From d11994314b2bfe028bc39be24b44298787925160 Mon Sep 17 00:00:00 2001 From: Cyril Bur Date: Fri, 23 Sep 2016 16:18:12 +1000 Subject: [PATCH] powerpc: signals: Stop using current in signal code Much of the signal code takes a pt_regs on which it operates. Over time the signal code has needed to know more about the thread than what pt_regs can supply, this information is obtained as needed by using 'current'. This approach is not strictly incorrect however it does mean that there is now a hard requirement that the pt_regs being passed around does belong to current, this is never checked. A safer approach is for the majority of the signal functions to take a task_struct from which they can obtain pt_regs and any other information they need. The caveat that the task_struct they are passed must be current doesn't go away but can more easily be checked for. Functions called from outside powerpc signal code are passed a pt_regs and they can confirm that the pt_regs is that of current and pass current to other functions, furthurmore, powerpc signal functions can check that the task_struct they are passed is the same as current avoiding possible corruption of current (or the task they are passed) if this assertion ever fails. CC: paulus@samba.org Signed-off-by: Cyril Bur Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/signal.h | 2 - arch/powerpc/kernel/signal.c | 41 +++--- arch/powerpc/kernel/signal.h | 10 +- arch/powerpc/kernel/signal_32.c | 31 +++-- arch/powerpc/kernel/signal_64.c | 201 +++++++++++++++++------------- 5 files changed, 159 insertions(+), 126 deletions(-) diff --git a/arch/powerpc/include/asm/signal.h b/arch/powerpc/include/asm/signal.h index 9322c28aebd2..5ff77722a52d 100644 --- a/arch/powerpc/include/asm/signal.h +++ b/arch/powerpc/include/asm/signal.h @@ -5,6 +5,4 @@ #include #include -extern unsigned long get_tm_stackpointer(struct pt_regs *regs); - #endif /* _ASM_POWERPC_SIGNAL_H */ diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c index cb64d6feb45a..bbe77aed198d 100644 --- a/arch/powerpc/kernel/signal.c +++ b/arch/powerpc/kernel/signal.c @@ -99,22 +99,24 @@ static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka, } } -static void do_signal(struct pt_regs *regs) +static void do_signal(struct task_struct *tsk) { sigset_t *oldset = sigmask_to_save(); struct ksignal ksig; int ret; int is32 = is_32bit_task(); + BUG_ON(tsk != current); + get_signal(&ksig); /* Is there any syscall restart business here ? */ - check_syscall_restart(regs, &ksig.ka, ksig.sig > 0); + check_syscall_restart(tsk->thread.regs, &ksig.ka, ksig.sig > 0); if (ksig.sig <= 0) { /* No signal to deliver -- put the saved sigmask back */ restore_saved_sigmask(); - regs->trap = 0; + tsk->thread.regs->trap = 0; return; /* no signals delivered */ } @@ -124,23 +126,22 @@ static void do_signal(struct pt_regs *regs) * user space. The DABR will have been cleared if it * triggered inside the kernel. */ - if (current->thread.hw_brk.address && - current->thread.hw_brk.type) - __set_breakpoint(¤t->thread.hw_brk); + if (tsk->thread.hw_brk.address && tsk->thread.hw_brk.type) + __set_breakpoint(&tsk->thread.hw_brk); #endif /* Re-enable the breakpoints for the signal stack */ - thread_change_pc(current, regs); + thread_change_pc(tsk, tsk->thread.regs); if (is32) { if (ksig.ka.sa.sa_flags & SA_SIGINFO) - ret = handle_rt_signal32(&ksig, oldset, regs); + ret = handle_rt_signal32(&ksig, oldset, tsk); else - ret = handle_signal32(&ksig, oldset, regs); + ret = handle_signal32(&ksig, oldset, tsk); } else { - ret = handle_rt_signal64(&ksig, oldset, regs); + ret = handle_rt_signal64(&ksig, oldset, tsk); } - regs->trap = 0; + tsk->thread.regs->trap = 0; signal_setup_done(ret, &ksig, test_thread_flag(TIF_SINGLESTEP)); } @@ -151,8 +152,10 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags) if (thread_info_flags & _TIF_UPROBE) uprobe_notify_resume(regs); - if (thread_info_flags & _TIF_SIGPENDING) - do_signal(regs); + if (thread_info_flags & _TIF_SIGPENDING) { + BUG_ON(regs != current->thread.regs); + do_signal(current); + } if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); @@ -162,7 +165,7 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags) user_enter(); } -unsigned long get_tm_stackpointer(struct pt_regs *regs) +unsigned long get_tm_stackpointer(struct task_struct *tsk) { /* When in an active transaction that takes a signal, we need to be * careful with the stack. It's possible that the stack has moved back @@ -187,11 +190,13 @@ unsigned long get_tm_stackpointer(struct pt_regs *regs) */ #ifdef CONFIG_PPC_TRANSACTIONAL_MEM - if (MSR_TM_ACTIVE(regs->msr)) { + BUG_ON(tsk != current); + + if (MSR_TM_ACTIVE(tsk->thread.regs->msr)) { tm_reclaim_current(TM_CAUSE_SIGNAL); - if (MSR_TM_TRANSACTIONAL(regs->msr)) - return current->thread.ckpt_regs.gpr[1]; + if (MSR_TM_TRANSACTIONAL(tsk->thread.regs->msr)) + return tsk->thread.ckpt_regs.gpr[1]; } #endif - return regs->gpr[1]; + return tsk->thread.regs->gpr[1]; } diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h index be305c858e51..254ca074504f 100644 --- a/arch/powerpc/kernel/signal.h +++ b/arch/powerpc/kernel/signal.h @@ -16,10 +16,10 @@ extern void __user *get_sigframe(struct ksignal *ksig, unsigned long sp, size_t frame_size, int is_32); extern int handle_signal32(struct ksignal *ksig, sigset_t *oldset, - struct pt_regs *regs); + struct task_struct *tsk); extern int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, - struct pt_regs *regs); + struct task_struct *tsk); extern unsigned long copy_fpr_to_user(void __user *to, struct task_struct *task); @@ -29,6 +29,8 @@ extern unsigned long copy_fpr_from_user(struct task_struct *task, void __user *from); extern unsigned long copy_transact_fpr_from_user(struct task_struct *task, void __user *from); +extern unsigned long get_tm_stackpointer(struct task_struct *tsk); + #ifdef CONFIG_VSX extern unsigned long copy_vsx_to_user(void __user *to, struct task_struct *task); @@ -43,12 +45,12 @@ extern unsigned long copy_transact_vsx_from_user(struct task_struct *task, #ifdef CONFIG_PPC64 extern int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, - struct pt_regs *regs); + struct task_struct *tsk); #else /* CONFIG_PPC64 */ static inline int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, - struct pt_regs *regs) + struct task_struct *tsk) { return -EFAULT; } diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index d2745375f27e..9637f8eb5204 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -978,7 +978,7 @@ int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from) * (one which gets siginfo). */ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, - struct pt_regs *regs) + struct task_struct *tsk) { struct rt_sigframe __user *rt_sf; struct mcontext __user *frame; @@ -987,10 +987,13 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, unsigned long newsp = 0; int sigret; unsigned long tramp; + struct pt_regs *regs = tsk->thread.regs; + + BUG_ON(tsk != current); /* Set up Signal Frame */ /* Put a Real Time Context onto stack */ - rt_sf = get_sigframe(ksig, get_tm_stackpointer(regs), sizeof(*rt_sf), 1); + rt_sf = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*rt_sf), 1); addr = rt_sf; if (unlikely(rt_sf == NULL)) goto badframe; @@ -1007,9 +1010,9 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, /* Save user registers on the stack */ frame = &rt_sf->uc.uc_mcontext; addr = frame; - if (vdso32_rt_sigtramp && current->mm->context.vdso_base) { + if (vdso32_rt_sigtramp && tsk->mm->context.vdso_base) { sigret = 0; - tramp = current->mm->context.vdso_base + vdso32_rt_sigtramp; + tramp = tsk->mm->context.vdso_base + vdso32_rt_sigtramp; } else { sigret = __NR_rt_sigreturn; tramp = (unsigned long) frame->tramp; @@ -1036,7 +1039,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, } regs->link = tramp; - current->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */ + tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */ /* create a stack frame for the caller of the handler */ newsp = ((unsigned long)rt_sf) - (__SIGNAL_FRAMESIZE + 16); @@ -1061,7 +1064,7 @@ badframe: printk_ratelimited(KERN_INFO "%s[%d]: bad frame in handle_rt_signal32: " "%p nip %08lx lr %08lx\n", - current->comm, current->pid, + tsk->comm, tsk->pid, addr, regs->nip, regs->link); return 1; @@ -1417,7 +1420,8 @@ int sys_debug_setcontext(struct ucontext __user *ctx, /* * OK, we're invoking a handler */ -int handle_signal32(struct ksignal *ksig, sigset_t *oldset, struct pt_regs *regs) +int handle_signal32(struct ksignal *ksig, sigset_t *oldset, + struct task_struct *tsk) { struct sigcontext __user *sc; struct sigframe __user *frame; @@ -1425,9 +1429,12 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, struct pt_regs *regs unsigned long newsp = 0; int sigret; unsigned long tramp; + struct pt_regs *regs = tsk->thread.regs; + + BUG_ON(tsk != current); /* Set up Signal Frame */ - frame = get_sigframe(ksig, get_tm_stackpointer(regs), sizeof(*frame), 1); + frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 1); if (unlikely(frame == NULL)) goto badframe; sc = (struct sigcontext __user *) &frame->sctx; @@ -1446,9 +1453,9 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, struct pt_regs *regs || __put_user(ksig->sig, &sc->signal)) goto badframe; - if (vdso32_sigtramp && current->mm->context.vdso_base) { + if (vdso32_sigtramp && tsk->mm->context.vdso_base) { sigret = 0; - tramp = current->mm->context.vdso_base + vdso32_sigtramp; + tramp = tsk->mm->context.vdso_base + vdso32_sigtramp; } else { sigret = __NR_sigreturn; tramp = (unsigned long) frame->mctx.tramp; @@ -1470,7 +1477,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, struct pt_regs *regs regs->link = tramp; - current->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */ + tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */ /* create a stack frame for the caller of the handler */ newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE; @@ -1490,7 +1497,7 @@ badframe: printk_ratelimited(KERN_INFO "%s[%d]: bad frame in handle_signal32: " "%p nip %08lx lr %08lx\n", - current->comm, current->pid, + tsk->comm, tsk->pid, frame, regs->nip, regs->link); return 1; diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index 6faa8240b7c9..befa10af0c17 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -91,9 +91,9 @@ static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc) * 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) +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 @@ -107,17 +107,20 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, 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 (current->thread.used_vr) { - flush_altivec_to_thread(current); + 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, ¤t->thread.vr_state, + 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. @@ -130,16 +133,16 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, vrsave = 0; if (cpu_has_feature(CPU_FTR_ALTIVEC)) { vrsave = mfspr(SPRN_VRSAVE); - current->thread.vrsave = 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(current); + flush_fp_to_thread(tsk); /* copy fpr regs and fpscr */ - err |= copy_fpr_to_user(&sc->fp_regs, current); + err |= copy_fpr_to_user(&sc->fp_regs, tsk); /* * Clear the MSR VSX bit to indicate there is no valid state attached @@ -152,10 +155,10 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, * then out to userspace. Update v_regs to point after the * VMX data. */ - if (current->thread.used_vsr && ctx_has_vsx_region) { - flush_vsx_to_thread(current); + 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, current); + 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. */ @@ -188,7 +191,7 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, */ static long setup_tm_sigcontexts(struct sigcontext __user *sc, struct sigcontext __user *tm_sc, - struct pt_regs *regs, + 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 @@ -203,9 +206,12 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc, elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc); elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc); #endif - unsigned long msr = regs->msr; + 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 @@ -215,28 +221,28 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc, */ regs->msr &= ~MSR_TS_MASK; - flush_fp_to_thread(current); + flush_fp_to_thread(tsk); #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); + 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, ¤t->thread.vr_state, + err |= __copy_to_user(v_regs, &tsk->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, + &tsk->thread.transact_vr, 33 * sizeof(vector128)); else err |= __copy_to_user(tm_v_regs, - ¤t->thread.vr_state, + &tsk->thread.vr_state, 33 * sizeof(vector128)); /* set MSR_VEC in the MSR value in the frame to indicate @@ -248,13 +254,13 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc, * 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]); + tsk->thread.vrsave = mfspr(SPRN_VRSAVE); + err |= __put_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]); if (msr & MSR_VEC) - err |= __put_user(current->thread.transact_vrsave, + err |= __put_user(tsk->thread.transact_vrsave, (u32 __user *)&tm_v_regs[33]); else - err |= __put_user(current->thread.vrsave, + err |= __put_user(tsk->thread.vrsave, (u32 __user *)&tm_v_regs[33]); #else /* CONFIG_ALTIVEC */ @@ -263,11 +269,11 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc, #endif /* CONFIG_ALTIVEC */ /* copy fpr regs and fpscr */ - err |= copy_fpr_to_user(&sc->fp_regs, current); + err |= copy_fpr_to_user(&sc->fp_regs, tsk); if (msr & MSR_FP) - err |= copy_transact_fpr_to_user(&tm_sc->fp_regs, current); + err |= copy_transact_fpr_to_user(&tm_sc->fp_regs, tsk); else - err |= copy_fpr_to_user(&tm_sc->fp_regs, current); + err |= copy_fpr_to_user(&tm_sc->fp_regs, tsk); #ifdef CONFIG_VSX /* @@ -275,17 +281,17 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc, * then out to userspace. Update v_regs to point after the * VMX data. */ - if (current->thread.used_vsr) { - flush_vsx_to_thread(current); + if (tsk->thread.used_vsr) { + flush_vsx_to_thread(tsk); v_regs += ELF_NVRREG; tm_v_regs += ELF_NVRREG; - err |= copy_vsx_to_user(v_regs, current); + err |= copy_vsx_to_user(v_regs, tsk); if (msr & MSR_VSX) - err |= copy_transact_vsx_to_user(tm_v_regs, current); + err |= copy_transact_vsx_to_user(tm_v_regs, tsk); else - err |= copy_vsx_to_user(tm_v_regs, current); + err |= copy_vsx_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. @@ -299,7 +305,7 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc, 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); + &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); @@ -315,7 +321,7 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc, * Restore the sigcontext from the signal frame. */ -static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig, +static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig, struct sigcontext __user *sc) { #ifdef CONFIG_ALTIVEC @@ -324,10 +330,13 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig, 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]; @@ -357,7 +366,7 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig, /* * Force reload of FP/VEC. - * This has to be done before copying stuff into current->thread.fpr/vr + * 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); @@ -370,22 +379,22 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig, 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, + err |= __copy_from_user(&tsk->thread.vr_state, v_regs, 33 * sizeof(vector128)); - current->thread.used_vr = true; + tsk->thread.used_vr = true; + } else if (tsk->thread.used_vr) { + memset(&tsk->thread.vr_state, 0, 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]); + err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]); else - current->thread.vrsave = 0; + tsk->thread.vrsave = 0; if (cpu_has_feature(CPU_FTR_ALTIVEC)) - mtspr(SPRN_VRSAVE, current->thread.vrsave); + mtspr(SPRN_VRSAVE, tsk->thread.vrsave); #endif /* CONFIG_ALTIVEC */ /* restore floating point */ - err |= copy_fpr_from_user(current, &sc->fp_regs); + err |= copy_fpr_from_user(tsk, &sc->fp_regs); #ifdef CONFIG_VSX /* * Get additional VSX data. Update v_regs to point after the @@ -394,11 +403,12 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig, */ v_regs += ELF_NVRREG; if ((msr & MSR_VSX) != 0) { - err |= copy_vsx_from_user(current, v_regs); - current->thread.used_vsr = true; - } else + err |= copy_vsx_from_user(tsk, v_regs); + tsk->thread.used_vsr = true; + } else { for (i = 0; i < 32 ; i++) - current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; + tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; + } #endif return err; } @@ -408,7 +418,7 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig, * Restore the two sigcontexts from the frame of a transactional processes. */ -static long restore_tm_sigcontexts(struct pt_regs *regs, +static long restore_tm_sigcontexts(struct task_struct *tsk, struct sigcontext __user *sc, struct sigcontext __user *tm_sc) { @@ -417,12 +427,16 @@ static long restore_tm_sigcontexts(struct pt_regs *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(¤t->thread.ckpt_regs, sc->gp_regs, + err |= __copy_from_user(&tsk->thread.ckpt_regs, sc->gp_regs, sizeof(regs->gpr)); /* @@ -434,7 +448,7 @@ static long restore_tm_sigcontexts(struct pt_regs *regs, * 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]); + 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]); @@ -453,13 +467,13 @@ static long restore_tm_sigcontexts(struct pt_regs *regs, 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, + err |= __get_user(tsk->thread.ckpt_regs.ctr, &sc->gp_regs[PT_CTR]); - err |= __get_user(current->thread.ckpt_regs.link, + err |= __get_user(tsk->thread.ckpt_regs.link, &sc->gp_regs[PT_LNK]); - err |= __get_user(current->thread.ckpt_regs.xer, + err |= __get_user(tsk->thread.ckpt_regs.xer, &sc->gp_regs[PT_XER]); - err |= __get_user(current->thread.ckpt_regs.ccr, + err |= __get_user(tsk->thread.ckpt_regs.ccr, &sc->gp_regs[PT_CCR]); /* These regs are not checkpointed; they can go in 'regs'. */ @@ -470,7 +484,7 @@ static long restore_tm_sigcontexts(struct pt_regs *regs, /* * Force reload of FP/VEC. - * This has to be done before copying stuff into current->thread.fpr/vr + * 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); @@ -487,33 +501,33 @@ static long restore_tm_sigcontexts(struct pt_regs *regs, 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, + err |= __copy_from_user(&tsk->thread.vr_state, v_regs, 33 * sizeof(vector128)); - err |= __copy_from_user(¤t->thread.transact_vr, tm_v_regs, + err |= __copy_from_user(&tsk->thread.transact_vr, tm_v_regs, 33 * sizeof(vector128)); current->thread.used_vr = true; } - else if (current->thread.used_vr) { - memset(¤t->thread.vr_state, 0, 33 * sizeof(vector128)); - memset(¤t->thread.transact_vr, 0, 33 * sizeof(vector128)); + else if (tsk->thread.used_vr) { + memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128)); + memset(&tsk->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, + err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]); - err |= __get_user(current->thread.transact_vrsave, + err |= __get_user(tsk->thread.transact_vrsave, (u32 __user *)&tm_v_regs[33]); } else { - current->thread.vrsave = 0; - current->thread.transact_vrsave = 0; + tsk->thread.vrsave = 0; + tsk->thread.transact_vrsave = 0; } if (cpu_has_feature(CPU_FTR_ALTIVEC)) - mtspr(SPRN_VRSAVE, current->thread.vrsave); + mtspr(SPRN_VRSAVE, tsk->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); + err |= copy_fpr_from_user(tsk, &sc->fp_regs); + err |= copy_transact_fpr_from_user(tsk, &tm_sc->fp_regs); #ifdef CONFIG_VSX /* * Get additional VSX data. Update v_regs to point after the @@ -523,30 +537,30 @@ static long restore_tm_sigcontexts(struct pt_regs *regs, 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); - current->thread.used_vsr = true; + err |= copy_vsx_from_user(tsk, v_regs); + err |= copy_transact_vsx_from_user(tsk, tm_v_regs); + tsk->thread.used_vsr = true; } 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; + tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; + tsk->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; + tsk->thread.tm_texasr |= TEXASR_FS; /* This loads the checkpointed FP/VEC state, if used */ - tm_recheckpoint(¤t->thread, msr); + tm_recheckpoint(&tsk->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); + do_load_up_transact_fpu(&tsk->thread); + regs->msr |= (MSR_FP | tsk->thread.fpexc_mode); } #ifdef CONFIG_ALTIVEC if (msr & MSR_VEC) { - do_load_up_transact_altivec(¤t->thread); + do_load_up_transact_altivec(&tsk->thread); regs->msr |= MSR_VEC; } #endif @@ -600,6 +614,8 @@ int sys_swapcontext(struct ucontext __user *old_ctx, 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; @@ -622,7 +638,7 @@ int sys_swapcontext(struct ucontext __user *old_ctx, if (old_ctx != NULL) { if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size) - || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0, + || 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))) @@ -650,7 +666,7 @@ int sys_swapcontext(struct ucontext __user *old_ctx, 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)) + if (restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext)) do_exit(SIGSEGV); /* This returns like rt_sigreturn */ @@ -673,6 +689,8 @@ int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5, 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; @@ -704,14 +722,14 @@ int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5, struct ucontext __user *uc_transact; if (__get_user(uc_transact, &uc->uc_link)) goto badframe; - if (restore_tm_sigcontexts(regs, &uc->uc_mcontext, + if (restore_tm_sigcontexts(current, &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)) + if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext)) goto badframe; if (restore_altstack(&uc->uc_stack)) @@ -730,13 +748,17 @@ badframe: return 0; } -int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) +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(regs), sizeof(*frame), 0); + frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0); if (unlikely(frame == NULL)) goto badframe; @@ -757,14 +779,13 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs 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, + 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, regs, ksig->sig, + err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig, NULL, (unsigned long)ksig->ka.sa.sa_handler, 1); } @@ -773,11 +794,11 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs goto badframe; /* Make sure signal handler doesn't get spurious FP exceptions */ - current->thread.fp_state.fpscr = 0; + tsk->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; + 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) @@ -827,7 +848,7 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs badframe: if (show_unhandled_signals) printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, - current->comm, current->pid, "setup_rt_frame", + tsk->comm, tsk->pid, "setup_rt_frame", (long)frame, regs->nip, regs->link); return 1; -- 2.20.1