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/sparc/kernel/signal_32.c | 565 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 565 insertions(+) create mode 100644 arch/sparc/kernel/signal_32.c (limited to 'arch/sparc/kernel/signal_32.c') diff --git a/arch/sparc/kernel/signal_32.c b/arch/sparc/kernel/signal_32.c new file mode 100644 index 000000000..89b93c713 --- /dev/null +++ b/arch/sparc/kernel/signal_32.c @@ -0,0 +1,565 @@ +// SPDX-License-Identifier: GPL-2.0 +/* linux/arch/sparc/kernel/signal.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) + * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx) + * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be) + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include /* do_coredum */ +#include +#include + +#include +#include +#include /* flush_sig_insns */ +#include + +#include "sigutil.h" +#include "kernel.h" + +extern void fpsave(unsigned long *fpregs, unsigned long *fsr, + void *fpqueue, unsigned long *fpqdepth); +extern void fpload(unsigned long *fpregs, unsigned long *fsr); + +struct signal_frame { + struct sparc_stackf ss; + __siginfo32_t info; + __siginfo_fpu_t __user *fpu_save; + unsigned long insns[2] __attribute__ ((aligned (8))); + unsigned int extramask[_NSIG_WORDS - 1]; + unsigned int extra_size; /* Should be 0 */ + __siginfo_rwin_t __user *rwin_save; +} __attribute__((aligned(8))); + +struct rt_signal_frame { + struct sparc_stackf ss; + siginfo_t info; + struct pt_regs regs; + sigset_t mask; + __siginfo_fpu_t __user *fpu_save; + unsigned int insns[2]; + stack_t stack; + unsigned int extra_size; /* Should be 0 */ + __siginfo_rwin_t __user *rwin_save; +} __attribute__((aligned(8))); + +/* Align macros */ +#define SF_ALIGNEDSZ (((sizeof(struct signal_frame) + 7) & (~7))) +#define RT_ALIGNEDSZ (((sizeof(struct rt_signal_frame) + 7) & (~7))) + +/* Checks if the fp is valid. We always build signal frames which are + * 16-byte aligned, therefore we can always enforce that the restore + * frame has that property as well. + */ +static inline bool invalid_frame_pointer(void __user *fp, int fplen) +{ + if ((((unsigned long) fp) & 15) || !access_ok(fp, fplen)) + return true; + + return false; +} + +asmlinkage void do_sigreturn(struct pt_regs *regs) +{ + unsigned long up_psr, pc, npc, ufp; + struct signal_frame __user *sf; + sigset_t set; + __siginfo_fpu_t __user *fpu_save; + __siginfo_rwin_t __user *rwin_save; + int err; + + /* Always make any pending restarted system calls return -EINTR */ + current->restart_block.fn = do_no_restart_syscall; + + synchronize_user_stack(); + + sf = (struct signal_frame __user *) regs->u_regs[UREG_FP]; + + /* 1. Make sure we are not getting garbage from the user */ + if (invalid_frame_pointer(sf, sizeof(*sf))) + goto segv_and_exit; + + if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP])) + goto segv_and_exit; + + if (ufp & 0x7) + goto segv_and_exit; + + err = __get_user(pc, &sf->info.si_regs.pc); + err |= __get_user(npc, &sf->info.si_regs.npc); + + if ((pc | npc) & 3) + goto segv_and_exit; + + /* 2. Restore the state */ + up_psr = regs->psr; + err |= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs)); + + /* User can only change condition codes and FPU enabling in %psr. */ + regs->psr = (up_psr & ~(PSR_ICC | PSR_EF)) + | (regs->psr & (PSR_ICC | PSR_EF)); + + /* Prevent syscall restart. */ + pt_regs_clear_syscall(regs); + + err |= __get_user(fpu_save, &sf->fpu_save); + if (fpu_save) + err |= restore_fpu_state(regs, fpu_save); + err |= __get_user(rwin_save, &sf->rwin_save); + if (rwin_save) + err |= restore_rwin_state(rwin_save); + + /* This is pretty much atomic, no amount locking would prevent + * the races which exist anyways. + */ + err |= __get_user(set.sig[0], &sf->info.si_mask); + err |= __copy_from_user(&set.sig[1], &sf->extramask, + (_NSIG_WORDS-1) * sizeof(unsigned int)); + + if (err) + goto segv_and_exit; + + set_current_blocked(&set); + return; + +segv_and_exit: + force_sig(SIGSEGV); +} + +asmlinkage void do_rt_sigreturn(struct pt_regs *regs) +{ + struct rt_signal_frame __user *sf; + unsigned int psr, pc, npc, ufp; + __siginfo_fpu_t __user *fpu_save; + __siginfo_rwin_t __user *rwin_save; + sigset_t set; + int err; + + synchronize_user_stack(); + sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP]; + if (invalid_frame_pointer(sf, sizeof(*sf))) + goto segv; + + if (get_user(ufp, &sf->regs.u_regs[UREG_FP])) + goto segv; + + if (ufp & 0x7) + goto segv; + + err = __get_user(pc, &sf->regs.pc); + err |= __get_user(npc, &sf->regs.npc); + err |= ((pc | npc) & 0x03); + + err |= __get_user(regs->y, &sf->regs.y); + err |= __get_user(psr, &sf->regs.psr); + + err |= __copy_from_user(®s->u_regs[UREG_G1], + &sf->regs.u_regs[UREG_G1], 15 * sizeof(u32)); + + regs->psr = (regs->psr & ~PSR_ICC) | (psr & PSR_ICC); + + /* Prevent syscall restart. */ + pt_regs_clear_syscall(regs); + + err |= __get_user(fpu_save, &sf->fpu_save); + if (!err && fpu_save) + err |= restore_fpu_state(regs, fpu_save); + err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t)); + err |= restore_altstack(&sf->stack); + + if (err) + goto segv; + + regs->pc = pc; + regs->npc = npc; + + err |= __get_user(rwin_save, &sf->rwin_save); + if (!err && rwin_save) { + if (restore_rwin_state(rwin_save)) + goto segv; + } + + set_current_blocked(&set); + return; +segv: + force_sig(SIGSEGV); +} + +static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize) +{ + unsigned long sp = regs->u_regs[UREG_FP]; + + /* + * 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 - framesize))) + return (void __user *) -1L; + + /* This is the X/Open sanctioned signal stack switching. */ + sp = sigsp(sp, ksig) - framesize; + + /* Always align the stack frame. This handles two cases. First, + * sigaltstack need not be mindful of platform specific stack + * alignment. Second, if we took this signal because the stack + * is not aligned properly, we'd like to take the signal cleanly + * and report that. + */ + sp &= ~15UL; + + return (void __user *) sp; +} + +static int setup_frame(struct ksignal *ksig, struct pt_regs *regs, + sigset_t *oldset) +{ + struct signal_frame __user *sf; + int sigframe_size, err, wsaved; + void __user *tail; + + /* 1. Make sure everything is clean */ + synchronize_user_stack(); + + wsaved = current_thread_info()->w_saved; + + sigframe_size = sizeof(*sf); + if (used_math()) + sigframe_size += sizeof(__siginfo_fpu_t); + if (wsaved) + sigframe_size += sizeof(__siginfo_rwin_t); + + sf = (struct signal_frame __user *) + get_sigframe(ksig, regs, sigframe_size); + + if (invalid_frame_pointer(sf, sigframe_size)) { + force_exit_sig(SIGILL); + return -EINVAL; + } + + tail = sf + 1; + + /* 2. Save the current process state */ + err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs)); + + err |= __put_user(0, &sf->extra_size); + + if (used_math()) { + __siginfo_fpu_t __user *fp = tail; + tail += sizeof(*fp); + err |= save_fpu_state(regs, fp); + err |= __put_user(fp, &sf->fpu_save); + } else { + err |= __put_user(0, &sf->fpu_save); + } + if (wsaved) { + __siginfo_rwin_t __user *rwp = tail; + tail += sizeof(*rwp); + err |= save_rwin_state(wsaved, rwp); + err |= __put_user(rwp, &sf->rwin_save); + } else { + err |= __put_user(0, &sf->rwin_save); + } + + err |= __put_user(oldset->sig[0], &sf->info.si_mask); + err |= __copy_to_user(sf->extramask, &oldset->sig[1], + (_NSIG_WORDS - 1) * sizeof(unsigned int)); + if (!wsaved) { + err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP], + sizeof(struct reg_window32)); + } else { + struct reg_window32 *rp; + + rp = ¤t_thread_info()->reg_window[wsaved - 1]; + err |= __copy_to_user(sf, rp, sizeof(struct reg_window32)); + } + if (err) + return err; + + /* 3. signal handler back-trampoline and parameters */ + regs->u_regs[UREG_FP] = (unsigned long) sf; + regs->u_regs[UREG_I0] = ksig->sig; + regs->u_regs[UREG_I1] = (unsigned long) &sf->info; + regs->u_regs[UREG_I2] = (unsigned long) &sf->info; + + /* 4. signal handler */ + regs->pc = (unsigned long) ksig->ka.sa.sa_handler; + regs->npc = (regs->pc + 4); + + /* 5. return to kernel instructions */ + if (ksig->ka.ka_restorer) + regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer; + else { + regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2); + + /* mov __NR_sigreturn, %g1 */ + err |= __put_user(0x821020d8, &sf->insns[0]); + + /* t 0x10 */ + err |= __put_user(0x91d02010, &sf->insns[1]); + if (err) + return err; + + /* Flush instruction space. */ + flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0])); + } + return 0; +} + +static int setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs, + sigset_t *oldset) +{ + struct rt_signal_frame __user *sf; + int sigframe_size, wsaved; + void __user *tail; + unsigned int psr; + int err; + + synchronize_user_stack(); + wsaved = current_thread_info()->w_saved; + sigframe_size = sizeof(*sf); + if (used_math()) + sigframe_size += sizeof(__siginfo_fpu_t); + if (wsaved) + sigframe_size += sizeof(__siginfo_rwin_t); + sf = (struct rt_signal_frame __user *) + get_sigframe(ksig, regs, sigframe_size); + if (invalid_frame_pointer(sf, sigframe_size)) { + force_exit_sig(SIGILL); + return -EINVAL; + } + + tail = sf + 1; + err = __put_user(regs->pc, &sf->regs.pc); + err |= __put_user(regs->npc, &sf->regs.npc); + err |= __put_user(regs->y, &sf->regs.y); + psr = regs->psr; + if (used_math()) + psr |= PSR_EF; + err |= __put_user(psr, &sf->regs.psr); + err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs)); + err |= __put_user(0, &sf->extra_size); + + if (psr & PSR_EF) { + __siginfo_fpu_t __user *fp = tail; + tail += sizeof(*fp); + err |= save_fpu_state(regs, fp); + err |= __put_user(fp, &sf->fpu_save); + } else { + err |= __put_user(0, &sf->fpu_save); + } + if (wsaved) { + __siginfo_rwin_t __user *rwp = tail; + tail += sizeof(*rwp); + err |= save_rwin_state(wsaved, rwp); + err |= __put_user(rwp, &sf->rwin_save); + } else { + err |= __put_user(0, &sf->rwin_save); + } + err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t)); + + /* Setup sigaltstack */ + err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]); + + if (!wsaved) { + err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP], + sizeof(struct reg_window32)); + } else { + struct reg_window32 *rp; + + rp = ¤t_thread_info()->reg_window[wsaved - 1]; + err |= __copy_to_user(sf, rp, sizeof(struct reg_window32)); + } + + err |= copy_siginfo_to_user(&sf->info, &ksig->info); + + if (err) + return err; + + regs->u_regs[UREG_FP] = (unsigned long) sf; + regs->u_regs[UREG_I0] = ksig->sig; + regs->u_regs[UREG_I1] = (unsigned long) &sf->info; + regs->u_regs[UREG_I2] = (unsigned long) &sf->regs; + + regs->pc = (unsigned long) ksig->ka.sa.sa_handler; + regs->npc = (regs->pc + 4); + + if (ksig->ka.ka_restorer) + regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer; + else { + regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2); + + /* mov __NR_rt_sigreturn, %g1 */ + err |= __put_user(0x82102065, &sf->insns[0]); + + /* t 0x10 */ + err |= __put_user(0x91d02010, &sf->insns[1]); + if (err) + return err; + + /* Flush instruction space. */ + flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0])); + } + return 0; +} + +static inline void +handle_signal(struct ksignal *ksig, struct pt_regs *regs) +{ + sigset_t *oldset = sigmask_to_save(); + int err; + + if (ksig->ka.sa.sa_flags & SA_SIGINFO) + err = setup_rt_frame(ksig, regs, oldset); + else + err = setup_frame(ksig, regs, oldset); + signal_setup_done(err, ksig, 0); +} + +static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs, + struct sigaction *sa) +{ + switch(regs->u_regs[UREG_I0]) { + case ERESTART_RESTARTBLOCK: + case ERESTARTNOHAND: + no_system_call_restart: + regs->u_regs[UREG_I0] = EINTR; + regs->psr |= PSR_C; + break; + case ERESTARTSYS: + if (!(sa->sa_flags & SA_RESTART)) + goto no_system_call_restart; + fallthrough; + case ERESTARTNOINTR: + regs->u_regs[UREG_I0] = orig_i0; + regs->pc -= 4; + regs->npc -= 4; + } +} + +/* Note that 'init' is a special process: it doesn't get signals it doesn't + * want to handle. Thus you cannot kill init even with a SIGKILL even by + * mistake. + */ +static void do_signal(struct pt_regs *regs, unsigned long orig_i0) +{ + struct ksignal ksig; + int restart_syscall; + bool has_handler; + + /* It's a lot of work and synchronization to add a new ptrace + * register for GDB to save and restore in order to get + * orig_i0 correct for syscall restarts when debugging. + * + * Although it should be the case that most of the global + * registers are volatile across a system call, glibc already + * depends upon that fact that we preserve them. So we can't + * just use any global register to save away the orig_i0 value. + * + * In particular %g2, %g3, %g4, and %g5 are all assumed to be + * preserved across a system call trap by various pieces of + * code in glibc. + * + * %g7 is used as the "thread register". %g6 is not used in + * any fixed manner. %g6 is used as a scratch register and + * a compiler temporary, but it's value is never used across + * a system call. Therefore %g6 is usable for orig_i0 storage. + */ + if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) + regs->u_regs[UREG_G6] = orig_i0; + + has_handler = get_signal(&ksig); + + /* If the debugger messes with the program counter, it clears + * the software "in syscall" bit, directing us to not perform + * a syscall restart. + */ + restart_syscall = 0; + if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) { + restart_syscall = 1; + orig_i0 = regs->u_regs[UREG_G6]; + } + + if (has_handler) { + if (restart_syscall) + syscall_restart(orig_i0, regs, &ksig.ka.sa); + handle_signal(&ksig, regs); + } else { + if (restart_syscall) { + switch (regs->u_regs[UREG_I0]) { + case ERESTARTNOHAND: + case ERESTARTSYS: + case ERESTARTNOINTR: + /* replay the system call when we are done */ + regs->u_regs[UREG_I0] = orig_i0; + regs->pc -= 4; + regs->npc -= 4; + pt_regs_clear_syscall(regs); + fallthrough; + case ERESTART_RESTARTBLOCK: + regs->u_regs[UREG_G1] = __NR_restart_syscall; + regs->pc -= 4; + regs->npc -= 4; + pt_regs_clear_syscall(regs); + } + } + restore_saved_sigmask(); + } +} + +void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, + unsigned long thread_info_flags) +{ + if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) + do_signal(regs, orig_i0); + if (thread_info_flags & _TIF_NOTIFY_RESUME) + resume_user_mode_work(regs); +} + +asmlinkage int do_sys_sigstack(struct sigstack __user *ssptr, + struct sigstack __user *ossptr, + unsigned long sp) +{ + int ret = -EFAULT; + + /* First see if old state is wanted. */ + if (ossptr) { + if (put_user(current->sas_ss_sp + current->sas_ss_size, + &ossptr->the_stack) || + __put_user(on_sig_stack(sp), &ossptr->cur_status)) + goto out; + } + + /* Now see if we want to update the new state. */ + if (ssptr) { + char *ss_sp; + + if (get_user(ss_sp, &ssptr->the_stack)) + goto out; + /* If the current stack was set with sigaltstack, don't + swap stacks while we are on it. */ + ret = -EPERM; + if (current->sas_ss_sp && on_sig_stack(sp)) + goto out; + + /* Since we don't know the extent of the stack, and we don't + track onstack-ness, but rather calculate it, we must + presume a size. Ho hum this interface is lossy. */ + current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ; + current->sas_ss_size = SIGSTKSZ; + } + ret = 0; +out: + return ret; +} -- cgit v1.2.3