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Diffstat (limited to 'arch/powerpc/kernel/signal_32.c')
| -rw-r--r-- | arch/powerpc/kernel/signal_32.c | 1359 |
1 files changed, 1359 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c new file mode 100644 index 0000000000..7a718ed32b --- /dev/null +++ b/arch/powerpc/kernel/signal_32.c @@ -0,0 +1,1359 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Signal handling for 32bit PPC and 32bit tasks on 64bit PPC + * + * PowerPC version + * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) + * 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) + * + * Derived from "arch/i386/kernel/signal.c" + * Copyright (C) 1991, 1992 Linus Torvalds + * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson + */ + +#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/elf.h> +#include <linux/ptrace.h> +#include <linux/pagemap.h> +#include <linux/ratelimit.h> +#include <linux/syscalls.h> +#ifdef CONFIG_PPC64 +#include <linux/compat.h> +#else +#include <linux/wait.h> +#include <linux/unistd.h> +#include <linux/stddef.h> +#include <linux/tty.h> +#include <linux/binfmts.h> +#endif + +#include <linux/uaccess.h> +#include <asm/cacheflush.h> +#include <asm/syscalls.h> +#include <asm/sigcontext.h> +#include <asm/vdso.h> +#include <asm/switch_to.h> +#include <asm/tm.h> +#include <asm/asm-prototypes.h> +#ifdef CONFIG_PPC64 +#include <asm/syscalls_32.h> +#include <asm/unistd.h> +#else +#include <asm/ucontext.h> +#endif + +#include "signal.h" + + +#ifdef CONFIG_PPC64 +#define old_sigaction old_sigaction32 +#define sigcontext sigcontext32 +#define mcontext mcontext32 +#define ucontext ucontext32 + +/* + * 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) - sizeof(elf_vsrreghalf_t32)) + +/* + * 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. + */ + +#define GP_REGS_SIZE min(sizeof(elf_gregset_t32), sizeof(struct pt_regs32)) +#undef __SIGNAL_FRAMESIZE +#define __SIGNAL_FRAMESIZE __SIGNAL_FRAMESIZE32 +#undef ELF_NVRREG +#define ELF_NVRREG ELF_NVRREG32 + +/* + * Functions for flipping sigsets (thanks to brain dead generic + * implementation that makes things simple for little endian only) + */ +#define unsafe_put_sigset_t unsafe_put_compat_sigset +#define unsafe_get_sigset_t unsafe_get_compat_sigset + +#define to_user_ptr(p) ptr_to_compat(p) +#define from_user_ptr(p) compat_ptr(p) + +static __always_inline int +__unsafe_save_general_regs(struct pt_regs *regs, struct mcontext __user *frame) +{ + elf_greg_t64 *gregs = (elf_greg_t64 *)regs; + int val, i; + + for (i = 0; i <= PT_RESULT; i ++) { + /* Force usr to alway see softe as 1 (interrupts enabled) */ + if (i == PT_SOFTE) + val = 1; + else + val = gregs[i]; + + unsafe_put_user(val, &frame->mc_gregs[i], failed); + } + return 0; + +failed: + return 1; +} + +static __always_inline int +__unsafe_restore_general_regs(struct pt_regs *regs, struct mcontext __user *sr) +{ + elf_greg_t64 *gregs = (elf_greg_t64 *)regs; + int i; + + for (i = 0; i <= PT_RESULT; i++) { + if ((i == PT_MSR) || (i == PT_SOFTE)) + continue; + unsafe_get_user(gregs[i], &sr->mc_gregs[i], failed); + } + return 0; + +failed: + return 1; +} + +#else /* CONFIG_PPC64 */ + +#define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs)) + +#define unsafe_put_sigset_t(uset, set, label) do { \ + sigset_t __user *__us = uset ; \ + const sigset_t *__s = set; \ + \ + unsafe_copy_to_user(__us, __s, sizeof(*__us), label); \ +} while (0) + +#define unsafe_get_sigset_t unsafe_get_user_sigset + +#define to_user_ptr(p) ((unsigned long)(p)) +#define from_user_ptr(p) ((void __user *)(p)) + +static __always_inline int +__unsafe_save_general_regs(struct pt_regs *regs, struct mcontext __user *frame) +{ + unsafe_copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE, failed); + return 0; + +failed: + return 1; +} + +static __always_inline +int __unsafe_restore_general_regs(struct pt_regs *regs, struct mcontext __user *sr) +{ + /* copy up to but not including MSR */ + unsafe_copy_from_user(regs, &sr->mc_gregs, PT_MSR * sizeof(elf_greg_t), failed); + + /* copy from orig_r3 (the word after the MSR) up to the end */ + unsafe_copy_from_user(®s->orig_gpr3, &sr->mc_gregs[PT_ORIG_R3], + GP_REGS_SIZE - PT_ORIG_R3 * sizeof(elf_greg_t), failed); + + return 0; + +failed: + return 1; +} +#endif + +#define unsafe_save_general_regs(regs, frame, label) do { \ + if (__unsafe_save_general_regs(regs, frame)) \ + goto label; \ +} while (0) + +#define unsafe_restore_general_regs(regs, frame, label) do { \ + if (__unsafe_restore_general_regs(regs, frame)) \ + goto label; \ +} while (0) + +/* + * When we have signals to deliver, we set up on the + * user stack, going down from the original stack pointer: + * an ABI gap of 56 words + * an mcontext struct + * a sigcontext struct + * a gap of __SIGNAL_FRAMESIZE bytes + * + * Each of these things must be a multiple of 16 bytes in size. The following + * structure represent all of this except the __SIGNAL_FRAMESIZE gap + * + */ +struct sigframe { + struct sigcontext sctx; /* the sigcontext */ + struct mcontext mctx; /* all the register values */ +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + struct sigcontext sctx_transact; + struct mcontext mctx_transact; +#endif + /* + * 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]; +}; + +/* + * When we have rt signals to deliver, we set up on the + * user stack, going down from the original stack pointer: + * one rt_sigframe struct (siginfo + ucontext + ABI gap) + * a gap of __SIGNAL_FRAMESIZE+16 bytes + * (the +16 is to get the siginfo and ucontext in the same + * positions as in older kernels). + * + * Each of these things must be a multiple of 16 bytes in size. + * + */ +struct rt_sigframe { +#ifdef CONFIG_PPC64 + compat_siginfo_t info; +#else + struct siginfo info; +#endif + struct ucontext uc; +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + struct ucontext uc_transact; +#endif + /* + * 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]; +}; + +unsigned long get_min_sigframe_size_32(void) +{ + return max(sizeof(struct rt_sigframe) + __SIGNAL_FRAMESIZE + 16, + sizeof(struct sigframe) + __SIGNAL_FRAMESIZE); +} + +/* + * Save the current user registers on the user stack. + * We only save the altivec/spe registers if the process has used + * altivec/spe instructions at some point. + */ +static void prepare_save_user_regs(int ctx_has_vsx_region) +{ + /* Make sure floating point registers are stored in regs */ + flush_fp_to_thread(current); +#ifdef CONFIG_ALTIVEC + if (current->thread.used_vr) + flush_altivec_to_thread(current); + if (cpu_has_feature(CPU_FTR_ALTIVEC)) + current->thread.vrsave = mfspr(SPRN_VRSAVE); +#endif +#ifdef CONFIG_VSX + if (current->thread.used_vsr && ctx_has_vsx_region) + flush_vsx_to_thread(current); +#endif +#ifdef CONFIG_SPE + if (current->thread.used_spe) + flush_spe_to_thread(current); +#endif +} + +static __always_inline int +__unsafe_save_user_regs(struct pt_regs *regs, struct mcontext __user *frame, + struct mcontext __user *tm_frame, int ctx_has_vsx_region) +{ + unsigned long msr = regs->msr; + + /* save general registers */ + unsafe_save_general_regs(regs, frame, failed); + +#ifdef CONFIG_ALTIVEC + /* save altivec registers */ + if (current->thread.used_vr) { + unsafe_copy_to_user(&frame->mc_vregs, ¤t->thread.vr_state, + ELF_NVRREG * sizeof(vector128), failed); + /* set MSR_VEC in the saved MSR value to indicate that + frame->mc_vregs contains valid data */ + msr |= MSR_VEC; + } + /* 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 + * Note that the current VRSAVE value is in the SPR at this point. + */ + unsafe_put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32], + failed); +#endif /* CONFIG_ALTIVEC */ + unsafe_copy_fpr_to_user(&frame->mc_fregs, current, failed); + + /* + * 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 VSR 0-31 upper half from thread_struct to local + * buffer, then write that to userspace. Also set MSR_VSX in + * the saved MSR value to indicate that frame->mc_vregs + * contains valid data + */ + if (current->thread.used_vsr && ctx_has_vsx_region) { + unsafe_copy_vsx_to_user(&frame->mc_vsregs, current, failed); + msr |= MSR_VSX; + } +#endif /* CONFIG_VSX */ +#ifdef CONFIG_SPE + /* save spe registers */ + if (current->thread.used_spe) { + unsafe_copy_to_user(&frame->mc_vregs, current->thread.evr, + ELF_NEVRREG * sizeof(u32), failed); + /* set MSR_SPE in the saved MSR value to indicate that + frame->mc_vregs contains valid data */ + msr |= MSR_SPE; + } + /* else assert((regs->msr & MSR_SPE) == 0) */ + + /* We always copy to/from spefscr */ + unsafe_put_user(current->thread.spefscr, + (u32 __user *)&frame->mc_vregs + ELF_NEVRREG, failed); +#endif /* CONFIG_SPE */ + + unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed); + + /* We need to write 0 the MSR top 32 bits in the tm frame so that we + * can check it on the restore to see if TM is active + */ + if (tm_frame) + unsafe_put_user(0, &tm_frame->mc_gregs[PT_MSR], failed); + + return 0; + +failed: + return 1; +} + +#define unsafe_save_user_regs(regs, frame, tm_frame, has_vsx, label) do { \ + if (__unsafe_save_user_regs(regs, frame, tm_frame, has_vsx)) \ + goto label; \ +} while (0) + +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM +/* + * Save the current user registers on the user stack. + * We only save the altivec/spe registers if the process has used + * altivec/spe instructions at some point. + * We also save the transactional registers to a second ucontext in the + * frame. + * + * See __unsafe_save_user_regs() and signal_64.c:setup_tm_sigcontexts(). + */ +static void prepare_save_tm_user_regs(void) +{ + WARN_ON(tm_suspend_disabled); + + if (cpu_has_feature(CPU_FTR_ALTIVEC)) + current->thread.ckvrsave = mfspr(SPRN_VRSAVE); +} + +static __always_inline int +save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame, + struct mcontext __user *tm_frame, unsigned long msr) +{ + /* Save both sets of general registers */ + unsafe_save_general_regs(¤t->thread.ckpt_regs, frame, failed); + unsafe_save_general_regs(regs, tm_frame, failed); + + /* Stash the top half of the 64bit MSR into the 32bit MSR word + * of the transactional mcontext. This way we have a backward-compatible + * MSR in the 'normal' (checkpointed) mcontext and additionally one can + * also look at what type of transaction (T or S) was active at the + * time of the signal. + */ + unsafe_put_user((msr >> 32), &tm_frame->mc_gregs[PT_MSR], failed); + + /* save altivec registers */ + if (current->thread.used_vr) { + unsafe_copy_to_user(&frame->mc_vregs, ¤t->thread.ckvr_state, + ELF_NVRREG * sizeof(vector128), failed); + if (msr & MSR_VEC) + unsafe_copy_to_user(&tm_frame->mc_vregs, + ¤t->thread.vr_state, + ELF_NVRREG * sizeof(vector128), failed); + else + unsafe_copy_to_user(&tm_frame->mc_vregs, + ¤t->thread.ckvr_state, + ELF_NVRREG * sizeof(vector128), failed); + + /* set MSR_VEC in the saved MSR value to indicate that + * frame->mc_vregs 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. 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 + */ + unsafe_put_user(current->thread.ckvrsave, + (u32 __user *)&frame->mc_vregs[32], failed); + if (msr & MSR_VEC) + unsafe_put_user(current->thread.vrsave, + (u32 __user *)&tm_frame->mc_vregs[32], failed); + else + unsafe_put_user(current->thread.ckvrsave, + (u32 __user *)&tm_frame->mc_vregs[32], failed); + + unsafe_copy_ckfpr_to_user(&frame->mc_fregs, current, failed); + if (msr & MSR_FP) + unsafe_copy_fpr_to_user(&tm_frame->mc_fregs, current, failed); + else + unsafe_copy_ckfpr_to_user(&tm_frame->mc_fregs, current, failed); + + /* + * Copy VSR 0-31 upper half from thread_struct to local + * buffer, then write that to userspace. Also set MSR_VSX in + * the saved MSR value to indicate that frame->mc_vregs + * contains valid data + */ + if (current->thread.used_vsr) { + unsafe_copy_ckvsx_to_user(&frame->mc_vsregs, current, failed); + if (msr & MSR_VSX) + unsafe_copy_vsx_to_user(&tm_frame->mc_vsregs, current, failed); + else + unsafe_copy_ckvsx_to_user(&tm_frame->mc_vsregs, current, failed); + + msr |= MSR_VSX; + } + + unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed); + + return 0; + +failed: + return 1; +} +#else +static void prepare_save_tm_user_regs(void) { } + +static __always_inline int +save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame, + struct mcontext __user *tm_frame, unsigned long msr) +{ + return 0; +} +#endif + +#define unsafe_save_tm_user_regs(regs, frame, tm_frame, msr, label) do { \ + if (save_tm_user_regs_unsafe(regs, frame, tm_frame, msr)) \ + goto label; \ +} while (0) + +/* + * Restore the current user register values from the user stack, + * (except for MSR). + */ +static long restore_user_regs(struct pt_regs *regs, + struct mcontext __user *sr, int sig) +{ + unsigned int save_r2 = 0; + unsigned long msr; +#ifdef CONFIG_VSX + int i; +#endif + + if (!user_read_access_begin(sr, sizeof(*sr))) + return 1; + /* + * 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]; + unsafe_restore_general_regs(regs, sr, failed); + set_trap_norestart(regs); + unsafe_get_user(msr, &sr->mc_gregs[PT_MSR], failed); + if (!sig) + regs->gpr[2] = (unsigned long) save_r2; + + /* if doing signal return, restore the previous little-endian mode */ + if (sig) + regs_set_return_msr(regs, (regs->msr & ~MSR_LE) | (msr & MSR_LE)); + +#ifdef CONFIG_ALTIVEC + /* + * Force the process to reload the altivec registers from + * current->thread when it next does altivec instructions + */ + regs_set_return_msr(regs, regs->msr & ~MSR_VEC); + if (msr & MSR_VEC) { + /* restore altivec registers from the stack */ + unsafe_copy_from_user(¤t->thread.vr_state, &sr->mc_vregs, + sizeof(sr->mc_vregs), failed); + current->thread.used_vr = true; + } else if (current->thread.used_vr) + memset(¤t->thread.vr_state, 0, + ELF_NVRREG * sizeof(vector128)); + + /* Always get VRSAVE back */ + unsafe_get_user(current->thread.vrsave, (u32 __user *)&sr->mc_vregs[32], failed); + if (cpu_has_feature(CPU_FTR_ALTIVEC)) + mtspr(SPRN_VRSAVE, current->thread.vrsave); +#endif /* CONFIG_ALTIVEC */ + unsafe_copy_fpr_from_user(current, &sr->mc_fregs, failed); + +#ifdef CONFIG_VSX + /* + * Force the process to reload the VSX registers from + * current->thread when it next does VSX instruction. + */ + regs_set_return_msr(regs, regs->msr & ~MSR_VSX); + if (msr & MSR_VSX) { + /* + * Restore altivec registers from the stack to a local + * buffer, then write this out to the thread_struct + */ + unsafe_copy_vsx_from_user(current, &sr->mc_vsregs, failed); + current->thread.used_vsr = true; + } else if (current->thread.used_vsr) + for (i = 0; i < 32 ; i++) + current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; +#endif /* CONFIG_VSX */ + /* + * force the process to reload the FP registers from + * current->thread when it next does FP instructions + */ + regs_set_return_msr(regs, regs->msr & ~(MSR_FP | MSR_FE0 | MSR_FE1)); + +#ifdef CONFIG_SPE + /* + * Force the process to reload the spe registers from + * current->thread when it next does spe instructions. + * Since this is user ABI, we must enforce the sizing. + */ + BUILD_BUG_ON(sizeof(current->thread.spe) != ELF_NEVRREG * sizeof(u32)); + regs_set_return_msr(regs, regs->msr & ~MSR_SPE); + if (msr & MSR_SPE) { + /* restore spe registers from the stack */ + unsafe_copy_from_user(¤t->thread.spe, &sr->mc_vregs, + sizeof(current->thread.spe), failed); + current->thread.used_spe = true; + } else if (current->thread.used_spe) + memset(¤t->thread.spe, 0, sizeof(current->thread.spe)); + + /* Always get SPEFSCR back */ + unsafe_get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs + ELF_NEVRREG, failed); +#endif /* CONFIG_SPE */ + + user_read_access_end(); + return 0; + +failed: + user_read_access_end(); + return 1; +} + +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM +/* + * Restore the current user register values from the user stack, except for + * MSR, and recheckpoint the original checkpointed register state for processes + * in transactions. + */ +static long restore_tm_user_regs(struct pt_regs *regs, + struct mcontext __user *sr, + struct mcontext __user *tm_sr) +{ + unsigned long msr, msr_hi; + int i; + + if (tm_suspend_disabled) + return 1; + /* + * restore general registers but not including MSR or SOFTE. Also + * take care of keeping r2 (TLS) intact if not a signal. + * See comment in signal_64.c:restore_tm_sigcontexts(); + * TFHAR is restored from the checkpointed NIP; TEXASR and TFIAR + * were set by the signal delivery. + */ + if (!user_read_access_begin(sr, sizeof(*sr))) + return 1; + + unsafe_restore_general_regs(¤t->thread.ckpt_regs, sr, failed); + unsafe_get_user(current->thread.tm_tfhar, &sr->mc_gregs[PT_NIP], failed); + unsafe_get_user(msr, &sr->mc_gregs[PT_MSR], failed); + + /* Restore the previous little-endian mode */ + regs_set_return_msr(regs, (regs->msr & ~MSR_LE) | (msr & MSR_LE)); + + regs_set_return_msr(regs, regs->msr & ~MSR_VEC); + if (msr & MSR_VEC) { + /* restore altivec registers from the stack */ + unsafe_copy_from_user(¤t->thread.ckvr_state, &sr->mc_vregs, + sizeof(sr->mc_vregs), failed); + current->thread.used_vr = true; + } else if (current->thread.used_vr) { + memset(¤t->thread.vr_state, 0, + ELF_NVRREG * sizeof(vector128)); + memset(¤t->thread.ckvr_state, 0, + ELF_NVRREG * sizeof(vector128)); + } + + /* Always get VRSAVE back */ + unsafe_get_user(current->thread.ckvrsave, + (u32 __user *)&sr->mc_vregs[32], failed); + if (cpu_has_feature(CPU_FTR_ALTIVEC)) + mtspr(SPRN_VRSAVE, current->thread.ckvrsave); + + regs_set_return_msr(regs, regs->msr & ~(MSR_FP | MSR_FE0 | MSR_FE1)); + + unsafe_copy_fpr_from_user(current, &sr->mc_fregs, failed); + + regs_set_return_msr(regs, regs->msr & ~MSR_VSX); + if (msr & MSR_VSX) { + /* + * Restore altivec registers from the stack to a local + * buffer, then write this out to the thread_struct + */ + unsafe_copy_ckvsx_from_user(current, &sr->mc_vsregs, failed); + current->thread.used_vsr = true; + } else if (current->thread.used_vsr) + for (i = 0; i < 32 ; i++) { + current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; + current->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0; + } + + user_read_access_end(); + + if (!user_read_access_begin(tm_sr, sizeof(*tm_sr))) + return 1; + + unsafe_restore_general_regs(regs, tm_sr, failed); + + /* restore altivec registers from the stack */ + if (msr & MSR_VEC) + unsafe_copy_from_user(¤t->thread.vr_state, &tm_sr->mc_vregs, + sizeof(sr->mc_vregs), failed); + + /* Always get VRSAVE back */ + unsafe_get_user(current->thread.vrsave, + (u32 __user *)&tm_sr->mc_vregs[32], failed); + + unsafe_copy_ckfpr_from_user(current, &tm_sr->mc_fregs, failed); + + if (msr & MSR_VSX) { + /* + * Restore altivec registers from the stack to a local + * buffer, then write this out to the thread_struct + */ + unsafe_copy_vsx_from_user(current, &tm_sr->mc_vsregs, failed); + current->thread.used_vsr = true; + } + + /* Get the top half of the MSR from the user context */ + unsafe_get_user(msr_hi, &tm_sr->mc_gregs[PT_MSR], failed); + msr_hi <<= 32; + + user_read_access_end(); + + /* If TM bits are set to the reserved value, it's an invalid context */ + if (MSR_TM_RESV(msr_hi)) + return 1; + + /* + * Disabling preemption, since it is unsafe to be preempted + * with MSR[TS] set without recheckpointing. + */ + preempt_disable(); + + /* + * 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. + * + * Pull in the MSR TM bits from the user context + */ + regs_set_return_msr(regs, (regs->msr & ~MSR_TS_MASK) | (msr_hi & MSR_TS_MASK)); + /* Now, recheckpoint. This loads up all of the checkpointed (older) + * registers, including FP and V[S]Rs. After recheckpointing, the + * transactional versions should be loaded. + */ + 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); + + /* This loads the speculative FP/VEC state, if used */ + msr_check_and_set(msr & (MSR_FP | MSR_VEC)); + if (msr & MSR_FP) { + load_fp_state(¤t->thread.fp_state); + regs_set_return_msr(regs, regs->msr | (MSR_FP | current->thread.fpexc_mode)); + } + if (msr & MSR_VEC) { + load_vr_state(¤t->thread.vr_state); + regs_set_return_msr(regs, regs->msr | MSR_VEC); + } + + preempt_enable(); + + return 0; + +failed: + user_read_access_end(); + return 1; +} +#else +static long restore_tm_user_regs(struct pt_regs *regs, struct mcontext __user *sr, + struct mcontext __user *tm_sr) +{ + return 0; +} +#endif + +#ifdef CONFIG_PPC64 + +#define copy_siginfo_to_user copy_siginfo_to_user32 + +#endif /* CONFIG_PPC64 */ + +/* + * Set up a signal frame for a "real-time" signal handler + * (one which gets siginfo). + */ +int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, + struct task_struct *tsk) +{ + struct rt_sigframe __user *frame; + struct mcontext __user *mctx; + struct mcontext __user *tm_mctx = NULL; + unsigned long newsp = 0; + unsigned long tramp; + struct pt_regs *regs = tsk->thread.regs; + /* Save the thread's msr before get_tm_stackpointer() changes it */ + unsigned long msr = regs->msr; + + /* Set up Signal Frame */ + frame = get_sigframe(ksig, tsk, sizeof(*frame), 1); + mctx = &frame->uc.uc_mcontext; +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + tm_mctx = &frame->uc_transact.uc_mcontext; +#endif + if (MSR_TM_ACTIVE(msr)) + prepare_save_tm_user_regs(); + else + prepare_save_user_regs(1); + + if (!user_access_begin(frame, sizeof(*frame))) + goto badframe; + + /* Put the siginfo & fill in most of the ucontext */ + unsafe_put_user(0, &frame->uc.uc_flags, failed); +#ifdef CONFIG_PPC64 + unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->gpr[1], failed); +#else + unsafe_save_altstack(&frame->uc.uc_stack, regs->gpr[1], failed); +#endif + unsafe_put_user(to_user_ptr(&frame->uc.uc_mcontext), &frame->uc.uc_regs, failed); + + if (MSR_TM_ACTIVE(msr)) { +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + unsafe_put_user((unsigned long)&frame->uc_transact, + &frame->uc.uc_link, failed); + unsafe_put_user((unsigned long)tm_mctx, + &frame->uc_transact.uc_regs, failed); +#endif + unsafe_save_tm_user_regs(regs, mctx, tm_mctx, msr, failed); + } else { + unsafe_put_user(0, &frame->uc.uc_link, failed); + unsafe_save_user_regs(regs, mctx, tm_mctx, 1, failed); + } + + /* Save user registers on the stack */ + if (tsk->mm->context.vdso) { + tramp = VDSO32_SYMBOL(tsk->mm->context.vdso, sigtramp_rt32); + } else { + tramp = (unsigned long)mctx->mc_pad; + unsafe_put_user(PPC_RAW_LI(_R0, __NR_rt_sigreturn), &mctx->mc_pad[0], failed); + unsafe_put_user(PPC_RAW_SC(), &mctx->mc_pad[1], failed); + asm("dcbst %y0; sync; icbi %y0; sync" :: "Z" (mctx->mc_pad[0])); + } + unsafe_put_sigset_t(&frame->uc.uc_sigmask, oldset, failed); + + user_access_end(); + + if (copy_siginfo_to_user(&frame->info, &ksig->info)) + goto badframe; + + regs->link = tramp; + +#ifdef CONFIG_PPC_FPU_REGS + tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */ +#endif + + /* create a stack frame for the caller of the handler */ + newsp = ((unsigned long)frame) - (__SIGNAL_FRAMESIZE + 16); + if (put_user(regs->gpr[1], (u32 __user *)newsp)) + goto badframe; + + /* Fill registers for signal handler */ + regs->gpr[1] = newsp; + regs->gpr[3] = ksig->sig; + regs->gpr[4] = (unsigned long)&frame->info; + regs->gpr[5] = (unsigned long)&frame->uc; + regs->gpr[6] = (unsigned long)frame; + regs_set_return_ip(regs, (unsigned long) ksig->ka.sa.sa_handler); + /* enter the signal handler in native-endian mode */ + regs_set_return_msr(regs, (regs->msr & ~MSR_LE) | (MSR_KERNEL & MSR_LE)); + + return 0; + +failed: + user_access_end(); + +badframe: + signal_fault(tsk, regs, "handle_rt_signal32", frame); + + return 1; +} + +/* + * OK, we're invoking a handler + */ +int handle_signal32(struct ksignal *ksig, sigset_t *oldset, + struct task_struct *tsk) +{ + struct sigcontext __user *sc; + struct sigframe __user *frame; + struct mcontext __user *mctx; + struct mcontext __user *tm_mctx = NULL; + unsigned long newsp = 0; + unsigned long tramp; + struct pt_regs *regs = tsk->thread.regs; + /* Save the thread's msr before get_tm_stackpointer() changes it */ + unsigned long msr = regs->msr; + + /* Set up Signal Frame */ + frame = get_sigframe(ksig, tsk, sizeof(*frame), 1); + mctx = &frame->mctx; +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + tm_mctx = &frame->mctx_transact; +#endif + if (MSR_TM_ACTIVE(msr)) + prepare_save_tm_user_regs(); + else + prepare_save_user_regs(1); + + if (!user_access_begin(frame, sizeof(*frame))) + goto badframe; + sc = (struct sigcontext __user *) &frame->sctx; + +#if _NSIG != 64 +#error "Please adjust handle_signal()" +#endif + unsafe_put_user(to_user_ptr(ksig->ka.sa.sa_handler), &sc->handler, failed); + unsafe_put_user(oldset->sig[0], &sc->oldmask, failed); +#ifdef CONFIG_PPC64 + unsafe_put_user((oldset->sig[0] >> 32), &sc->_unused[3], failed); +#else + unsafe_put_user(oldset->sig[1], &sc->_unused[3], failed); +#endif + unsafe_put_user(to_user_ptr(mctx), &sc->regs, failed); + unsafe_put_user(ksig->sig, &sc->signal, failed); + + if (MSR_TM_ACTIVE(msr)) + unsafe_save_tm_user_regs(regs, mctx, tm_mctx, msr, failed); + else + unsafe_save_user_regs(regs, mctx, tm_mctx, 1, failed); + + if (tsk->mm->context.vdso) { + tramp = VDSO32_SYMBOL(tsk->mm->context.vdso, sigtramp32); + } else { + tramp = (unsigned long)mctx->mc_pad; + unsafe_put_user(PPC_RAW_LI(_R0, __NR_sigreturn), &mctx->mc_pad[0], failed); + unsafe_put_user(PPC_RAW_SC(), &mctx->mc_pad[1], failed); + asm("dcbst %y0; sync; icbi %y0; sync" :: "Z" (mctx->mc_pad[0])); + } + user_access_end(); + + regs->link = tramp; + +#ifdef CONFIG_PPC_FPU_REGS + tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */ +#endif + + /* create a stack frame for the caller of the handler */ + newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE; + if (put_user(regs->gpr[1], (u32 __user *)newsp)) + goto badframe; + + regs->gpr[1] = newsp; + regs->gpr[3] = ksig->sig; + regs->gpr[4] = (unsigned long) sc; + regs_set_return_ip(regs, (unsigned long) ksig->ka.sa.sa_handler); + /* enter the signal handler in native-endian mode */ + regs_set_return_msr(regs, (regs->msr & ~MSR_LE) | (MSR_KERNEL & MSR_LE)); + + return 0; + +failed: + user_access_end(); + +badframe: + signal_fault(tsk, regs, "handle_signal32", frame); + + return 1; +} + +static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int sig) +{ + sigset_t set; + struct mcontext __user *mcp; + + if (!user_read_access_begin(ucp, sizeof(*ucp))) + return -EFAULT; + + unsafe_get_sigset_t(&set, &ucp->uc_sigmask, failed); +#ifdef CONFIG_PPC64 + { + u32 cmcp; + + unsafe_get_user(cmcp, &ucp->uc_regs, failed); + mcp = (struct mcontext __user *)(u64)cmcp; + } +#else + unsafe_get_user(mcp, &ucp->uc_regs, failed); +#endif + user_read_access_end(); + + set_current_blocked(&set); + if (restore_user_regs(regs, mcp, sig)) + return -EFAULT; + + return 0; + +failed: + user_read_access_end(); + return -EFAULT; +} + +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM +static int do_setcontext_tm(struct ucontext __user *ucp, + struct ucontext __user *tm_ucp, + struct pt_regs *regs) +{ + sigset_t set; + struct mcontext __user *mcp; + struct mcontext __user *tm_mcp; + u32 cmcp; + u32 tm_cmcp; + + if (!user_read_access_begin(ucp, sizeof(*ucp))) + return -EFAULT; + + unsafe_get_sigset_t(&set, &ucp->uc_sigmask, failed); + unsafe_get_user(cmcp, &ucp->uc_regs, failed); + + user_read_access_end(); + + if (__get_user(tm_cmcp, &tm_ucp->uc_regs)) + return -EFAULT; + mcp = (struct mcontext __user *)(u64)cmcp; + tm_mcp = (struct mcontext __user *)(u64)tm_cmcp; + /* no need to check access_ok(mcp), since mcp < 4GB */ + + set_current_blocked(&set); + if (restore_tm_user_regs(regs, mcp, tm_mcp)) + return -EFAULT; + + return 0; + +failed: + user_read_access_end(); + return -EFAULT; +} +#endif + +#ifdef CONFIG_PPC64 +COMPAT_SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, + struct ucontext __user *, new_ctx, int, ctx_size) +#else +SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, + struct ucontext __user *, new_ctx, long, ctx_size) +#endif +{ + struct pt_regs *regs = current_pt_regs(); + int ctx_has_vsx_region = 0; + +#ifdef CONFIG_PPC64 + unsigned long new_msr = 0; + + if (new_ctx) { + struct mcontext __user *mcp; + u32 cmcp; + + /* + * Get pointer to the real mcontext. No need for + * access_ok since we are dealing with compat + * pointers. + */ + if (__get_user(cmcp, &new_ctx->uc_regs)) + return -EFAULT; + mcp = (struct mcontext __user *)(u64)cmcp; + if (__get_user(new_msr, &mcp->mc_gregs[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; +#else + /* Context size is for future use. Right now, we only make sure + * we are passed something we understand + */ + if (ctx_size < sizeof(struct ucontext)) + return -EINVAL; +#endif + if (old_ctx != NULL) { + struct mcontext __user *mctx; + + /* + * old_ctx might not be 16-byte aligned, in which + * case old_ctx->uc_mcontext won't be either. + * Because we have the old_ctx->uc_pad2 field + * before old_ctx->uc_mcontext, we need to round down + * from &old_ctx->uc_mcontext to a 16-byte boundary. + */ + mctx = (struct mcontext __user *) + ((unsigned long) &old_ctx->uc_mcontext & ~0xfUL); + prepare_save_user_regs(ctx_has_vsx_region); + if (!user_write_access_begin(old_ctx, ctx_size)) + return -EFAULT; + unsafe_save_user_regs(regs, mctx, NULL, ctx_has_vsx_region, failed); + unsafe_put_sigset_t(&old_ctx->uc_sigmask, ¤t->blocked, failed); + unsafe_put_user(to_user_ptr(mctx), &old_ctx->uc_regs, failed); + user_write_access_end(); + } + if (new_ctx == NULL) + return 0; + if (!access_ok(new_ctx, ctx_size) || + fault_in_readable((char __user *)new_ctx, ctx_size)) + 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_setcontext(new_ctx, regs, 0)) { + force_exit_sig(SIGSEGV); + return -EFAULT; + } + + set_thread_flag(TIF_RESTOREALL); + return 0; + +failed: + user_write_access_end(); + return -EFAULT; +} + +#ifdef CONFIG_PPC64 +COMPAT_SYSCALL_DEFINE0(rt_sigreturn) +#else +SYSCALL_DEFINE0(rt_sigreturn) +#endif +{ + struct rt_sigframe __user *rt_sf; + struct pt_regs *regs = current_pt_regs(); + int tm_restore = 0; +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + struct ucontext __user *uc_transact; + unsigned long msr_hi; + unsigned long tmp; +#endif + /* Always make any pending restarted system calls return -EINTR */ + current->restart_block.fn = do_no_restart_syscall; + + rt_sf = (struct rt_sigframe __user *) + (regs->gpr[1] + __SIGNAL_FRAMESIZE + 16); + if (!access_ok(rt_sf, sizeof(*rt_sf))) + goto bad; + +#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(tmp, &rt_sf->uc.uc_link)) + goto bad; + uc_transact = (struct ucontext __user *)(uintptr_t)tmp; + if (uc_transact) { + u32 cmcp; + struct mcontext __user *mcp; + + if (__get_user(cmcp, &uc_transact->uc_regs)) + return -EFAULT; + mcp = (struct mcontext __user *)(u64)cmcp; + /* The top 32 bits of the MSR are stashed in the transactional + * ucontext. */ + if (__get_user(msr_hi, &mcp->mc_gregs[PT_MSR])) + goto bad; + + if (MSR_TM_ACTIVE(msr_hi<<32)) { + /* Trying to start TM on non TM system */ + if (!cpu_has_feature(CPU_FTR_TM)) + goto bad; + /* We only recheckpoint on return if we're + * transaction. + */ + tm_restore = 1; + if (do_setcontext_tm(&rt_sf->uc, uc_transact, regs)) + goto bad; + } + } + if (!tm_restore) { + /* + * Unset regs->msr because ucontext MSR TS is not + * set, and recheckpoint was not called. This avoid + * hitting a TM Bad thing at RFID + */ + regs_set_return_msr(regs, regs->msr & ~MSR_TS_MASK); + } + /* Fall through, for non-TM restore */ +#endif + if (!tm_restore) + if (do_setcontext(&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 + */ +#ifdef CONFIG_PPC64 + if (compat_restore_altstack(&rt_sf->uc.uc_stack)) + goto bad; +#else + if (restore_altstack(&rt_sf->uc.uc_stack)) + goto bad; +#endif + set_thread_flag(TIF_RESTOREALL); + return 0; + + bad: + signal_fault(current, regs, "sys_rt_sigreturn", rt_sf); + + force_sig(SIGSEGV); + return 0; +} + +#ifdef CONFIG_PPC32 +SYSCALL_DEFINE3(debug_setcontext, struct ucontext __user *, ctx, + int, ndbg, struct sig_dbg_op __user *, dbg) +{ + struct pt_regs *regs = current_pt_regs(); + struct sig_dbg_op op; + int i; + unsigned long new_msr = regs->msr; +#ifdef CONFIG_PPC_ADV_DEBUG_REGS + unsigned long new_dbcr0 = current->thread.debug.dbcr0; +#endif + + for (i=0; i<ndbg; i++) { + if (copy_from_user(&op, dbg + i, sizeof(op))) + return -EFAULT; + switch (op.dbg_type) { + case SIG_DBG_SINGLE_STEPPING: +#ifdef CONFIG_PPC_ADV_DEBUG_REGS + if (op.dbg_value) { + new_msr |= MSR_DE; + new_dbcr0 |= (DBCR0_IDM | DBCR0_IC); + } else { + new_dbcr0 &= ~DBCR0_IC; + if (!DBCR_ACTIVE_EVENTS(new_dbcr0, + current->thread.debug.dbcr1)) { + new_msr &= ~MSR_DE; + new_dbcr0 &= ~DBCR0_IDM; + } + } +#else + if (op.dbg_value) + new_msr |= MSR_SE; + else + new_msr &= ~MSR_SE; +#endif + break; + case SIG_DBG_BRANCH_TRACING: +#ifdef CONFIG_PPC_ADV_DEBUG_REGS + return -EINVAL; +#else + if (op.dbg_value) + new_msr |= MSR_BE; + else + new_msr &= ~MSR_BE; +#endif + break; + + default: + return -EINVAL; + } + } + + /* We wait until here to actually install the values in the + registers so if we fail in the above loop, it will not + affect the contents of these registers. After this point, + failure is a problem, anyway, and it's very unlikely unless + the user is really doing something wrong. */ + regs_set_return_msr(regs, new_msr); +#ifdef CONFIG_PPC_ADV_DEBUG_REGS + current->thread.debug.dbcr0 = new_dbcr0; +#endif + + if (!access_ok(ctx, sizeof(*ctx)) || + fault_in_readable((char __user *)ctx, sizeof(*ctx))) + 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_setcontext(ctx, regs, 1)) { + signal_fault(current, regs, "sys_debug_setcontext", ctx); + + force_sig(SIGSEGV); + goto out; + } + + /* + * 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 + */ + restore_altstack(&ctx->uc_stack); + + set_thread_flag(TIF_RESTOREALL); + out: + return 0; +} +#endif + +/* + * Do a signal return; undo the signal stack. + */ +#ifdef CONFIG_PPC64 +COMPAT_SYSCALL_DEFINE0(sigreturn) +#else +SYSCALL_DEFINE0(sigreturn) +#endif +{ + struct pt_regs *regs = current_pt_regs(); + struct sigframe __user *sf; + struct sigcontext __user *sc; + struct sigcontext sigctx; + struct mcontext __user *sr; + sigset_t set; + struct mcontext __user *mcp; + struct mcontext __user *tm_mcp = NULL; + unsigned long long msr_hi = 0; + + /* Always make any pending restarted system calls return -EINTR */ + current->restart_block.fn = do_no_restart_syscall; + + sf = (struct sigframe __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE); + sc = &sf->sctx; + if (copy_from_user(&sigctx, sc, sizeof(sigctx))) + goto badframe; + +#ifdef CONFIG_PPC64 + /* + * 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); +#else + set.sig[0] = sigctx.oldmask; + set.sig[1] = sigctx._unused[3]; +#endif + set_current_blocked(&set); + + mcp = (struct mcontext __user *)&sf->mctx; +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + tm_mcp = (struct mcontext __user *)&sf->mctx_transact; + if (__get_user(msr_hi, &tm_mcp->mc_gregs[PT_MSR])) + goto badframe; +#endif + if (MSR_TM_ACTIVE(msr_hi<<32)) { + if (!cpu_has_feature(CPU_FTR_TM)) + goto badframe; + if (restore_tm_user_regs(regs, mcp, tm_mcp)) + goto badframe; + } else { + sr = (struct mcontext __user *)from_user_ptr(sigctx.regs); + if (restore_user_regs(regs, sr, 1)) { + signal_fault(current, regs, "sys_sigreturn", sr); + + force_sig(SIGSEGV); + return 0; + } + } + + set_thread_flag(TIF_RESTOREALL); + return 0; + +badframe: + signal_fault(current, regs, "sys_sigreturn", sc); + + force_sig(SIGSEGV); + return 0; +} |