch the sigcontext and try again */ + err = __get_user(tmp, &fpregs[0]) | + __get_user(tmp, &fpregs[31]) | + __get_user(tmp, csr); + if (err) + break; /* really bad sigcontext */ + } + +fp_done: + if (!err && (used & USED_EXTCONTEXT)) + err = restore_extcontext(sc_to_extcontext(sc)); + + return err ?: sig; +} + +int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) +{ + int err = 0; + int i; + + err |= __put_user(regs->cp0_epc, &sc->sc_pc); + + err |= __put_user(0, &sc->sc_regs[0]); + for (i = 1; i < 32; i++) + err |= __put_user(regs->regs[i], &sc->sc_regs[i]); + +#ifdef CONFIG_CPU_HAS_SMARTMIPS + err |= __put_user(regs->acx, &sc->sc_acx); +#endif + err |= __put_user(regs->hi, &sc->sc_mdhi); + err |= __put_user(regs->lo, &sc->sc_mdlo); + if (cpu_has_dsp) { + err |= __put_user(mfhi1(), &sc->sc_hi1); + err |= __put_user(mflo1(), &sc->sc_lo1); + err |= __put_user(mfhi2(), &sc->sc_hi2); + err |= __put_user(mflo2(), &sc->sc_lo2); + err |= __put_user(mfhi3(), &sc->sc_hi3); + err |= __put_user(mflo3(), &sc->sc_lo3); + err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp); + } + + + /* + * Save FPU state to signal context. Signal handler + * will "inherit" current FPU state. + */ + err |= protected_save_fp_context(sc); + + return err; +} + +static size_t extcontext_max_size(void) +{ + size_t sz = 0; + + /* + * The assumption here is that between this point & the point at which + * the extended context is saved the size of the context should only + * ever be able to shrink (if the task is preempted), but never grow. + * That is, what this function returns is an upper bound on the size of + * the extended context for the current task at the current time. + */ + + if (thread_msa_context_live()) + sz += sizeof(struct msa_extcontext); + + /* If any context is saved then we'll append the end marker */ + if (sz) + sz += sizeof(((struct extcontext *)NULL)->magic); + + return sz; +} + +int fpcsr_pending(unsigned int __user *fpcsr) +{ + int err, sig = 0; + unsigned int csr, enabled; + + err = __get_user(csr, fpcsr); + enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5); + /* + * If the signal handler set some FPU exceptions, clear it and + * send SIGFPE. + */ + if (csr & enabled) { + csr &= ~enabled; + err |= __put_user(csr, fpcsr); + sig = SIGFPE; + } + return err ?: sig; +} + +int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) +{ + unsigned long treg; + int err = 0; + int i; + + /* 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); +} + +#ifdef CONFIG_WAR_ICACHE_REFILLS +#define SIGMASK ~(cpu_icache_line_size()-1) +#else +#define SIGMASK ALMASK +#endif + +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]; + + /* + * If we are on the alternate signal stack and would overflow it, don't. + * Return an always-bogus address instead so we will die with SIGSEGV. + */ + if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size))) + return (void __user __force *)(-1UL); + + /* + * 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) & SIGMASK); +} + +/* + * 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; + + frame = get_sigframe(ksig, regs, sizeof(*frame)); + if (!access_ok(frame, sizeof (*frame))) + return -EFAULT; + + /* Create siginfo. */ + if (copy_siginfo_to_user(&frame->rs_info, &ksig->info)) + return -EFAULT; + + /* Create the ucontext. */ + if (__put_user(0, &frame->rs_uc.uc_flags)) + return -EFAULT; + if (__put_user(NULL, &frame->rs_uc.uc_link)) + return -EFAULT; + if (__save_altstack(&frame->rs_uc.uc_stack, regs->regs[29])) + return -EFAULT; + if (setup_sigcontext(regs, &frame->rs_uc.uc_mcontext)) + return -EFAULT; + if (__copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set))) + 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 | _TIF_NOTIFY_SIGNAL)) + do_signal(regs); + + if (thread_info_flags & _TIF_NOTIFY_RESUME) + resume_user_mode_work(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); -- cgit v1.2.3