--- zzzz-none-000/linux-3.10.107/arch/mips/kernel/signal.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/arch/mips/kernel/signal.c 2021-02-04 17:41:59.000000000 +0000 @@ -6,8 +6,10 @@ * 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 @@ -19,6 +21,7 @@ #include #include #include +#include #include #include #include @@ -33,26 +36,23 @@ #include #include #include -#include #include #include +#include #include "signal-common.h" -static int (*save_fp_context)(struct sigcontext __user *sc); -static int (*restore_fp_context)(struct sigcontext __user *sc); - -extern asmlinkage int _save_fp_context(struct sigcontext __user *sc); -extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc); - -extern asmlinkage int fpu_emulator_save_context(struct sigcontext __user *sc); -extern asmlinkage int fpu_emulator_restore_context(struct sigcontext __user *sc); +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[0]; }; struct rt_sigframe { @@ -63,53 +63,354 @@ }; /* + * 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; +} + +/* + * 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; +} + +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(config_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 (!config_enabled(CONFIG_CPU_HAS_MSA)) + return SIGSYS; + + 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(config_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; +} + +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 */ -static int protected_save_fp_context(struct sigcontext __user *sc) +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 (config_enabled(CONFIG_EVA)) + lose_fpu(1); + while (1) { lock_fpu_owner(); - own_fpu_inatomic(1); - err = save_fp_context(sc); /* this might fail */ - unlock_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, &sc->sc_fpregs[0]) | - __put_user(0, &sc->sc_fpregs[31]) | - __put_user(0, &sc->sc_fpc_csr); + err = __put_user(0, &fpregs[0]) | + __put_user(0, &fpregs[31]) | + __put_user(0, csr); if (err) - break; /* really bad sigcontext */ + return err; /* really bad sigcontext */ } - return err; + +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); } -static int protected_restore_fp_context(struct sigcontext __user *sc) +int protected_restore_fp_context(void __user *sc) { - int err, tmp __maybe_unused; + 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 (config_enabled(CONFIG_EVA)) + lose_fpu(0); + while (1) { lock_fpu_owner(); - own_fpu_inatomic(0); - err = restore_fp_context(sc); /* this might fail */ - unlock_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, &sc->sc_fpregs[0]) | - __get_user(tmp, &sc->sc_fpregs[31]) | - __get_user(tmp, &sc->sc_fpc_csr); + err = __get_user(tmp, &fpregs[0]) | + __get_user(tmp, &fpregs[31]) | + __get_user(tmp, csr); if (err) break; /* really bad sigcontext */ } - return err; + +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; - unsigned int used_math; err |= __put_user(regs->cp0_epc, &sc->sc_pc); @@ -132,19 +433,38 @@ err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp); } - used_math = !!used_math(); - err |= __put_user(used_math, &sc->sc_used_math); - if (used_math) { - /* - * Save FPU state to signal context. Signal handler - * will "inherit" current FPU state. - */ - err |= protected_save_fp_context(sc); - } + /* + * 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; @@ -164,27 +484,14 @@ return err ?: sig; } -static int -check_and_restore_fp_context(struct sigcontext __user *sc) -{ - int err, sig; - - err = sig = fpcsr_pending(&sc->sc_fpc_csr); - if (err > 0) - err = 0; - err |= protected_restore_fp_context(sc); - return err ?: sig; -} - int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) { - unsigned int used_math; unsigned long treg; int err = 0; int i; /* Always make any pending restarted system calls return -EINTR */ - current_thread_info()->restart_block.fn = do_no_restart_syscall; + current->restart_block.fn = do_no_restart_syscall; err |= __get_user(regs->cp0_epc, &sc->sc_pc); @@ -206,26 +513,17 @@ for (i = 1; i < 32; i++) err |= __get_user(regs->regs[i], &sc->sc_regs[i]); - err |= __get_user(used_math, &sc->sc_used_math); - conditional_used_math(used_math); - - if (used_math) { - /* restore fpu context if we have used it before */ - if (!err) - err = check_and_restore_fp_context(sc); - } else { - /* signal handler may have used FPU. Give it up. */ - lose_fpu(0); - } - - return err; + return err ?: protected_restore_fp_context(sc); } -void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, +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]; @@ -236,9 +534,7 @@ */ sp -= 32; - /* This is the X/Open sanctioned signal stack switching. */ - if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags (sp) == 0)) - sp = current->sas_ss_sp + current->sas_ss_size; + sp = sigsp(sp, ksig); return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK)); } @@ -369,20 +665,20 @@ } #ifdef CONFIG_TRAD_SIGNALS -static int setup_frame(void *sig_return, struct k_sigaction *ka, - struct pt_regs *regs, int signr, sigset_t *set) +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(ka, regs, sizeof(*frame)); + frame = get_sigframe(ksig, regs, sizeof(*frame)); if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) - goto give_sigsegv; + return -EFAULT; err |= setup_sigcontext(regs, &frame->sf_sc); err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set)); if (err) - goto give_sigsegv; + return -EFAULT; /* * Arguments to signal handler: @@ -394,37 +690,32 @@ * $25 and c0_epc point to the signal handler, $29 points to the * struct sigframe. */ - regs->regs[ 4] = signr; + 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) ka->sa.sa_handler; + 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; - -give_sigsegv: - force_sigsegv(signr, current); - return -EFAULT; } #endif -static int setup_rt_frame(void *sig_return, struct k_sigaction *ka, - struct pt_regs *regs, int signr, sigset_t *set, - siginfo_t *info) +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(ka, regs, sizeof(*frame)); + frame = get_sigframe(ksig, regs, sizeof(*frame)); if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) - goto give_sigsegv; + return -EFAULT; /* Create siginfo. */ - err |= copy_siginfo_to_user(&frame->rs_info, info); + err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info); /* Create the ucontext. */ err |= __put_user(0, &frame->rs_uc.uc_flags); @@ -434,7 +725,7 @@ err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set)); if (err) - goto give_sigsegv; + return -EFAULT; /* * Arguments to signal handler: @@ -446,50 +737,40 @@ * $25 and c0_epc point to the signal handler, $29 points to * the struct rt_sigframe. */ - regs->regs[ 4] = signr; + 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) ka->sa.sa_handler; + 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; - -give_sigsegv: - force_sigsegv(signr, current); - return -EFAULT; } struct mips_abi mips_abi = { #ifdef CONFIG_TRAD_SIGNALS .setup_frame = setup_frame, - .signal_return_offset = offsetof(struct mips_vdso, signal_trampoline), #endif .setup_rt_frame = setup_rt_frame, - .rt_signal_return_offset = - offsetof(struct mips_vdso, rt_signal_trampoline), - .restart = __NR_restart_syscall + .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(unsigned long sig, siginfo_t *info, - struct k_sigaction *ka, struct pt_regs *regs) +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; -#ifdef CONFIG_CPU_MICROMIPS - void *vdso; - unsigned int tmp = (unsigned int)current->mm->context.vdso; - - set_isa16_mode(tmp); - vdso = (void *)tmp; -#else void *vdso = current->mm->context.vdso; -#endif if (regs->regs[0]) { switch(regs->regs[2]) { @@ -498,7 +779,7 @@ regs->regs[2] = EINTR; break; case ERESTARTSYS: - if (!(ka->sa.sa_flags & SA_RESTART)) { + if (!(ksig->ka.sa.sa_flags & SA_RESTART)) { regs->regs[2] = EINTR; break; } @@ -512,29 +793,23 @@ regs->regs[0] = 0; /* Don't deal with this again. */ } - if (sig_uses_siginfo(ka)) - ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset, - ka, regs, sig, oldset, info); + if (sig_uses_siginfo(&ksig->ka)) + ret = abi->setup_rt_frame(vdso + abi->vdso->off_rt_sigreturn, + ksig, regs, oldset); else - ret = abi->setup_frame(vdso + abi->signal_return_offset, - ka, regs, sig, oldset); - - if (ret) - return; + ret = abi->setup_frame(vdso + abi->vdso->off_sigreturn, + ksig, regs, oldset); - signal_delivered(sig, info, ka, regs, 0); + signal_setup_done(ret, ksig, 0); } static void do_signal(struct pt_regs *regs) { - struct k_sigaction ka; - siginfo_t info; - int signr; + struct ksignal ksig; - signr = get_signal_to_deliver(&info, &ka, regs, NULL); - if (signr > 0) { + if (get_signal(&ksig)) { /* Whee! Actually deliver the signal. */ - handle_signal(signr, &info, &ka, regs); + handle_signal(&ksig, regs); return; } @@ -573,6 +848,11 @@ { 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); @@ -581,39 +861,51 @@ clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); } + + user_enter(); } #ifdef CONFIG_SMP -static int smp_save_fp_context(struct sigcontext __user *sc) +static int smp_save_fp_context(void __user *sc) { return raw_cpu_has_fpu - ? _save_fp_context(sc) - : fpu_emulator_save_context(sc); + ? save_hw_fp_context(sc) + : copy_fp_to_sigcontext(sc); } -static int smp_restore_fp_context(struct sigcontext __user *sc) +static int smp_restore_fp_context(void __user *sc) { return raw_cpu_has_fpu - ? _restore_fp_context(sc) - : fpu_emulator_restore_context(sc); + ? 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))); + #ifdef CONFIG_SMP /* 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_fp_context; - restore_fp_context = _restore_fp_context; + save_fp_context = save_hw_fp_context; + restore_fp_context = restore_hw_fp_context; } else { - save_fp_context = fpu_emulator_save_context; - restore_fp_context = fpu_emulator_restore_context; + save_fp_context = copy_fp_to_sigcontext; + restore_fp_context = copy_fp_from_sigcontext; } -#endif +#endif /* CONFIG_SMP */ return 0; }