/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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"; /* * This computes a quad word aligned pointer inside the vmx_reserve array * element. For historical reasons sigcontext might not be quad word aligned, * but the location we write the VMX regs to must be. See the comment in * sigcontext for more detail. */ #ifdef CONFIG_ALTIVEC static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc) { return (elf_vrreg_t __user *) (((unsigned long)sc->vmx_reserve + 15) & ~0xful); } #endif /* * Set up the sigcontext for the signal frame. */ static long setup_sigcontext(struct sigcontext __user *sc, struct task_struct *tsk, 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 = sigcontext_vmx_regs(sc); unsigned long vrsave; #endif struct pt_regs *regs = tsk->thread.regs; unsigned long msr = regs->msr; long err = 0; BUG_ON(tsk != current); #ifdef CONFIG_ALTIVEC err |= __put_user(v_regs, &sc->v_regs); /* save altivec registers */ if (tsk->thread.used_vr) { flush_altivec_to_thread(tsk); /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ err |= __copy_to_user(v_regs, &tsk->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. */ vrsave = 0; if (cpu_has_feature(CPU_FTR_ALTIVEC)) { vrsave = mfspr(SPRN_VRSAVE); tsk->thread.vrsave = vrsave; } err |= __put_user(vrsave, (u32 __user *)&v_regs[33]); #else /* CONFIG_ALTIVEC */ err |= __put_user(0, &sc->v_regs); #endif /* CONFIG_ALTIVEC */ flush_fp_to_thread(tsk); /* copy fpr regs and fpscr */ err |= copy_fpr_to_user(&sc->fp_regs, tsk); /* * 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 (tsk->thread.used_vsr && ctx_has_vsx_region) { flush_vsx_to_thread(tsk); v_regs += ELF_NVRREG; err |= copy_vsx_to_user(v_regs, tsk); /* 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 task_struct *tsk, 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 = sigcontext_vmx_regs(sc); elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc); #endif struct pt_regs *regs = tsk->thread.regs; unsigned long msr = tsk->thread.ckpt_regs.msr; long err = 0; BUG_ON(tsk != current); 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; #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 (tsk->thread.used_vr) { /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ err |= __copy_to_user(v_regs, &tsk->thread.ckvr_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, &tsk->thread.vr_state, 33 * sizeof(vector128)); else err |= __copy_to_user(tm_v_regs, &tsk->thread.ckvr_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)) tsk->thread.ckvrsave = mfspr(SPRN_VRSAVE); err |= __put_user(tsk->thread.ckvrsave, (u32 __user *)&v_regs[33]); if (msr & MSR_VEC) err |= __put_user(tsk->thread.vrsave, (u32 __user *)&tm_v_regs[33]); else err |= __put_user(tsk->thread.ckvrsave, (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_ckfpr_to_user(&sc->fp_regs, tsk); if (msr & MSR_FP) err |= copy_fpr_to_user(&tm_sc->fp_regs, tsk); else err |= copy_ckfpr_to_user(&tm_sc->fp_regs, tsk); #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 (tsk->thread.used_vsr) { v_regs += ELF_NVRREG; tm_v_regs += ELF_NVRREG; err |= copy_ckvsx_to_user(v_regs, tsk); if (msr & MSR_VSX) err |= copy_vsx_to_user(tm_v_regs, tsk); else err |= copy_ckvsx_to_user(tm_v_regs, tsk); /* 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, &tsk->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 task_struct *tsk, 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; struct pt_regs *regs = tsk->thread.regs; #ifdef CONFIG_VSX int i; #endif BUG_ON(tsk != current); /* 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); /* * Force reload of FP/VEC. * This has to be done before copying stuff into tsk->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(&tsk->thread.vr_state, v_regs, 33 * sizeof(vector128)); tsk->thread.used_vr = true; } else if (tsk->thread.used_vr) { memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128)); } /* Always get VRSAVE back */ if (v_regs != NULL) err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]); else tsk->thread.vrsave = 0; if (cpu_has_feature(CPU_FTR_ALTIVEC)) mtspr(SPRN_VRSAVE, tsk->thread.vrsave); #endif /* CONFIG_ALTIVEC */ /* restore floating point */ err |= copy_fpr_from_user(tsk, &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(tsk, v_regs); tsk->thread.used_vsr = true; } else { for (i = 0; i < 32 ; i++) tsk->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 task_struct *tsk, 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; struct pt_regs *regs = tsk->thread.regs; #ifdef CONFIG_VSX int i; #endif BUG_ON(tsk != current); /* copy the GPRs */ err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr)); err |= __copy_from_user(&tsk->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(tsk->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]); /* Don't allow reserved mode. */ if (MSR_TM_RESV(msr)) return -EINVAL; /* 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(tsk->thread.ckpt_regs.ctr, &sc->gp_regs[PT_CTR]); err |= __get_user(tsk->thread.ckpt_regs.link, &sc->gp_regs[PT_LNK]); err |= __get_user(tsk->thread.ckpt_regs.xer, &sc->gp_regs[PT_XER]); err |= __get_user(tsk->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]); /* * Force reload of FP/VEC. * This has to be done before copying stuff into tsk->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(&tsk->thread.ckvr_state, v_regs, 33 * sizeof(vector128)); err |= __copy_from_user(&tsk->thread.vr_state, tm_v_regs, 33 * sizeof(vector128)); current->thread.used_vr = true; } else if (tsk->thread.used_vr) { memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128)); memset(&tsk->thread.ckvr_state, 0, 33 * sizeof(vector128)); } /* Always get VRSAVE back */ if (v_regs != NULL && tm_v_regs != NULL) { err |= __get_user(tsk->thread.ckvrsave, (u32 __user *)&v_regs[33]); err |= __get_user(tsk->thread.vrsave, (u32 __user *)&tm_v_regs[33]); } else { tsk->thread.vrsave = 0; tsk->thread.ckvrsave = 0; } if (cpu_has_feature(CPU_FTR_ALTIVEC)) mtspr(SPRN_VRSAVE, tsk->thread.vrsave); #endif /* CONFIG_ALTIVEC */ /* restore floating point */ err |= copy_fpr_from_user(tsk, &tm_sc->fp_regs); err |= copy_ckfpr_from_user(tsk, &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(tsk, tm_v_regs); err |= copy_ckvsx_from_user(tsk, v_regs); tsk->thread.used_vsr = true; } else { for (i = 0; i < 32 ; i++) { tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; tsk->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0; } } #endif tm_enable(); /* Make sure the transaction is marked as failed */ tsk->thread.tm_texasr |= TEXASR_FS; /* * Disabling preemption, since it is unsafe to be preempted * with MSR[TS] set without recheckpointing. */ preempt_disable(); /* pull in MSR TS bits from user context */ regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK); /* * Ensure that TM is enabled in regs->msr before we leave the signal * handler. It could be the case that (a) user disabled the TM bit * through the manipulation of the MSR bits in uc_mcontext or (b) the * TM bit was disabled because a sufficient number of context switches * happened whilst in the signal handler and load_tm overflowed, * disabling the TM bit. In either case we can end up with an illegal * TM state leading to a TM Bad Thing when we return to userspace. * * CAUTION: * After regs->MSR[TS] being updated, make sure that get_user(), * put_user() or similar functions are *not* called. These * functions can generate page faults which will cause the process * to be de-scheduled with MSR[TS] set but without calling * tm_recheckpoint(). This can cause a bug. */ regs->msr |= MSR_TM; /* This loads the checkpointed FP/VEC state, if used */ tm_recheckpoint(&tsk->thread, msr); msr_check_and_set(msr & (MSR_FP | MSR_VEC)); if (msr & MSR_FP) { load_fp_state(&tsk->thread.fp_state); regs->msr |= (MSR_FP | tsk->thread.fpexc_mode); } if (msr & MSR_VEC) { load_vr_state(&tsk->thread.vr_state); regs->msr |= MSR_VEC; } preempt_enable(); 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; BUG_ON(regs != current->thread.regs); 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, current, 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(current, 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 BUG_ON(current->thread.regs != regs); /* 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 there is a transactional state then throw it away. * The purpose of a sigreturn is to destroy all traces of the * signal frame, this includes any transactional state created * within in. We only check for suspended as we can never be * active in the kernel, we are active, there is nothing better to * do than go ahead and Bad Thing later. * The cause is not important as there will never be a * recheckpoint so it's not user visible. */ if (MSR_TM_SUSPENDED(mfmsr())) tm_reclaim_current(0); 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; /* Trying to start TM on non TM system */ if (!cpu_has_feature(CPU_FTR_TM)) goto badframe; if (__get_user(uc_transact, &uc->uc_link)) goto badframe; if (restore_tm_sigcontexts(current, &uc->uc_mcontext, &uc_transact->uc_mcontext)) goto badframe; } else #endif { /* * Fall through, for non-TM restore * * Unset MSR[TS] on the thread regs since MSR from user * context does not have MSR active, and recheckpoint was * not called since restore_tm_sigcontexts() was not called * also. * * If not unsetting it, the code can RFID to userspace with * MSR[TS] set, but without CPU in the proper state, * causing a TM bad thing. */ current->thread.regs->msr &= ~MSR_TS_MASK; if (restore_sigcontext(current, 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 task_struct *tsk) { struct rt_sigframe __user *frame; unsigned long newsp = 0; long err = 0; struct pt_regs *regs = tsk->thread.regs; BUG_ON(tsk != current); frame = get_sigframe(ksig, get_tm_stackpointer(tsk), 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, tsk, 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, tsk, 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 */ tsk->thread.fp_state.fpscr = 0; /* Set up to return from userspace. */ if (vdso64_rt_sigtramp && tsk->mm->context.vdso_base) { regs->link = tsk->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, tsk->comm, tsk->pid, "setup_rt_frame", (long)frame, regs->nip, regs->link); return 1; }