diff options
Diffstat (limited to 'arch/powerpc/kernel/signal_64.c')
| -rw-r--r-- | arch/powerpc/kernel/signal_64.c | 812 |
1 files changed, 812 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c new file mode 100644 index 000000000..c7c24d2e2 --- /dev/null +++ b/arch/powerpc/kernel/signal_64.c @@ -0,0 +1,812 @@ +/* + * PowerPC version + * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) + * + * Derived from "arch/i386/kernel/signal.c" + * Copyright (C) 1991, 1992 Linus Torvalds + * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson + * + * 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/sched.h> +#include <linux/mm.h> +#include <linux/smp.h> +#include <linux/kernel.h> +#include <linux/signal.h> +#include <linux/errno.h> +#include <linux/wait.h> +#include <linux/unistd.h> +#include <linux/stddef.h> +#include <linux/elf.h> +#include <linux/ptrace.h> +#include <linux/ratelimit.h> + +#include <asm/sigcontext.h> +#include <asm/ucontext.h> +#include <asm/uaccess.h> +#include <asm/pgtable.h> +#include <asm/unistd.h> +#include <asm/cacheflush.h> +#include <asm/syscalls.h> +#include <asm/vdso.h> +#include <asm/switch_to.h> +#include <asm/tm.h> + +#include "signal.h" + + +#define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs)) +#define FP_REGS_SIZE sizeof(elf_fpregset_t) + +#define TRAMP_TRACEBACK 3 +#define TRAMP_SIZE 6 + +/* + * When we have signals to deliver, we set up on the user stack, + * going down from the original stack pointer: + * 1) a rt_sigframe struct which contains the ucontext + * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller + * frame for the signal handler. + */ + +struct rt_sigframe { + /* sys_rt_sigreturn requires the ucontext be the first field */ + struct ucontext uc; +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + struct ucontext uc_transact; +#endif + unsigned long _unused[2]; + unsigned int tramp[TRAMP_SIZE]; + struct siginfo __user *pinfo; + void __user *puc; + struct siginfo info; + /* New 64 bit little-endian ABI allows redzone of 512 bytes below sp */ + char abigap[USER_REDZONE_SIZE]; +} __attribute__ ((aligned (16))); + +static const char fmt32[] = KERN_INFO \ + "%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n"; +static const char fmt64[] = KERN_INFO \ + "%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n"; + +/* + * Set up the sigcontext for the signal frame. + */ + +static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, + int signr, sigset_t *set, unsigned long handler, + int ctx_has_vsx_region) +{ + /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the + * process never used altivec yet (MSR_VEC is zero in pt_regs of + * the context). This is very important because we must ensure we + * don't lose the VRSAVE content that may have been set prior to + * the process doing its first vector operation + * Userland shall check AT_HWCAP to know whether it can rely on the + * v_regs pointer or not + */ +#ifdef CONFIG_ALTIVEC + elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *)(((unsigned long)sc->vmx_reserve + 15) & ~0xful); +#endif + unsigned long msr = regs->msr; + long err = 0; + +#ifdef CONFIG_ALTIVEC + err |= __put_user(v_regs, &sc->v_regs); + + /* save altivec registers */ + if (current->thread.used_vr) { + flush_altivec_to_thread(current); + /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ + err |= __copy_to_user(v_regs, ¤t->thread.vr_state, + 33 * sizeof(vector128)); + /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg) + * contains valid data. + */ + msr |= MSR_VEC; + } + /* We always copy to/from vrsave, it's 0 if we don't have or don't + * use altivec. + */ + if (cpu_has_feature(CPU_FTR_ALTIVEC)) + current->thread.vrsave = mfspr(SPRN_VRSAVE); + err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); +#else /* CONFIG_ALTIVEC */ + err |= __put_user(0, &sc->v_regs); +#endif /* CONFIG_ALTIVEC */ + flush_fp_to_thread(current); + /* copy fpr regs and fpscr */ + err |= copy_fpr_to_user(&sc->fp_regs, current); + + /* + * Clear the MSR VSX bit to indicate there is no valid state attached + * to this context, except in the specific case below where we set it. + */ + msr &= ~MSR_VSX; +#ifdef CONFIG_VSX + /* + * Copy VSX low doubleword to local buffer for formatting, + * then out to userspace. Update v_regs to point after the + * VMX data. + */ + if (current->thread.used_vsr && ctx_has_vsx_region) { + __giveup_vsx(current); + v_regs += ELF_NVRREG; + err |= copy_vsx_to_user(v_regs, current); + /* set MSR_VSX in the MSR value in the frame to + * indicate that sc->vs_reg) contains valid data. + */ + msr |= MSR_VSX; + } +#endif /* CONFIG_VSX */ + err |= __put_user(&sc->gp_regs, &sc->regs); + WARN_ON(!FULL_REGS(regs)); + err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE); + err |= __put_user(msr, &sc->gp_regs[PT_MSR]); + err |= __put_user(signr, &sc->signal); + err |= __put_user(handler, &sc->handler); + if (set != NULL) + err |= __put_user(set->sig[0], &sc->oldmask); + + return err; +} + +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM +/* + * As above, but Transactional Memory is in use, so deliver sigcontexts + * containing checkpointed and transactional register states. + * + * To do this, we treclaim (done before entering here) to gather both sets of + * registers and set up the 'normal' sigcontext registers with rolled-back + * register values such that a simple signal handler sees a correct + * checkpointed register state. If interested, a TM-aware sighandler can + * examine the transactional registers in the 2nd sigcontext to determine the + * real origin of the signal. + */ +static long setup_tm_sigcontexts(struct sigcontext __user *sc, + struct sigcontext __user *tm_sc, + struct pt_regs *regs, + int signr, sigset_t *set, unsigned long handler) +{ + /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the + * process never used altivec yet (MSR_VEC is zero in pt_regs of + * the context). This is very important because we must ensure we + * don't lose the VRSAVE content that may have been set prior to + * the process doing its first vector operation + * Userland shall check AT_HWCAP to know wether it can rely on the + * v_regs pointer or not. + */ +#ifdef CONFIG_ALTIVEC + elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *) + (((unsigned long)sc->vmx_reserve + 15) & ~0xful); + elf_vrreg_t __user *tm_v_regs = (elf_vrreg_t __user *) + (((unsigned long)tm_sc->vmx_reserve + 15) & ~0xful); +#endif + unsigned long msr = regs->msr; + long err = 0; + + BUG_ON(!MSR_TM_ACTIVE(regs->msr)); + + /* Remove TM bits from thread's MSR. The MSR in the sigcontext + * just indicates to userland that we were doing a transaction, but we + * don't want to return in transactional state. This also ensures + * that flush_fp_to_thread won't set TIF_RESTORE_TM again. + */ + regs->msr &= ~MSR_TS_MASK; + + flush_fp_to_thread(current); + +#ifdef CONFIG_ALTIVEC + err |= __put_user(v_regs, &sc->v_regs); + err |= __put_user(tm_v_regs, &tm_sc->v_regs); + + /* save altivec registers */ + if (current->thread.used_vr) { + flush_altivec_to_thread(current); + /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ + err |= __copy_to_user(v_regs, ¤t->thread.vr_state, + 33 * sizeof(vector128)); + /* If VEC was enabled there are transactional VRs valid too, + * else they're a copy of the checkpointed VRs. + */ + if (msr & MSR_VEC) + err |= __copy_to_user(tm_v_regs, + ¤t->thread.transact_vr, + 33 * sizeof(vector128)); + else + err |= __copy_to_user(tm_v_regs, + ¤t->thread.vr_state, + 33 * sizeof(vector128)); + + /* set MSR_VEC in the MSR value in the frame to indicate + * that sc->v_reg contains valid data. + */ + msr |= MSR_VEC; + } + /* We always copy to/from vrsave, it's 0 if we don't have or don't + * use altivec. + */ + if (cpu_has_feature(CPU_FTR_ALTIVEC)) + current->thread.vrsave = mfspr(SPRN_VRSAVE); + err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); + if (msr & MSR_VEC) + err |= __put_user(current->thread.transact_vrsave, + (u32 __user *)&tm_v_regs[33]); + else + err |= __put_user(current->thread.vrsave, + (u32 __user *)&tm_v_regs[33]); + +#else /* CONFIG_ALTIVEC */ + err |= __put_user(0, &sc->v_regs); + err |= __put_user(0, &tm_sc->v_regs); +#endif /* CONFIG_ALTIVEC */ + + /* copy fpr regs and fpscr */ + err |= copy_fpr_to_user(&sc->fp_regs, current); + if (msr & MSR_FP) + err |= copy_transact_fpr_to_user(&tm_sc->fp_regs, current); + else + err |= copy_fpr_to_user(&tm_sc->fp_regs, current); + +#ifdef CONFIG_VSX + /* + * Copy VSX low doubleword to local buffer for formatting, + * then out to userspace. Update v_regs to point after the + * VMX data. + */ + if (current->thread.used_vsr) { + __giveup_vsx(current); + v_regs += ELF_NVRREG; + tm_v_regs += ELF_NVRREG; + + err |= copy_vsx_to_user(v_regs, current); + + if (msr & MSR_VSX) + err |= copy_transact_vsx_to_user(tm_v_regs, current); + else + err |= copy_vsx_to_user(tm_v_regs, current); + + /* set MSR_VSX in the MSR value in the frame to + * indicate that sc->vs_reg) contains valid data. + */ + msr |= MSR_VSX; + } +#endif /* CONFIG_VSX */ + + err |= __put_user(&sc->gp_regs, &sc->regs); + err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs); + WARN_ON(!FULL_REGS(regs)); + err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE); + err |= __copy_to_user(&sc->gp_regs, + ¤t->thread.ckpt_regs, GP_REGS_SIZE); + err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]); + err |= __put_user(msr, &sc->gp_regs[PT_MSR]); + err |= __put_user(signr, &sc->signal); + err |= __put_user(handler, &sc->handler); + if (set != NULL) + err |= __put_user(set->sig[0], &sc->oldmask); + + return err; +} +#endif + +/* + * Restore the sigcontext from the signal frame. + */ + +static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig, + struct sigcontext __user *sc) +{ +#ifdef CONFIG_ALTIVEC + elf_vrreg_t __user *v_regs; +#endif + unsigned long err = 0; + unsigned long save_r13 = 0; + unsigned long msr; +#ifdef CONFIG_VSX + int i; +#endif + + /* If this is not a signal return, we preserve the TLS in r13 */ + if (!sig) + save_r13 = regs->gpr[13]; + + /* copy the GPRs */ + err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr)); + err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]); + /* get MSR separately, transfer the LE bit if doing signal return */ + err |= __get_user(msr, &sc->gp_regs[PT_MSR]); + if (sig) + regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); + err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]); + err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]); + err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]); + err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]); + err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]); + /* skip SOFTE */ + regs->trap = 0; + err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]); + err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]); + err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]); + + if (!sig) + regs->gpr[13] = save_r13; + if (set != NULL) + err |= __get_user(set->sig[0], &sc->oldmask); + + /* + * Do this before updating the thread state in + * current->thread.fpr/vr. That way, if we get preempted + * and another task grabs the FPU/Altivec, it won't be + * tempted to save the current CPU state into the thread_struct + * and corrupt what we are writing there. + */ + discard_lazy_cpu_state(); + + /* + * Force reload of FP/VEC. + * This has to be done before copying stuff into current->thread.fpr/vr + * for the reasons explained in the previous comment. + */ + regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX); + +#ifdef CONFIG_ALTIVEC + err |= __get_user(v_regs, &sc->v_regs); + if (err) + return err; + if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128))) + return -EFAULT; + /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ + if (v_regs != NULL && (msr & MSR_VEC) != 0) + err |= __copy_from_user(¤t->thread.vr_state, v_regs, + 33 * sizeof(vector128)); + else if (current->thread.used_vr) + memset(¤t->thread.vr_state, 0, 33 * sizeof(vector128)); + /* Always get VRSAVE back */ + if (v_regs != NULL) + err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); + else + current->thread.vrsave = 0; + if (cpu_has_feature(CPU_FTR_ALTIVEC)) + mtspr(SPRN_VRSAVE, current->thread.vrsave); +#endif /* CONFIG_ALTIVEC */ + /* restore floating point */ + err |= copy_fpr_from_user(current, &sc->fp_regs); +#ifdef CONFIG_VSX + /* + * Get additional VSX data. Update v_regs to point after the + * VMX data. Copy VSX low doubleword from userspace to local + * buffer for formatting, then into the taskstruct. + */ + v_regs += ELF_NVRREG; + if ((msr & MSR_VSX) != 0) + err |= copy_vsx_from_user(current, v_regs); + else + for (i = 0; i < 32 ; i++) + current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; +#endif + return err; +} + +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM +/* + * Restore the two sigcontexts from the frame of a transactional processes. + */ + +static long restore_tm_sigcontexts(struct pt_regs *regs, + struct sigcontext __user *sc, + struct sigcontext __user *tm_sc) +{ +#ifdef CONFIG_ALTIVEC + elf_vrreg_t __user *v_regs, *tm_v_regs; +#endif + unsigned long err = 0; + unsigned long msr; +#ifdef CONFIG_VSX + int i; +#endif + /* copy the GPRs */ + err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr)); + err |= __copy_from_user(¤t->thread.ckpt_regs, sc->gp_regs, + sizeof(regs->gpr)); + + /* + * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP. + * TEXASR was set by the signal delivery reclaim, as was TFIAR. + * Users doing anything abhorrent like thread-switching w/ signals for + * TM-Suspended code will have to back TEXASR/TFIAR up themselves. + * For the case of getting a signal and simply returning from it, + * we don't need to re-copy them here. + */ + err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]); + err |= __get_user(current->thread.tm_tfhar, &sc->gp_regs[PT_NIP]); + + /* get MSR separately, transfer the LE bit if doing signal return */ + err |= __get_user(msr, &sc->gp_regs[PT_MSR]); + /* pull in MSR TM from user context */ + regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK); + + /* pull in MSR LE from user context */ + regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); + + /* The following non-GPR non-FPR non-VR state is also checkpointed: */ + err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]); + err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]); + err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]); + err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]); + err |= __get_user(current->thread.ckpt_regs.ctr, + &sc->gp_regs[PT_CTR]); + err |= __get_user(current->thread.ckpt_regs.link, + &sc->gp_regs[PT_LNK]); + err |= __get_user(current->thread.ckpt_regs.xer, + &sc->gp_regs[PT_XER]); + err |= __get_user(current->thread.ckpt_regs.ccr, + &sc->gp_regs[PT_CCR]); + + /* These regs are not checkpointed; they can go in 'regs'. */ + err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]); + err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]); + err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]); + err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]); + + /* + * Do this before updating the thread state in + * current->thread.fpr/vr. That way, if we get preempted + * and another task grabs the FPU/Altivec, it won't be + * tempted to save the current CPU state into the thread_struct + * and corrupt what we are writing there. + */ + discard_lazy_cpu_state(); + + /* + * Force reload of FP/VEC. + * This has to be done before copying stuff into current->thread.fpr/vr + * for the reasons explained in the previous comment. + */ + regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX); + +#ifdef CONFIG_ALTIVEC + err |= __get_user(v_regs, &sc->v_regs); + err |= __get_user(tm_v_regs, &tm_sc->v_regs); + if (err) + return err; + if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128))) + return -EFAULT; + if (tm_v_regs && !access_ok(VERIFY_READ, + tm_v_regs, 34 * sizeof(vector128))) + return -EFAULT; + /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ + if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) { + err |= __copy_from_user(¤t->thread.vr_state, v_regs, + 33 * sizeof(vector128)); + err |= __copy_from_user(¤t->thread.transact_vr, tm_v_regs, + 33 * sizeof(vector128)); + } + else if (current->thread.used_vr) { + memset(¤t->thread.vr_state, 0, 33 * sizeof(vector128)); + memset(¤t->thread.transact_vr, 0, 33 * sizeof(vector128)); + } + /* Always get VRSAVE back */ + if (v_regs != NULL && tm_v_regs != NULL) { + err |= __get_user(current->thread.vrsave, + (u32 __user *)&v_regs[33]); + err |= __get_user(current->thread.transact_vrsave, + (u32 __user *)&tm_v_regs[33]); + } + else { + current->thread.vrsave = 0; + current->thread.transact_vrsave = 0; + } + if (cpu_has_feature(CPU_FTR_ALTIVEC)) + mtspr(SPRN_VRSAVE, current->thread.vrsave); +#endif /* CONFIG_ALTIVEC */ + /* restore floating point */ + err |= copy_fpr_from_user(current, &sc->fp_regs); + err |= copy_transact_fpr_from_user(current, &tm_sc->fp_regs); +#ifdef CONFIG_VSX + /* + * Get additional VSX data. Update v_regs to point after the + * VMX data. Copy VSX low doubleword from userspace to local + * buffer for formatting, then into the taskstruct. + */ + if (v_regs && ((msr & MSR_VSX) != 0)) { + v_regs += ELF_NVRREG; + tm_v_regs += ELF_NVRREG; + err |= copy_vsx_from_user(current, v_regs); + err |= copy_transact_vsx_from_user(current, tm_v_regs); + } else { + for (i = 0; i < 32 ; i++) { + current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; + current->thread.transact_fp.fpr[i][TS_VSRLOWOFFSET] = 0; + } + } +#endif + tm_enable(); + /* Make sure the transaction is marked as failed */ + current->thread.tm_texasr |= TEXASR_FS; + /* This loads the checkpointed FP/VEC state, if used */ + tm_recheckpoint(¤t->thread, msr); + + /* This loads the speculative FP/VEC state, if used */ + if (msr & MSR_FP) { + do_load_up_transact_fpu(¤t->thread); + regs->msr |= (MSR_FP | current->thread.fpexc_mode); + } +#ifdef CONFIG_ALTIVEC + if (msr & MSR_VEC) { + do_load_up_transact_altivec(¤t->thread); + regs->msr |= MSR_VEC; + } +#endif + + return err; +} +#endif + +/* + * Setup the trampoline code on the stack + */ +static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp) +{ + int i; + long err = 0; + + /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */ + err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]); + /* li r0, __NR_[rt_]sigreturn| */ + err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]); + /* sc */ + err |= __put_user(0x44000002UL, &tramp[2]); + + /* Minimal traceback info */ + for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++) + err |= __put_user(0, &tramp[i]); + + if (!err) + flush_icache_range((unsigned long) &tramp[0], + (unsigned long) &tramp[TRAMP_SIZE]); + + return err; +} + +/* + * Userspace code may pass a ucontext which doesn't include VSX added + * at the end. We need to check for this case. + */ +#define UCONTEXTSIZEWITHOUTVSX \ + (sizeof(struct ucontext) - 32*sizeof(long)) + +/* + * Handle {get,set,swap}_context operations + */ +int sys_swapcontext(struct ucontext __user *old_ctx, + struct ucontext __user *new_ctx, + long ctx_size, long r6, long r7, long r8, struct pt_regs *regs) +{ + unsigned char tmp; + sigset_t set; + unsigned long new_msr = 0; + int ctx_has_vsx_region = 0; + + if (new_ctx && + get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR])) + return -EFAULT; + /* + * Check that the context is not smaller than the original + * size (with VMX but without VSX) + */ + if (ctx_size < UCONTEXTSIZEWITHOUTVSX) + return -EINVAL; + /* + * If the new context state sets the MSR VSX bits but + * it doesn't provide VSX state. + */ + if ((ctx_size < sizeof(struct ucontext)) && + (new_msr & MSR_VSX)) + return -EINVAL; + /* Does the context have enough room to store VSX data? */ + if (ctx_size >= sizeof(struct ucontext)) + ctx_has_vsx_region = 1; + + if (old_ctx != NULL) { + if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size) + || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0, + ctx_has_vsx_region) + || __copy_to_user(&old_ctx->uc_sigmask, + ¤t->blocked, sizeof(sigset_t))) + return -EFAULT; + } + if (new_ctx == NULL) + return 0; + if (!access_ok(VERIFY_READ, new_ctx, ctx_size) + || __get_user(tmp, (u8 __user *) new_ctx) + || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 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 (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set))) + do_exit(SIGSEGV); + set_current_blocked(&set); + if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext)) + do_exit(SIGSEGV); + + /* This returns like rt_sigreturn */ + set_thread_flag(TIF_RESTOREALL); + return 0; +} + + +/* + * Do a signal return; undo the signal stack. + */ + +int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5, + unsigned long r6, unsigned long r7, unsigned long r8, + struct pt_regs *regs) +{ + struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1]; + sigset_t set; +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + unsigned long msr; +#endif + + /* Always make any pending restarted system calls return -EINTR */ + current->restart_block.fn = do_no_restart_syscall; + + if (!access_ok(VERIFY_READ, uc, sizeof(*uc))) + goto badframe; + + if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set))) + goto badframe; + set_current_blocked(&set); +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR])) + goto badframe; + if (MSR_TM_ACTIVE(msr)) { + /* We recheckpoint on return. */ + struct ucontext __user *uc_transact; + if (__get_user(uc_transact, &uc->uc_link)) + goto badframe; + if (restore_tm_sigcontexts(regs, &uc->uc_mcontext, + &uc_transact->uc_mcontext)) + goto badframe; + } + else + /* Fall through, for non-TM restore */ +#endif + if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext)) + goto badframe; + + if (restore_altstack(&uc->uc_stack)) + goto badframe; + + set_thread_flag(TIF_RESTOREALL); + return 0; + +badframe: + if (show_unhandled_signals) + printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, + current->comm, current->pid, "rt_sigreturn", + (long)uc, regs->nip, regs->link); + + force_sig(SIGSEGV, current); + return 0; +} + +int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) +{ + struct rt_sigframe __user *frame; + unsigned long newsp = 0; + long err = 0; + + frame = get_sigframe(ksig, get_tm_stackpointer(regs), sizeof(*frame), 0); + if (unlikely(frame == NULL)) + goto badframe; + + err |= __put_user(&frame->info, &frame->pinfo); + err |= __put_user(&frame->uc, &frame->puc); + err |= copy_siginfo_to_user(&frame->info, &ksig->info); + if (err) + goto badframe; + + /* Create the ucontext. */ + err |= __put_user(0, &frame->uc.uc_flags); + err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]); +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + if (MSR_TM_ACTIVE(regs->msr)) { + /* The ucontext_t passed to userland points to the second + * ucontext_t (for transactional state) with its uc_link ptr. + */ + err |= __put_user(&frame->uc_transact, &frame->uc.uc_link); + err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext, + &frame->uc_transact.uc_mcontext, + regs, ksig->sig, + NULL, + (unsigned long)ksig->ka.sa.sa_handler); + } else +#endif + { + err |= __put_user(0, &frame->uc.uc_link); + err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, ksig->sig, + NULL, (unsigned long)ksig->ka.sa.sa_handler, + 1); + } + err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); + if (err) + goto badframe; + + /* Make sure signal handler doesn't get spurious FP exceptions */ + current->thread.fp_state.fpscr = 0; + + /* Set up to return from userspace. */ + if (vdso64_rt_sigtramp && current->mm->context.vdso_base) { + regs->link = current->mm->context.vdso_base + vdso64_rt_sigtramp; + } else { + err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]); + if (err) + goto badframe; + regs->link = (unsigned long) &frame->tramp[0]; + } + + /* Allocate a dummy caller frame for the signal handler. */ + newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE; + err |= put_user(regs->gpr[1], (unsigned long __user *)newsp); + + /* Set up "regs" so we "return" to the signal handler. */ + if (is_elf2_task()) { + regs->nip = (unsigned long) ksig->ka.sa.sa_handler; + regs->gpr[12] = regs->nip; + } else { + /* Handler is *really* a pointer to the function descriptor for + * the signal routine. The first entry in the function + * descriptor is the entry address of signal and the second + * entry is the TOC value we need to use. + */ + func_descr_t __user *funct_desc_ptr = + (func_descr_t __user *) ksig->ka.sa.sa_handler; + + err |= get_user(regs->nip, &funct_desc_ptr->entry); + err |= get_user(regs->gpr[2], &funct_desc_ptr->toc); + } + + /* enter the signal handler in native-endian mode */ + regs->msr &= ~MSR_LE; + regs->msr |= (MSR_KERNEL & MSR_LE); + regs->gpr[1] = newsp; + regs->gpr[3] = ksig->sig; + regs->result = 0; + if (ksig->ka.sa.sa_flags & SA_SIGINFO) { + err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo); + err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc); + regs->gpr[6] = (unsigned long) frame; + } else { + regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext; + } + if (err) + goto badframe; + + return 0; + +badframe: + if (show_unhandled_signals) + printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, + current->comm, current->pid, "setup_rt_frame", + (long)frame, regs->nip, regs->link); + + return 1; +} |