diff options
Diffstat (limited to 'arch/ppc64/kernel/signal32.c')
| -rw-r--r-- | arch/ppc64/kernel/signal32.c | 989 |
1 files changed, 989 insertions, 0 deletions
diff --git a/arch/ppc64/kernel/signal32.c b/arch/ppc64/kernel/signal32.c new file mode 100644 index 000000000000..b0e167db6af9 --- /dev/null +++ b/arch/ppc64/kernel/signal32.c @@ -0,0 +1,989 @@ +/* + * signal32.c: Support 32bit signal syscalls. + * + * Copyright (C) 2001 IBM + * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz) + * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu) + * + * These routines maintain argument size conversion between 32bit and 64bit + * environment. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/config.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/smp.h> +#include <linux/smp_lock.h> +#include <linux/kernel.h> +#include <linux/signal.h> +#include <linux/syscalls.h> +#include <linux/errno.h> +#include <linux/elf.h> +#include <linux/compat.h> +#include <linux/ptrace.h> +#include <asm/ppc32.h> +#include <asm/uaccess.h> +#include <asm/ppcdebug.h> +#include <asm/unistd.h> +#include <asm/cacheflush.h> +#include <asm/vdso.h> + +#define DEBUG_SIG 0 + +#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) + +#define GP_REGS_SIZE32 min(sizeof(elf_gregset_t32), sizeof(struct pt_regs32)) + +/* + * When we have signals to deliver, we set up on the + * user stack, going down from the original stack pointer: + * a sigregs32 struct + * a sigcontext32 struct + * a gap of __SIGNAL_FRAMESIZE32 bytes + * + * Each of these things must be a multiple of 16 bytes in size. + * + */ +struct sigregs32 { + struct mcontext32 mctx; /* all the register values */ + /* + * Programs using the rs6000/xcoff abi can save up to 19 gp + * regs and 18 fp regs below sp before decrementing it. + */ + int abigap[56]; +}; + +/* We use the mc_pad field for the signal return trampoline. */ +#define tramp mc_pad + +/* + * When we have rt signals to deliver, we set up on the + * user stack, going down from the original stack pointer: + * one rt_sigframe32 struct (siginfo + ucontext + ABI gap) + * a gap of __SIGNAL_FRAMESIZE32+16 bytes + * (the +16 is to get the siginfo and ucontext32 in the same + * positions as in older kernels). + * + * Each of these things must be a multiple of 16 bytes in size. + * + */ +struct rt_sigframe32 { + compat_siginfo_t info; + struct ucontext32 uc; + /* + * Programs using the rs6000/xcoff abi can save up to 19 gp + * regs and 18 fp regs below sp before decrementing it. + */ + int abigap[56]; +}; + + +/* + * Common utility functions used by signal and context support + * + */ + +/* + * Restore the user process's signal mask + * (implemented in signal.c) + */ +extern void restore_sigmask(sigset_t *set); + +/* + * Functions for flipping sigsets (thanks to brain dead generic + * implementation that makes things simple for little endian only + */ +static inline void compat_from_sigset(compat_sigset_t *compat, sigset_t *set) +{ + switch (_NSIG_WORDS) { + case 4: compat->sig[5] = set->sig[3] & 0xffffffffull ; + compat->sig[7] = set->sig[3] >> 32; + case 3: compat->sig[4] = set->sig[2] & 0xffffffffull ; + compat->sig[5] = set->sig[2] >> 32; + case 2: compat->sig[2] = set->sig[1] & 0xffffffffull ; + compat->sig[3] = set->sig[1] >> 32; + case 1: compat->sig[0] = set->sig[0] & 0xffffffffull ; + compat->sig[1] = set->sig[0] >> 32; + } +} + +static inline void sigset_from_compat(sigset_t *set, compat_sigset_t *compat) +{ + switch (_NSIG_WORDS) { + case 4: set->sig[3] = compat->sig[6] | (((long)compat->sig[7]) << 32); + case 3: set->sig[2] = compat->sig[4] | (((long)compat->sig[5]) << 32); + case 2: set->sig[1] = compat->sig[2] | (((long)compat->sig[3]) << 32); + case 1: set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32); + } +} + + +/* + * Save the current user registers on the user stack. + * We only save the altivec registers if the process has used + * altivec instructions at some point. + */ +static int save_user_regs(struct pt_regs *regs, struct mcontext32 __user *frame, int sigret) +{ + elf_greg_t64 *gregs = (elf_greg_t64 *)regs; + int i, err = 0; + + /* Make sure floating point registers are stored in regs */ + flush_fp_to_thread(current); + + /* save general and floating-point registers */ + for (i = 0; i <= PT_RESULT; i ++) + err |= __put_user((unsigned int)gregs[i], &frame->mc_gregs[i]); + err |= __copy_to_user(&frame->mc_fregs, current->thread.fpr, + ELF_NFPREG * sizeof(double)); + if (err) + return 1; + + current->thread.fpscr = 0; /* turn off all fp exceptions */ + +#ifdef CONFIG_ALTIVEC + /* save altivec registers */ + if (current->thread.used_vr) { + flush_altivec_to_thread(current); + if (__copy_to_user(&frame->mc_vregs, current->thread.vr, + ELF_NVRREG32 * sizeof(vector128))) + return 1; + /* set MSR_VEC in the saved MSR value to indicate that + frame->mc_vregs contains valid data */ + if (__put_user(regs->msr | MSR_VEC, &frame->mc_gregs[PT_MSR])) + return 1; + } + /* else assert((regs->msr & MSR_VEC) == 0) */ + + /* We always copy to/from vrsave, it's 0 if we don't have or don't + * use altivec. Since VSCR only contains 32 bits saved in the least + * significant bits of a vector, we "cheat" and stuff VRSAVE in the + * most significant bits of that same vector. --BenH + */ + if (__put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32])) + return 1; +#endif /* CONFIG_ALTIVEC */ + + if (sigret) { + /* Set up the sigreturn trampoline: li r0,sigret; sc */ + if (__put_user(0x38000000UL + sigret, &frame->tramp[0]) + || __put_user(0x44000002UL, &frame->tramp[1])) + return 1; + flush_icache_range((unsigned long) &frame->tramp[0], + (unsigned long) &frame->tramp[2]); + } + + return 0; +} + +/* + * Restore the current user register values from the user stack, + * (except for MSR). + */ +static long restore_user_regs(struct pt_regs *regs, + struct mcontext32 __user *sr, int sig) +{ + elf_greg_t64 *gregs = (elf_greg_t64 *)regs; + int i; + long err = 0; + unsigned int save_r2 = 0; +#ifdef CONFIG_ALTIVEC + unsigned long msr; +#endif + + /* + * restore general registers but not including MSR or SOFTE. Also + * take care of keeping r2 (TLS) intact if not a signal + */ + if (!sig) + save_r2 = (unsigned int)regs->gpr[2]; + for (i = 0; i <= PT_RESULT; i++) { + if ((i == PT_MSR) || (i == PT_SOFTE)) + continue; + err |= __get_user(gregs[i], &sr->mc_gregs[i]); + } + if (!sig) + regs->gpr[2] = (unsigned long) save_r2; + if (err) + return 1; + + /* force the process to reload the FP registers from + current->thread when it next does FP instructions */ + regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1); + if (__copy_from_user(current->thread.fpr, &sr->mc_fregs, + sizeof(sr->mc_fregs))) + return 1; + +#ifdef CONFIG_ALTIVEC + /* force the process to reload the altivec registers from + current->thread when it next does altivec instructions */ + regs->msr &= ~MSR_VEC; + if (!__get_user(msr, &sr->mc_gregs[PT_MSR]) && (msr & MSR_VEC) != 0) { + /* restore altivec registers from the stack */ + if (__copy_from_user(current->thread.vr, &sr->mc_vregs, + sizeof(sr->mc_vregs))) + return 1; + } else if (current->thread.used_vr) + memset(current->thread.vr, 0, ELF_NVRREG32 * sizeof(vector128)); + + /* Always get VRSAVE back */ + if (__get_user(current->thread.vrsave, (u32 __user *)&sr->mc_vregs[32])) + return 1; +#endif /* CONFIG_ALTIVEC */ + +#ifndef CONFIG_SMP + preempt_disable(); + if (last_task_used_math == current) + last_task_used_math = NULL; + if (last_task_used_altivec == current) + last_task_used_altivec = NULL; + preempt_enable(); +#endif + return 0; +} + + +/* + * Start of nonRT signal support + * + * sigset_t is 32 bits for non-rt signals + * + * System Calls + * sigaction sys32_sigaction + * sigreturn sys32_sigreturn + * + * Note sigsuspend has no special 32 bit routine - uses the 64 bit routine + * + * Other routines + * setup_frame32 + */ + +/* + * Atomically swap in the new signal mask, and wait for a signal. + */ +long sys32_sigsuspend(old_sigset_t mask, int p2, int p3, int p4, int p6, int p7, + struct pt_regs *regs) +{ + sigset_t saveset; + + mask &= _BLOCKABLE; + spin_lock_irq(¤t->sighand->siglock); + saveset = current->blocked; + siginitset(¤t->blocked, mask); + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + regs->result = -EINTR; + regs->gpr[3] = EINTR; + regs->ccr |= 0x10000000; + while (1) { + current->state = TASK_INTERRUPTIBLE; + schedule(); + if (do_signal32(&saveset, regs)) + /* + * Returning 0 means we return to userspace via + * ret_from_except and thus restore all user + * registers from *regs. This is what we need + * to do when a signal has been delivered. + */ + return 0; + } +} + +long sys32_sigaction(int sig, struct old_sigaction32 __user *act, + struct old_sigaction32 __user *oact) +{ + struct k_sigaction new_ka, old_ka; + int ret; + + if (sig < 0) + sig = -sig; + + if (act) { + compat_old_sigset_t mask; + compat_uptr_t handler, restorer; + + if (get_user(handler, &act->sa_handler) || + __get_user(restorer, &act->sa_restorer) || + __get_user(new_ka.sa.sa_flags, &act->sa_flags) || + __get_user(mask, &act->sa_mask)) + return -EFAULT; + new_ka.sa.sa_handler = compat_ptr(handler); + new_ka.sa.sa_restorer = compat_ptr(restorer); + siginitset(&new_ka.sa.sa_mask, mask); + } + + ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); + if (!ret && oact) { + if (put_user((long)old_ka.sa.sa_handler, &oact->sa_handler) || + __put_user((long)old_ka.sa.sa_restorer, &oact->sa_restorer) || + __put_user(old_ka.sa.sa_flags, &oact->sa_flags) || + __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask)) + return -EFAULT; + } + + return ret; +} + + + +/* + * Start of RT signal support + * + * sigset_t is 64 bits for rt signals + * + * System Calls + * sigaction sys32_rt_sigaction + * sigpending sys32_rt_sigpending + * sigprocmask sys32_rt_sigprocmask + * sigreturn sys32_rt_sigreturn + * sigqueueinfo sys32_rt_sigqueueinfo + * sigsuspend sys32_rt_sigsuspend + * + * Other routines + * setup_rt_frame32 + * copy_siginfo_to_user32 + * siginfo32to64 + */ + + +long sys32_rt_sigaction(int sig, const struct sigaction32 __user *act, + struct sigaction32 __user *oact, size_t sigsetsize) +{ + struct k_sigaction new_ka, old_ka; + int ret; + compat_sigset_t set32; + + /* XXX: Don't preclude handling different sized sigset_t's. */ + if (sigsetsize != sizeof(compat_sigset_t)) + return -EINVAL; + + if (act) { + compat_uptr_t handler; + + ret = get_user(handler, &act->sa_handler); + new_ka.sa.sa_handler = compat_ptr(handler); + ret |= __copy_from_user(&set32, &act->sa_mask, + sizeof(compat_sigset_t)); + sigset_from_compat(&new_ka.sa.sa_mask, &set32); + ret |= __get_user(new_ka.sa.sa_flags, &act->sa_flags); + if (ret) + return -EFAULT; + } + + ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); + if (!ret && oact) { + compat_from_sigset(&set32, &old_ka.sa.sa_mask); + ret = put_user((long)old_ka.sa.sa_handler, &oact->sa_handler); + ret |= __copy_to_user(&oact->sa_mask, &set32, + sizeof(compat_sigset_t)); + ret |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags); + } + return ret; +} + +/* + * Note: it is necessary to treat how as an unsigned int, with the + * corresponding cast to a signed int to insure that the proper + * conversion (sign extension) between the register representation + * of a signed int (msr in 32-bit mode) and the register representation + * of a signed int (msr in 64-bit mode) is performed. + */ +long sys32_rt_sigprocmask(u32 how, compat_sigset_t __user *set, + compat_sigset_t __user *oset, size_t sigsetsize) +{ + sigset_t s; + sigset_t __user *up; + compat_sigset_t s32; + int ret; + mm_segment_t old_fs = get_fs(); + + if (set) { + if (copy_from_user (&s32, set, sizeof(compat_sigset_t))) + return -EFAULT; + sigset_from_compat(&s, &s32); + } + + set_fs(KERNEL_DS); + /* This is valid because of the set_fs() */ + up = (sigset_t __user *) &s; + ret = sys_rt_sigprocmask((int)how, set ? up : NULL, oset ? up : NULL, + sigsetsize); + set_fs(old_fs); + if (ret) + return ret; + if (oset) { + compat_from_sigset(&s32, &s); + if (copy_to_user (oset, &s32, sizeof(compat_sigset_t))) + return -EFAULT; + } + return 0; +} + +long sys32_rt_sigpending(compat_sigset_t __user *set, compat_size_t sigsetsize) +{ + sigset_t s; + compat_sigset_t s32; + int ret; + mm_segment_t old_fs = get_fs(); + + set_fs(KERNEL_DS); + /* The __user pointer cast is valid because of the set_fs() */ + ret = sys_rt_sigpending((sigset_t __user *) &s, sigsetsize); + set_fs(old_fs); + if (!ret) { + compat_from_sigset(&s32, &s); + if (copy_to_user (set, &s32, sizeof(compat_sigset_t))) + return -EFAULT; + } + return ret; +} + + +int copy_siginfo_to_user32(struct compat_siginfo __user *d, siginfo_t *s) +{ + int err; + + if (!access_ok (VERIFY_WRITE, d, sizeof(*d))) + return -EFAULT; + + /* If you change siginfo_t structure, please be sure + * this code is fixed accordingly. + * It should never copy any pad contained in the structure + * to avoid security leaks, but must copy the generic + * 3 ints plus the relevant union member. + * This routine must convert siginfo from 64bit to 32bit as well + * at the same time. + */ + err = __put_user(s->si_signo, &d->si_signo); + err |= __put_user(s->si_errno, &d->si_errno); + err |= __put_user((short)s->si_code, &d->si_code); + if (s->si_code < 0) + err |= __copy_to_user(&d->_sifields._pad, &s->_sifields._pad, + SI_PAD_SIZE32); + else switch(s->si_code >> 16) { + case __SI_CHLD >> 16: + err |= __put_user(s->si_pid, &d->si_pid); + err |= __put_user(s->si_uid, &d->si_uid); + err |= __put_user(s->si_utime, &d->si_utime); + err |= __put_user(s->si_stime, &d->si_stime); + err |= __put_user(s->si_status, &d->si_status); + break; + case __SI_FAULT >> 16: + err |= __put_user((unsigned int)(unsigned long)s->si_addr, + &d->si_addr); + break; + case __SI_POLL >> 16: + err |= __put_user(s->si_band, &d->si_band); + err |= __put_user(s->si_fd, &d->si_fd); + break; + case __SI_TIMER >> 16: + err |= __put_user(s->si_tid, &d->si_tid); + err |= __put_user(s->si_overrun, &d->si_overrun); + err |= __put_user(s->si_int, &d->si_int); + break; + case __SI_RT >> 16: /* This is not generated by the kernel as of now. */ + case __SI_MESGQ >> 16: + err |= __put_user(s->si_int, &d->si_int); + /* fallthrough */ + case __SI_KILL >> 16: + default: + err |= __put_user(s->si_pid, &d->si_pid); + err |= __put_user(s->si_uid, &d->si_uid); + break; + } + return err; +} + +/* + * Note: it is necessary to treat pid and sig as unsigned ints, with the + * corresponding cast to a signed int to insure that the proper conversion + * (sign extension) between the register representation of a signed int + * (msr in 32-bit mode) and the register representation of a signed int + * (msr in 64-bit mode) is performed. + */ +long sys32_rt_sigqueueinfo(u32 pid, u32 sig, compat_siginfo_t __user *uinfo) +{ + siginfo_t info; + int ret; + mm_segment_t old_fs = get_fs(); + + if (copy_from_user (&info, uinfo, 3*sizeof(int)) || + copy_from_user (info._sifields._pad, uinfo->_sifields._pad, SI_PAD_SIZE32)) + return -EFAULT; + set_fs (KERNEL_DS); + /* The __user pointer cast is valid becasuse of the set_fs() */ + ret = sys_rt_sigqueueinfo((int)pid, (int)sig, (siginfo_t __user *) &info); + set_fs (old_fs); + return ret; +} + +int sys32_rt_sigsuspend(compat_sigset_t __user * unewset, size_t sigsetsize, int p3, + int p4, int p6, int p7, struct pt_regs *regs) +{ + sigset_t saveset, newset; + compat_sigset_t s32; + + /* XXX: Don't preclude handling different sized sigset_t's. */ + if (sigsetsize != sizeof(sigset_t)) + return -EINVAL; + + if (copy_from_user(&s32, unewset, sizeof(s32))) + return -EFAULT; + + /* + * Swap the 2 words of the 64-bit sigset_t (they are stored + * in the "wrong" endian in 32-bit user storage). + */ + sigset_from_compat(&newset, &s32); + + sigdelsetmask(&newset, ~_BLOCKABLE); + spin_lock_irq(¤t->sighand->siglock); + saveset = current->blocked; + current->blocked = newset; + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + regs->result = -EINTR; + regs->gpr[3] = EINTR; + regs->ccr |= 0x10000000; + while (1) { + current->state = TASK_INTERRUPTIBLE; + schedule(); + if (do_signal32(&saveset, regs)) + /* + * Returning 0 means we return to userspace via + * ret_from_except and thus restore all user + * registers from *regs. This is what we need + * to do when a signal has been delivered. + */ + return 0; + } +} + +/* + * Start Alternate signal stack support + * + * System Calls + * sigaltatck sys32_sigaltstack + */ + +int sys32_sigaltstack(u32 __new, u32 __old, int r5, + int r6, int r7, int r8, struct pt_regs *regs) +{ + stack_32_t __user * newstack = (stack_32_t __user *)(long) __new; + stack_32_t __user * oldstack = (stack_32_t __user *)(long) __old; + stack_t uss, uoss; + int ret; + mm_segment_t old_fs; + unsigned long sp; + compat_uptr_t ss_sp; + + /* + * set sp to the user stack on entry to the system call + * the system call router sets R9 to the saved registers + */ + sp = regs->gpr[1]; + + /* Put new stack info in local 64 bit stack struct */ + if (newstack) { + if (get_user(ss_sp, &newstack->ss_sp) || + __get_user(uss.ss_flags, &newstack->ss_flags) || + __get_user(uss.ss_size, &newstack->ss_size)) + return -EFAULT; + uss.ss_sp = compat_ptr(ss_sp); + } + + old_fs = get_fs(); + set_fs(KERNEL_DS); + /* The __user pointer casts are valid because of the set_fs() */ + ret = do_sigaltstack( + newstack ? (stack_t __user *) &uss : NULL, + oldstack ? (stack_t __user *) &uoss : NULL, + sp); + set_fs(old_fs); + /* Copy the stack information to the user output buffer */ + if (!ret && oldstack && + (put_user((long)uoss.ss_sp, &oldstack->ss_sp) || + __put_user(uoss.ss_flags, &oldstack->ss_flags) || + __put_user(uoss.ss_size, &oldstack->ss_size))) + return -EFAULT; + return ret; +} + + +/* + * Set up a signal frame for a "real-time" signal handler + * (one which gets siginfo). + */ +static int handle_rt_signal32(unsigned long sig, struct k_sigaction *ka, + siginfo_t *info, sigset_t *oldset, + struct pt_regs * regs, unsigned long newsp) +{ + struct rt_sigframe32 __user *rt_sf; + struct mcontext32 __user *frame; + unsigned long origsp = newsp; + compat_sigset_t c_oldset; + + /* Set up Signal Frame */ + /* Put a Real Time Context onto stack */ + newsp -= sizeof(*rt_sf); + rt_sf = (struct rt_sigframe32 __user *)newsp; + + /* create a stack frame for the caller of the handler */ + newsp -= __SIGNAL_FRAMESIZE32 + 16; + + if (!access_ok(VERIFY_WRITE, (void __user *)newsp, origsp - newsp)) + goto badframe; + + compat_from_sigset(&c_oldset, oldset); + + /* Put the siginfo & fill in most of the ucontext */ + if (copy_siginfo_to_user32(&rt_sf->info, info) + || __put_user(0, &rt_sf->uc.uc_flags) + || __put_user(0, &rt_sf->uc.uc_link) + || __put_user(current->sas_ss_sp, &rt_sf->uc.uc_stack.ss_sp) + || __put_user(sas_ss_flags(regs->gpr[1]), + &rt_sf->uc.uc_stack.ss_flags) + || __put_user(current->sas_ss_size, &rt_sf->uc.uc_stack.ss_size) + || __put_user((u32)(u64)&rt_sf->uc.uc_mcontext, &rt_sf->uc.uc_regs) + || __copy_to_user(&rt_sf->uc.uc_sigmask, &c_oldset, sizeof(c_oldset))) + goto badframe; + + /* Save user registers on the stack */ + frame = &rt_sf->uc.uc_mcontext; + if (put_user(regs->gpr[1], (unsigned long __user *)newsp)) + goto badframe; + + if (vdso32_rt_sigtramp && current->thread.vdso_base) { + if (save_user_regs(regs, frame, 0)) + goto badframe; + regs->link = current->thread.vdso_base + vdso32_rt_sigtramp; + } else { + if (save_user_regs(regs, frame, __NR_rt_sigreturn)) + goto badframe; + regs->link = (unsigned long) frame->tramp; + } + regs->gpr[1] = (unsigned long) newsp; + regs->gpr[3] = sig; + regs->gpr[4] = (unsigned long) &rt_sf->info; + regs->gpr[5] = (unsigned long) &rt_sf->uc; + regs->gpr[6] = (unsigned long) rt_sf; + regs->nip = (unsigned long) ka->sa.sa_handler; + regs->trap = 0; + regs->result = 0; + + if (test_thread_flag(TIF_SINGLESTEP)) + ptrace_notify(SIGTRAP); + + return 1; + +badframe: +#if DEBUG_SIG + printk("badframe in handle_rt_signal, regs=%p frame=%p newsp=%lx\n", + regs, frame, newsp); +#endif + force_sigsegv(sig, current); + return 0; +} + +static long do_setcontext32(struct ucontext32 __user *ucp, struct pt_regs *regs, int sig) +{ + compat_sigset_t c_set; + sigset_t set; + u32 mcp; + + if (__copy_from_user(&c_set, &ucp->uc_sigmask, sizeof(c_set)) + || __get_user(mcp, &ucp->uc_regs)) + return -EFAULT; + sigset_from_compat(&set, &c_set); + restore_sigmask(&set); + if (restore_user_regs(regs, (struct mcontext32 __user *)(u64)mcp, sig)) + return -EFAULT; + + return 0; +} + +/* + * Handle {get,set,swap}_context operations for 32 bits processes + */ + +long sys32_swapcontext(struct ucontext32 __user *old_ctx, + struct ucontext32 __user *new_ctx, + int ctx_size, int r6, int r7, int r8, struct pt_regs *regs) +{ + unsigned char tmp; + compat_sigset_t c_set; + + /* Context size is for future use. Right now, we only make sure + * we are passed something we understand + */ + if (ctx_size < sizeof(struct ucontext32)) + return -EINVAL; + + if (old_ctx != NULL) { + compat_from_sigset(&c_set, ¤t->blocked); + if (!access_ok(VERIFY_WRITE, old_ctx, sizeof(*old_ctx)) + || save_user_regs(regs, &old_ctx->uc_mcontext, 0) + || __copy_to_user(&old_ctx->uc_sigmask, &c_set, sizeof(c_set)) + || __put_user((u32)(u64)&old_ctx->uc_mcontext, &old_ctx->uc_regs)) + return -EFAULT; + } + if (new_ctx == NULL) + return 0; + if (!access_ok(VERIFY_READ, new_ctx, sizeof(*new_ctx)) + || __get_user(tmp, (u8 __user *) new_ctx) + || __get_user(tmp, (u8 __user *) (new_ctx + 1) - 1)) + return -EFAULT; + + /* + * If we get a fault copying the context into the kernel's + * image of the user's registers, we can't just return -EFAULT + * because the user's registers will be corrupted. For instance + * the NIP value may have been updated but not some of the + * other registers. Given that we have done the access_ok + * and successfully read the first and last bytes of the region + * above, this should only happen in an out-of-memory situation + * or if another thread unmaps the region containing the context. + * We kill the task with a SIGSEGV in this situation. + */ + if (do_setcontext32(new_ctx, regs, 0)) + do_exit(SIGSEGV); + + return 0; +} + +long sys32_rt_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8, + struct pt_regs *regs) +{ + struct rt_sigframe32 __user *rt_sf; + int ret; + + + /* Always make any pending restarted system calls return -EINTR */ + current_thread_info()->restart_block.fn = do_no_restart_syscall; + + rt_sf = (struct rt_sigframe32 __user *) + (regs->gpr[1] + __SIGNAL_FRAMESIZE32 + 16); + if (!access_ok(VERIFY_READ, rt_sf, sizeof(*rt_sf))) + goto bad; + if (do_setcontext32(&rt_sf->uc, regs, 1)) + goto bad; + + /* + * It's not clear whether or why it is desirable to save the + * sigaltstack setting on signal delivery and restore it on + * signal return. But other architectures do this and we have + * always done it up until now so it is probably better not to + * change it. -- paulus + * We use the sys32_ version that does the 32/64 bits conversion + * and takes userland pointer directly. What about error checking ? + * nobody does any... + */ + sys32_sigaltstack((u32)(u64)&rt_sf->uc.uc_stack, 0, 0, 0, 0, 0, regs); + + ret = regs->result; + + return ret; + + bad: + force_sig(SIGSEGV, current); + return 0; +} + + +/* + * OK, we're invoking a handler + */ +static int handle_signal32(unsigned long sig, struct k_sigaction *ka, + siginfo_t *info, sigset_t *oldset, + struct pt_regs * regs, unsigned long newsp) +{ + struct sigcontext32 __user *sc; + struct sigregs32 __user *frame; + unsigned long origsp = newsp; + + /* Set up Signal Frame */ + newsp -= sizeof(struct sigregs32); + frame = (struct sigregs32 __user *) newsp; + + /* Put a sigcontext on the stack */ + newsp -= sizeof(*sc); + sc = (struct sigcontext32 __user *) newsp; + + /* create a stack frame for the caller of the handler */ + newsp -= __SIGNAL_FRAMESIZE32; + + if (!access_ok(VERIFY_WRITE, (void __user *) newsp, origsp - newsp)) + goto badframe; + +#if _NSIG != 64 +#error "Please adjust handle_signal32()" +#endif + if (__put_user((u32)(u64)ka->sa.sa_handler, &sc->handler) + || __put_user(oldset->sig[0], &sc->oldmask) + || __put_user((oldset->sig[0] >> 32), &sc->_unused[3]) + || __put_user((u32)(u64)frame, &sc->regs) + || __put_user(sig, &sc->signal)) + goto badframe; + + if (vdso32_sigtramp && current->thread.vdso_base) { + if (save_user_regs(regs, &frame->mctx, 0)) + goto badframe; + regs->link = current->thread.vdso_base + vdso32_sigtramp; + } else { + if (save_user_regs(regs, &frame->mctx, __NR_sigreturn)) + goto badframe; + regs->link = (unsigned long) frame->mctx.tramp; + } + + if (put_user(regs->gpr[1], (unsigned long __user *)newsp)) + goto badframe; + regs->gpr[1] = (unsigned long) newsp; + regs->gpr[3] = sig; + regs->gpr[4] = (unsigned long) sc; + regs->nip = (unsigned long) ka->sa.sa_handler; + regs->trap = 0; + regs->result = 0; + + if (test_thread_flag(TIF_SINGLESTEP)) + ptrace_notify(SIGTRAP); + + return 1; + +badframe: +#if DEBUG_SIG + printk("badframe in handle_signal, regs=%p frame=%x newsp=%x\n", + regs, frame, *newspp); +#endif + force_sigsegv(sig, current); + return 0; +} + +/* + * Do a signal return; undo the signal stack. + */ +long sys32_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8, + struct pt_regs *regs) +{ + struct sigcontext32 __user *sc; + struct sigcontext32 sigctx; + struct mcontext32 __user *sr; + sigset_t set; + int ret; + + /* Always make any pending restarted system calls return -EINTR */ + current_thread_info()->restart_block.fn = do_no_restart_syscall; + + sc = (struct sigcontext32 __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE32); + if (copy_from_user(&sigctx, sc, sizeof(sigctx))) + goto badframe; + + /* + * Note that PPC32 puts the upper 32 bits of the sigmask in the + * unused part of the signal stackframe + */ + set.sig[0] = sigctx.oldmask + ((long)(sigctx._unused[3]) << 32); + restore_sigmask(&set); + + sr = (struct mcontext32 __user *)(u64)sigctx.regs; + if (!access_ok(VERIFY_READ, sr, sizeof(*sr)) + || restore_user_regs(regs, sr, 1)) + goto badframe; + + ret = regs->result; + return ret; + +badframe: + force_sig(SIGSEGV, current); + return 0; +} + + + +/* + * Start of do_signal32 routine + * + * This routine gets control when a pending signal needs to be processed + * in the 32 bit target thread - + * + * It handles both rt and non-rt signals + */ + +/* + * 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. + */ + +int do_signal32(sigset_t *oldset, struct pt_regs *regs) +{ + siginfo_t info; + unsigned int frame, newsp; + int signr, ret; + struct k_sigaction ka; + + if (!oldset) + oldset = ¤t->blocked; + + newsp = frame = 0; + + signr = get_signal_to_deliver(&info, &ka, regs, NULL); + + if (TRAP(regs) == 0x0C00 /* System Call! */ + && regs->ccr & 0x10000000 /* error signalled */ + && ((ret = regs->gpr[3]) == ERESTARTSYS + || ret == ERESTARTNOHAND || ret == ERESTARTNOINTR + || ret == ERESTART_RESTARTBLOCK)) { + + if (signr > 0 + && (ret == ERESTARTNOHAND || ret == ERESTART_RESTARTBLOCK + || (ret == ERESTARTSYS + && !(ka.sa.sa_flags & SA_RESTART)))) { + /* make the system call return an EINTR error */ + regs->result = -EINTR; + regs->gpr[3] = EINTR; + /* note that the cr0.SO bit is already set */ + } else { + regs->nip -= 4; /* Back up & retry system call */ + regs->result = 0; + regs->trap = 0; + if (ret == ERESTART_RESTARTBLOCK) + regs->gpr[0] = __NR_restart_syscall; + else + regs->gpr[3] = regs->orig_gpr3; + } + } + + if (signr == 0) + return 0; /* no signals delivered */ + + if ((ka.sa.sa_flags & SA_ONSTACK) && current->sas_ss_size + && (!on_sig_stack(regs->gpr[1]))) + newsp = (current->sas_ss_sp + current->sas_ss_size); + else + newsp = regs->gpr[1]; + newsp &= ~0xfUL; + + /* Whee! Actually deliver the signal. */ + if (ka.sa.sa_flags & SA_SIGINFO) + ret = handle_rt_signal32(signr, &ka, &info, oldset, regs, newsp); + else + ret = handle_signal32(signr, &ka, &info, oldset, regs, newsp); + + if (ret && !(ka.sa.sa_flags & SA_NODEFER)) { + spin_lock_irq(¤t->sighand->siglock); + sigorsets(¤t->blocked, ¤t->blocked, + &ka.sa.sa_mask); + sigaddset(¤t->blocked, signr); + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + } + + return ret; +} |