diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/ia32/ia32_signal.c | 51 | ||||
| -rw-r--r-- | arch/x86/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 13 | ||||
| -rw-r--r-- | arch/x86/kernel/i387.c | 154 | ||||
| -rw-r--r-- | arch/x86/kernel/sigframe.h | 14 | ||||
| -rw-r--r-- | arch/x86/kernel/signal_32.c | 45 | ||||
| -rw-r--r-- | arch/x86/kernel/signal_64.c | 95 | ||||
| -rw-r--r-- | arch/x86/kernel/traps_32.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/traps_64.c | 6 | ||||
| -rw-r--r-- | arch/x86/kernel/xsave.c | 316 | ||||
| -rw-r--r-- | arch/x86/power/cpu_32.c | 7 | ||||
| -rw-r--r-- | arch/x86/power/cpu_64.c | 7 |
12 files changed, 545 insertions, 166 deletions
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c index 20af4c79579..f25a1012400 100644 --- a/arch/x86/ia32/ia32_signal.c +++ b/arch/x86/ia32/ia32_signal.c @@ -179,9 +179,10 @@ struct sigframe u32 pretcode; int sig; struct sigcontext_ia32 sc; - struct _fpstate_ia32 fpstate; + struct _fpstate_ia32 fpstate_unused; /* look at kernel/sigframe.h */ unsigned int extramask[_COMPAT_NSIG_WORDS-1]; char retcode[8]; + /* fp state follows here */ }; struct rt_sigframe @@ -192,8 +193,8 @@ struct rt_sigframe u32 puc; compat_siginfo_t info; struct ucontext_ia32 uc; - struct _fpstate_ia32 fpstate; char retcode[8]; + /* fp state follows here */ }; #define COPY(x) { \ @@ -215,7 +216,7 @@ static int ia32_restore_sigcontext(struct pt_regs *regs, unsigned int *peax) { unsigned int tmpflags, gs, oldgs, err = 0; - struct _fpstate_ia32 __user *buf; + void __user *buf; u32 tmp; /* Always make any pending restarted system calls return -EINTR */ @@ -259,26 +260,12 @@ static int ia32_restore_sigcontext(struct pt_regs *regs, err |= __get_user(tmp, &sc->fpstate); buf = compat_ptr(tmp); - if (buf) { - if (!access_ok(VERIFY_READ, buf, sizeof(*buf))) - goto badframe; - err |= restore_i387_ia32(buf); - } else { - struct task_struct *me = current; - - if (used_math()) { - clear_fpu(me); - clear_used_math(); - } - } + err |= restore_i387_xstate_ia32(buf); err |= __get_user(tmp, &sc->ax); *peax = tmp; return err; - -badframe: - return 1; } asmlinkage long sys32_sigreturn(struct pt_regs *regs) @@ -350,7 +337,7 @@ badframe: */ static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc, - struct _fpstate_ia32 __user *fpstate, + void __user *fpstate, struct pt_regs *regs, unsigned int mask) { int tmp, err = 0; @@ -381,7 +368,7 @@ static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc, err |= __put_user((u32)regs->flags, &sc->flags); err |= __put_user((u32)regs->sp, &sc->sp_at_signal); - tmp = save_i387_ia32(fpstate); + tmp = save_i387_xstate_ia32(fpstate); if (tmp < 0) err = -EFAULT; else { @@ -402,7 +389,8 @@ static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc, * Determine which stack to use.. */ static void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, - size_t frame_size) + size_t frame_size, + void **fpstate) { unsigned long sp; @@ -421,6 +409,11 @@ static void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, ka->sa.sa_restorer) sp = (unsigned long) ka->sa.sa_restorer; + if (used_math()) { + sp = sp - sig_xstate_ia32_size; + *fpstate = (struct _fpstate_ia32 *) sp; + } + sp -= frame_size; /* Align the stack pointer according to the i386 ABI, * i.e. so that on function entry ((sp + 4) & 15) == 0. */ @@ -434,6 +427,7 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka, struct sigframe __user *frame; void __user *restorer; int err = 0; + void __user *fpstate = NULL; /* copy_to_user optimizes that into a single 8 byte store */ static const struct { @@ -448,7 +442,7 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka, 0, }; - frame = get_sigframe(ka, regs, sizeof(*frame)); + frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; @@ -457,8 +451,7 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka, if (err) goto give_sigsegv; - err |= ia32_setup_sigcontext(&frame->sc, &frame->fpstate, regs, - set->sig[0]); + err |= ia32_setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]); if (err) goto give_sigsegv; @@ -522,6 +515,7 @@ int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, struct rt_sigframe __user *frame; void __user *restorer; int err = 0; + void __user *fpstate = NULL; /* __copy_to_user optimizes that into a single 8 byte store */ static const struct { @@ -537,7 +531,7 @@ int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 0, }; - frame = get_sigframe(ka, regs, sizeof(*frame)); + frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; @@ -550,13 +544,16 @@ int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, goto give_sigsegv; /* Create the ucontext. */ - err |= __put_user(0, &frame->uc.uc_flags); + if (cpu_has_xsave) + err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags); + else + err |= __put_user(0, &frame->uc.uc_flags); err |= __put_user(0, &frame->uc.uc_link); err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); err |= __put_user(sas_ss_flags(regs->sp), &frame->uc.uc_stack.ss_flags); err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); - err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate, + err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate, regs, set->sig[0]); err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); if (err) diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index dac24c4390d..c9be69fedb7 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -38,7 +38,7 @@ obj-y += tsc.o io_delay.o rtc.o obj-$(CONFIG_X86_TRAMPOLINE) += trampoline.o obj-y += process.o -obj-y += i387.o +obj-y += i387.o xsave.o obj-y += ptrace.o obj-y += ds.o obj-$(CONFIG_X86_32) += tls.o diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 0785b3c8d04..c63ec65f484 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -739,9 +739,20 @@ void __cpuinit cpu_init(void) /* * Force FPU initialization: */ - current_thread_info()->status = 0; + if (cpu_has_xsave) + current_thread_info()->status = TS_XSAVE; + else + current_thread_info()->status = 0; clear_used_math(); mxcsr_feature_mask_init(); + + /* + * Boot processor to setup the FP and extended state context info. + */ + if (!smp_processor_id()) + init_thread_xstate(); + + xsave_init(); } #ifdef CONFIG_HOTPLUG_CPU diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index eb9ddd8efb8..45723f1fe19 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -21,9 +21,12 @@ # include <asm/sigcontext32.h> # include <asm/user32.h> #else -# define save_i387_ia32 save_i387 -# define restore_i387_ia32 restore_i387 +# define save_i387_xstate_ia32 save_i387_xstate +# define restore_i387_xstate_ia32 restore_i387_xstate # define _fpstate_ia32 _fpstate +# define _xstate_ia32 _xstate +# define sig_xstate_ia32_size sig_xstate_size +# define fx_sw_reserved_ia32 fx_sw_reserved # define user_i387_ia32_struct user_i387_struct # define user32_fxsr_struct user_fxsr_struct #endif @@ -36,6 +39,7 @@ static unsigned int mxcsr_feature_mask __read_mostly = 0xffffffffu; unsigned int xstate_size; +unsigned int sig_xstate_ia32_size = sizeof(struct _fpstate_ia32); static struct i387_fxsave_struct fx_scratch __cpuinitdata; void __cpuinit mxcsr_feature_mask_init(void) @@ -61,6 +65,11 @@ void __init init_thread_xstate(void) return; } + if (cpu_has_xsave) { + xsave_cntxt_init(); + return; + } + if (cpu_has_fxsr) xstate_size = sizeof(struct i387_fxsave_struct); #ifdef CONFIG_X86_32 @@ -83,9 +92,19 @@ void __cpuinit fpu_init(void) write_cr0(oldcr0 & ~(X86_CR0_TS|X86_CR0_EM)); /* clear TS and EM */ + /* + * Boot processor to setup the FP and extended state context info. + */ + if (!smp_processor_id()) + init_thread_xstate(); + xsave_init(); + mxcsr_feature_mask_init(); /* clean state in init */ - current_thread_info()->status = 0; + if (cpu_has_xsave) + current_thread_info()->status = TS_XSAVE; + else + current_thread_info()->status = 0; clear_used_math(); } #endif /* CONFIG_X86_64 */ @@ -195,6 +214,13 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset, */ target->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask; + /* + * update the header bits in the xsave header, indicating the + * presence of FP and SSE state. + */ + if (cpu_has_xsave) + target->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE; + return ret; } @@ -395,6 +421,12 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset, if (!ret) convert_to_fxsr(target, &env); + /* + * update the header bit in the xsave header, indicating the + * presence of FP. + */ + if (cpu_has_xsave) + target->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FP; return ret; } @@ -407,7 +439,6 @@ static inline int save_i387_fsave(struct _fpstate_ia32 __user *buf) struct task_struct *tsk = current; struct i387_fsave_struct *fp = &tsk->thread.xstate->fsave; - unlazy_fpu(tsk); fp->status = fp->swd; if (__copy_to_user(buf, fp, sizeof(struct i387_fsave_struct))) return -1; @@ -421,8 +452,6 @@ static int save_i387_fxsave(struct _fpstate_ia32 __user *buf) struct user_i387_ia32_struct env; int err = 0; - unlazy_fpu(tsk); - convert_from_fxsr(&env, tsk); if (__copy_to_user(buf, &env, sizeof(env))) return -1; @@ -432,16 +461,40 @@ static int save_i387_fxsave(struct _fpstate_ia32 __user *buf) if (err) return -1; - if (__copy_to_user(&buf->_fxsr_env[0], fx, - sizeof(struct i387_fxsave_struct))) + if (__copy_to_user(&buf->_fxsr_env[0], fx, xstate_size)) return -1; return 1; } -int save_i387_ia32(struct _fpstate_ia32 __user *buf) +static int save_i387_xsave(void __user *buf) +{ + struct _fpstate_ia32 __user *fx = buf; + int err = 0; + + if (save_i387_fxsave(fx) < 0) + return -1; + + err = __copy_to_user(&fx->sw_reserved, &fx_sw_reserved_ia32, + sizeof(struct _fpx_sw_bytes)); + err |= __put_user(FP_XSTATE_MAGIC2, + (__u32 __user *) (buf + sig_xstate_ia32_size + - FP_XSTATE_MAGIC2_SIZE)); + if (err) + return -1; + + return 1; +} + +int save_i387_xstate_ia32(void __user *buf) { + struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf; + struct task_struct *tsk = current; + if (!used_math()) return 0; + + if (!access_ok(VERIFY_WRITE, buf, sig_xstate_ia32_size)) + return -EACCES; /* * This will cause a "finit" to be triggered by the next * attempted FPU operation by the 'current' process. @@ -451,13 +504,17 @@ int save_i387_ia32(struct _fpstate_ia32 __user *buf) if (!HAVE_HWFP) { return fpregs_soft_get(current, NULL, 0, sizeof(struct user_i387_ia32_struct), - NULL, buf) ? -1 : 1; + NULL, fp) ? -1 : 1; } + unlazy_fpu(tsk); + + if (cpu_has_xsave) + return save_i387_xsave(fp); if (cpu_has_fxsr) - return save_i387_fxsave(buf); + return save_i387_fxsave(fp); else - return save_i387_fsave(buf); + return save_i387_fsave(fp); } static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf) @@ -468,14 +525,15 @@ static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf) sizeof(struct i387_fsave_struct)); } -static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf) +static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf, + unsigned int size) { struct task_struct *tsk = current; struct user_i387_ia32_struct env; int err; err = __copy_from_user(&tsk->thread.xstate->fxsave, &buf->_fxsr_env[0], - sizeof(struct i387_fxsave_struct)); + size); /* mxcsr reserved bits must be masked to zero for security reasons */ tsk->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask; if (err || __copy_from_user(&env, buf, sizeof(env))) @@ -485,14 +543,69 @@ static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf) return 0; } -int restore_i387_ia32(struct _fpstate_ia32 __user *buf) +static int restore_i387_xsave(void __user *buf) +{ + struct _fpx_sw_bytes fx_sw_user; + struct _fpstate_ia32 __user *fx_user = + ((struct _fpstate_ia32 __user *) buf); + struct i387_fxsave_struct __user *fx = + (struct i387_fxsave_struct __user *) &fx_user->_fxsr_env[0]; + struct xsave_hdr_struct *xsave_hdr = + ¤t->thread.xstate->xsave.xsave_hdr; + u64 mask; + int err; + + if (check_for_xstate(fx, buf, &fx_sw_user)) + goto fx_only; + + mask = fx_sw_user.xstate_bv; + + err = restore_i387_fxsave(buf, fx_sw_user.xstate_size); + + xsave_hdr->xstate_bv &= pcntxt_mask; + /* + * These bits must be zero. + */ + xsave_hdr->reserved1[0] = xsave_hdr->reserved1[1] = 0; + + /* + * Init the state that is not present in the memory layout + * and enabled by the OS. + */ + mask = ~(pcntxt_mask & ~mask); + xsave_hdr->xstate_bv &= mask; + + return err; +fx_only: + /* + * Couldn't find the extended state information in the memory + * layout. Restore the FP/SSE and init the other extended state + * enabled by the OS. + */ + xsave_hdr->xstate_bv = XSTATE_FPSSE; + return restore_i387_fxsave(buf, sizeof(struct i387_fxsave_struct)); +} + +int restore_i387_xstate_ia32(void __user *buf) { int err; struct task_struct *tsk = current; + struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf; if (HAVE_HWFP) clear_fpu(tsk); + if (!buf) { + if (used_math()) { + clear_fpu(tsk); + clear_used_math(); + } + + return 0; + } else + if (!access_ok(VERIFY_READ, buf, sig_xstate_ia32_size)) + return -EACCES; + if (!used_math()) { err = init_fpu(tsk); if (err) @@ -500,14 +613,17 @@ int restore_i387_ia32(struct _fpstate_ia32 __user *buf) } if (HAVE_HWFP) { - if (cpu_has_fxsr) - err = restore_i387_fxsave(buf); + if (cpu_has_xsave) + err = restore_i387_xsave(buf); + else if (cpu_has_fxsr) + err = restore_i387_fxsave(fp, sizeof(struct + i387_fxsave_struct)); else - err = restore_i387_fsave(buf); + err = restore_i387_fsave(fp); } else { err = fpregs_soft_set(current, NULL, 0, sizeof(struct user_i387_ia32_struct), - NULL, buf) != 0; + NULL, fp) != 0; } set_used_math(); diff --git a/arch/x86/kernel/sigframe.h b/arch/x86/kernel/sigframe.h index 72bbb519d2d..6dd7e2b70a4 100644 --- a/arch/x86/kernel/sigframe.h +++ b/arch/x86/kernel/sigframe.h @@ -3,9 +3,18 @@ struct sigframe { char __user *pretcode; int sig; struct sigcontext sc; - struct _fpstate fpstate; + /* + * fpstate is unused. fpstate is moved/allocated after + * retcode[] below. This movement allows to have the FP state and the + * future state extensions (xsave) stay together. + * And at the same time retaining the unused fpstate, prevents changing + * the offset of extramask[] in the sigframe and thus prevent any + * legacy application accessing/modifying it. + */ + struct _fpstate fpstate_unused; unsigned long extramask[_NSIG_WORDS-1]; char retcode[8]; + /* fp state follows here */ }; struct rt_sigframe { @@ -15,13 +24,14 @@ struct rt_sigframe { void __user *puc; struct siginfo info; struct ucontext uc; - struct _fpstate fpstate; char retcode[8]; + /* fp state follows here */ }; #else struct rt_sigframe { char __user *pretcode; struct ucontext uc; struct siginfo info; + /* fp state follows here */ }; #endif diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c index 0c727f64e79..8d380b699c0 100644 --- a/arch/x86/kernel/signal_32.c +++ b/arch/x86/kernel/signal_32.c @@ -160,28 +160,14 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, } { - struct _fpstate __user *buf; + void __user *buf; err |= __get_user(buf, &sc->fpstate); - if (buf) { - if (!access_ok(VERIFY_READ, buf, sizeof(*buf))) - goto badframe; - err |= restore_i387(buf); - } else { - struct task_struct *me = current; - - if (used_math()) { - clear_fpu(me); - clear_used_math(); - } - } + err |= restore_i387_xstate(buf); } err |= __get_user(*pax, &sc->ax); return err; - -badframe: - return 1; } asmlinkage unsigned long sys_sigreturn(unsigned long __unused) @@ -263,7 +249,7 @@ badframe: * Set up a signal frame. */ static int -setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate, +setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate, struct pt_regs *regs, unsigned long mask) { int tmp, err = 0; @@ -290,7 +276,7 @@ setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate, err |= __put_user(regs->sp, &sc->sp_at_signal); err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss); - tmp = save_i387(fpstate); + tmp = save_i387_xstate(fpstate); if (tmp < 0) err = 1; else @@ -307,7 +293,8 @@ setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate, * Determine which stack to use.. */ static inline void __user * -get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size) +get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size, + void **fpstate) { unsigned long sp; @@ -333,6 +320,11 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size) sp = (unsigned long) ka->sa.sa_restorer; } + if (used_math()) { + sp = sp - sig_xstate_size; + *fpstate = (struct _fpstate *) sp; + } + sp -= frame_size; /* * Align the stack pointer according to the i386 ABI, @@ -351,8 +343,9 @@ setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, void __user *restorer; int err = 0; int usig; + void __user *fpstate = NULL; - frame = get_sigframe(ka, regs, sizeof(*frame)); + frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; @@ -367,7 +360,7 @@ setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, if (err) goto give_sigsegv; - err = setup_sigcontext(&frame->sc, &frame->fpstate, regs, set->sig[0]); + err = setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]); if (err) goto give_sigsegv; @@ -428,8 +421,9 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, void __user *restorer; int err = 0; int usig; + void __user *fpstate = NULL; - frame = get_sigframe(ka, regs, sizeof(*frame)); + frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; @@ -448,13 +442,16 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, goto give_sigsegv; /* Create the ucontext. */ - err |= __put_user(0, &frame->uc.uc_flags); + if (cpu_has_xsave) + err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags); + else + err |= __put_user(0, &frame->uc.uc_flags); err |= __put_user(0, &frame->uc.uc_link); err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); err |= __put_user(sas_ss_flags(regs->sp), &frame->uc.uc_stack.ss_flags); err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); - err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate, + err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, regs, set->sig[0]); err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); if (err) diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c index 2f146405005..4665b598a37 100644 --- a/arch/x86/kernel/signal_64.c +++ b/arch/x86/kernel/signal_64.c @@ -55,69 +55,6 @@ sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, } /* - * Signal frame handlers. - */ - -static inline int save_i387(struct _fpstate __user *buf) -{ - struct task_struct *tsk = current; - int err = 0; - - BUILD_BUG_ON(sizeof(struct user_i387_struct) != - sizeof(tsk->thread.xstate->fxsave)); - - if ((unsigned long)buf % 16) - printk("save_i387: bad fpstate %p\n", buf); - - if (!used_math()) - return 0; - clear_used_math(); /* trigger finit */ - if (task_thread_info(tsk)->status & TS_USEDFPU) { - err = save_i387_checking((struct i387_fxsave_struct __user *) - buf); - if (err) - return err; - task_thread_info(tsk)->status &= ~TS_USEDFPU; - stts(); - } else { - if (__copy_to_user(buf, &tsk->thread.xstate->fxsave, - sizeof(struct i387_fxsave_struct))) - return -1; - } - return 1; -} - -/* - * This restores directly out of user space. Exceptions are handled. - */ -static inline int restore_i387(struct _fpstate __user *buf) -{ - struct task_struct *tsk = current; - int err; - - if (!used_math()) { - err = init_fpu(tsk); - if (err) - return err; - } - - if (!(task_thread_info(current)->status & TS_USEDFPU)) { - clts(); - task_thread_info(current)->status |= TS_USEDFPU; - } - err = restore_fpu_checking((__force struct i387_fxsave_struct *)buf); - if (unlikely(err)) { - /* - * Encountered an error while doing the restore from the - * user buffer, clear the fpu state. - */ - clear_fpu(tsk); - clear_used_math(); - } - return err; -} - -/* * Do a signal return; undo the signal stack. */ static int @@ -161,25 +98,11 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, { struct _fpstate __user * buf; err |= __get_user(buf, &sc->fpstate); - - if (buf) { - if (!access_ok(VERIFY_READ, buf, sizeof(*buf))) - goto badframe; - err |= restore_i387(buf); - } else { - struct task_struct *me = current; - if (used_math()) { - clear_fpu(me); - clear_used_math(); - } - } + err |= restore_i387_xstate(buf); } err |= __get_user(*pax, &sc->ax); return err; - -badframe: - return 1; } asmlinkage long sys_rt_sigreturn(struct pt_regs *regs) @@ -270,26 +193,23 @@ get_stack(struct k_sigaction *ka, struct pt_regs *regs, unsigned long size) sp = current->sas_ss_sp + current->sas_ss_size; } - return (void __user *)round_down(sp - size, 16); + return (void __user *)round_down(sp - size, 64); } static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set, struct pt_regs * regs) { struct rt_sigframe __user *frame; - struct _fpstate __user *fp = NULL; + void __user *fp = NULL; int err = 0; struct task_struct *me = current; if (used_math()) { - fp = get_stack(ka, regs, sizeof(struct _fpstate)); + fp = get_stack(ka, regs, sig_xstate_size); frame = (void __user *)round_down( (unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8; - if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate))) - goto give_sigsegv; - - if (save_i387(fp) < 0) + if (save_i387_xstate(fp) < 0) err |= -1; } else frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8; @@ -304,7 +224,10 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, } /* Create the ucontext. */ - err |= __put_user(0, &frame->uc.uc_flags); + if (cpu_has_xsave) + err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags); + else + err |= __put_user(0, &frame->uc.uc_flags); err |= __put_user(0, &frame->uc.uc_link); err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp); err |= __put_user(sas_ss_flags(regs->sp), diff --git a/arch/x86/kernel/traps_32.c b/arch/x86/kernel/traps_32.c index 03df8e45e5a..da5a5964fcc 100644 --- a/arch/x86/kernel/traps_32.c +++ b/arch/x86/kernel/traps_32.c @@ -1228,7 +1228,6 @@ void __init trap_init(void) set_bit(SYSCALL_VECTOR, used_vectors); - init_thread_xstate(); /* * Should be a barrier for any external CPU state: */ diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c index 513caaca711..38eb76156a4 100644 --- a/arch/x86/kernel/traps_64.c +++ b/arch/x86/kernel/traps_64.c @@ -1134,7 +1134,7 @@ asmlinkage void math_state_restore(void) /* * Paranoid restore. send a SIGSEGV if we fail to restore the state. */ - if (unlikely(restore_fpu_checking(&me->thread.xstate->fxsave))) { + if (unlikely(restore_fpu_checking(me))) { stts(); force_sig(SIGSEGV, me); return; @@ -1173,10 +1173,6 @@ void __init trap_init(void) set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall); #endif /* - * initialize the per thread extended state: - */ - init_thread_xstate(); - /* * Should be a barrier for any external CPU state: */ cpu_init(); diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c new file mode 100644 index 00000000000..07713d64deb --- /dev/null +++ b/arch/x86/kernel/xsave.c @@ -0,0 +1,316 @@ +/* + * xsave/xrstor support. + * + * Author: Suresh Siddha <suresh.b.siddha@intel.com> + */ +#include <linux/bootmem.h> +#include <linux/compat.h> +#include <asm/i387.h> +#ifdef CONFIG_IA32_EMULATION +#include <asm/sigcontext32.h> +#endif +#include <asm/xcr.h> + +/* + * Supported feature mask by the CPU and the kernel. + */ +u64 pcntxt_mask; + +struct _fpx_sw_bytes fx_sw_reserved; +#ifdef CONFIG_IA32_EMULATION +struct _fpx_sw_bytes fx_sw_reserved_ia32; +#endif + +/* + * Check for the presence of extended state information in the + * user fpstate pointer in the sigcontext. + */ +int check_for_xstate(struct i387_fxsave_struct __user *buf, + void __user *fpstate, + struct _fpx_sw_bytes *fx_sw_user) +{ + int min_xstate_size = sizeof(struct i387_fxsave_struct) + + sizeof(struct xsave_hdr_struct); + unsigned int magic2; + int err; + + err = __copy_from_user(fx_sw_user, &buf->sw_reserved[0], + sizeof(struct _fpx_sw_bytes)); + + if (err) + return err; + + /* + * First Magic check failed. + */ + if (fx_sw_user->magic1 != FP_XSTATE_MAGIC1) + return -1; + + /* + * Check for error scenarios. + */ + if (fx_sw_user->xstate_size < min_xstate_size || + fx_sw_user->xstate_size > xstate_size || + fx_sw_user->xstate_size > fx_sw_user->extended_size) + return -1; + + err = __get_user(magic2, (__u32 *) (((void *)fpstate) + + fx_sw_user->extended_size - + FP_XSTATE_MAGIC2_SIZE)); + /* + * Check for the presence of second magic word at the end of memory + * layout. This detects the case where the user just copied the legacy + * fpstate layout with out copying the extended state information + * in the memory layout. + */ + if (err || magic2 != FP_XSTATE_MAGIC2) + return -1; + + return 0; +} + +#ifdef CONFIG_X86_64 +/* + * Signal frame handlers. + */ + +int save_i387_xstate(void __user *buf) +{ + struct task_struct *tsk = current; + int err = 0; + + if (!access_ok(VERIFY_WRITE, buf, sig_xstate_size)) + return -EACCES; + + BUG_ON(sig_xstate_size < xstate_size); + + if ((unsigned long)buf % 64) + printk("save_i387_xstate: bad fpstate %p\n", buf); + + if (!used_math()) + return 0; + clear_used_math(); /* trigger finit */ + if (task_thread_info(tsk)->status & TS_USEDFPU) { + /* + * Start with clearing the user buffer. This will present a + * clean context for the bytes not touched by the fxsave/xsave. + */ + __clear_user(buf, sig_xstate_size); + + if (task_thread_info(tsk)->status & TS_XSAVE) + err = xsave_user(buf); + else + err = fxsave_user(buf); + + if (err) + return err; + task_thread_info(tsk)->status &= ~TS_USEDFPU; + stts(); + } else { + if (__copy_to_user(buf, &tsk->thread.xstate->fxsave, + xstate_size)) + return -1; + } + + if (task_thread_info(tsk)->status & TS_XSAVE) { + struct _fpstate __user *fx = buf; + + err = __copy_to_user(&fx->sw_reserved, &fx_sw_reserved, + sizeof(struct _fpx_sw_bytes)); + + err |= __put_user(FP_XSTATE_MAGIC2, + (__u32 __user *) (buf + sig_xstate_size + - FP_XSTATE_MAGIC2_SIZE)); + } + + return 1; +} + +/* + * Restore the extended state if present. Otherwise, restore the FP/SSE + * state. + */ +int restore_user_xstate(void __user *buf) +{ + struct _fpx_sw_bytes fx_sw_user; + u64 mask; + int err; + + if (((unsigned long)buf % 64) || + check_for_xstate(buf, buf, &fx_sw_user)) + goto fx_only; + + mask = fx_sw_user.xstate_bv; + + /* + * restore the state passed by the user. + */ + err = xrestore_user(buf, mask); + if (err) + return err; + + /* + * init the state skipped by the user. + */ + mask = pcntxt_mask & ~mask; + + xrstor_state(init_xstate_buf, mask); + + return 0; + +fx_only: + /* + * couldn't find the extended state information in the + * memory layout. Restore just the FP/SSE and init all + * the other extended state. + */ + xrstor_state(init_xstate_buf, pcntxt_mask & ~XSTATE_FPSSE); + return fxrstor_checking((__force struct i387_fxsave_struct *)buf); +} + +/* + * This restores directly out of user space. Exceptions are handled. + */ +int restore_i387_xstate(void __user *buf) +{ + struct task_struct *tsk = current; + int err = 0; + + if (!buf) { + if (used_math()) + goto clear; + return 0; + } else + if (!access_ok(VERIFY_READ, buf, sig_xstate_size)) + return -EACCES; + + if (!used_math()) { + err = init_fpu(tsk); + if (err) + return err; + } + + if (!(task_thread_info(current)->status & TS_USEDFPU)) { + clts(); + task_thread_info(current)->status |= TS_USEDFPU; + } + if (task_thread_info(tsk)->status & TS_XSAVE) + err = restore_user_xstate(buf); + else + err = fxrstor_checking((__force struct i387_fxsave_struct *) + buf); + if (unlikely(err)) { + /* + * Encountered an error while doing the restore from the + * user buffer, clear the fpu state. + */ +clear: + clear_fpu(tsk); + clear_used_math(); + } + return err; +} +#endif + +/* + * Prepare the SW reserved portion of the fxsave memory layout, indicating + * the presence of the extended state information in the memory layout + * pointed by the fpstate pointer in the sigcontext. + * This will be saved when ever the FP and extended state context is + * saved on the user stack during the signal handler delivery to the user. + */ +void prepare_fx_sw_frame(void) +{ + int size_extended = (xstate_size - sizeof(struct i387_fxsave_struct)) + + FP_XSTATE_MAGIC2_SIZE; + + sig_xstate_size = sizeof(struct _fpstate) + size_extended; + +#ifdef CONFIG_IA32_EMULATION + sig_xstate_ia32_size = sizeof(struct _fpstate_ia32) + size_extended; +#endif + + memset(&fx_sw_reserved, 0, sizeof(fx_sw_reserved)); + + fx_sw_reserved.magic1 = FP_XSTATE_MAGIC1; + fx_sw_reserved.extended_size = sig_xstate_size; + fx_sw_reserved.xstate_bv = pcntxt_mask; + fx_sw_reserved.xstate_size = xstate_size; +#ifdef CONFIG_IA32_EMULATION + memcpy(&fx_sw_reserved_ia32, &fx_sw_reserved, + sizeof(struct _fpx_sw_bytes)); + fx_sw_reserved_ia32.extended_size = sig_xstate_ia32_size; +#endif +} + +/* + * Represents init state for the supported extended state. + */ +struct xsave_struct *init_xstate_buf; + +#ifdef CONFIG_X86_64 +unsigned int sig_xstate_size = sizeof(struct _fpstate); +#endif + +/* + * Enable the extended processor state save/restore feature + */ +void __cpuinit xsave_init(void) +{ + if (!cpu_has_xsave) + return; + + set_in_cr4(X86_CR4_OSXSAVE); + + /* + * Enable all the features that the HW is capable of + * and the Linux kernel is aware of. + */ + xsetbv(XCR_XFEATURE_ENABLED_MASK, pcntxt_mask); +} + +/* + * setup the xstate image representing the init state + */ +void setup_xstate_init(void) +{ + init_xstate_buf = alloc_bootmem(xstate_size); + init_xstate_buf->i387.mxcsr = MXCSR_DEFAULT; +} + +/* + * Enable and initialize the xsave feature. + */ +void __init xsave_cntxt_init(void) +{ + unsigned int eax, ebx, ecx, edx; + + cpuid_count(0xd, 0, &eax, &ebx, &ecx, &edx); + pcntxt_mask = eax + ((u64)edx << 32); + + if ((pcntxt_mask & XSTATE_FPSSE) != XSTATE_FPSSE) { + printk(KERN_ERR "FP/SSE not shown under xsave features 0x%llx\n", + pcntxt_mask); + BUG(); + } + + /* + * for now OS knows only about FP/SSE + */ + pcntxt_mask = pcntxt_mask & XCNTXT_MASK; + xsave_init(); + + /* + * Recompute the context size for enabled features + */ + cpuid_count(0xd, 0, &eax, &ebx, &ecx, &edx); + xstate_size = ebx; + + prepare_fx_sw_frame(); + + setup_xstate_init(); + + printk(KERN_INFO "xsave/xrstor: enabled xstate_bv 0x%llx, " + "cntxt size 0x%x\n", + pcntxt_mask, xstate_size); +} diff --git a/arch/x86/power/cpu_32.c b/arch/x86/power/cpu_32.c index d3e083dea72..274d06082f4 100644 --- a/arch/x86/power/cpu_32.c +++ b/arch/x86/power/cpu_32.c @@ -11,6 +11,7 @@ #include <linux/suspend.h> #include <asm/mtrr.h> #include <asm/mce.h> +#include <asm/xcr.h> static struct saved_context saved_context; @@ -126,6 +127,12 @@ static void __restore_processor_state(struct saved_context *ctxt) if (boot_cpu_has(X86_FEATURE_SEP)) enable_sep_cpu(); + /* + * restore XCR0 for xsave capable cpu's. + */ + if (cpu_has_xsave) + xsetbv(XCR_XFEATURE_ENABLED_MASK, pcntxt_mask); + fix_processor_context(); do_fpu_end(); mtrr_ap_init(); diff --git a/arch/x86/power/cpu_64.c b/arch/x86/power/cpu_64.c index 66bdfb591fd..e3b6cf70d62 100644 --- a/arch/x86/power/cpu_64.c +++ b/arch/x86/power/cpu_64.c @@ -14,6 +14,7 @@ #include <asm/page.h> #include <asm/pgtable.h> #include <asm/mtrr.h> +#include <asm/xcr.h> static void fix_processor_context(void); @@ -122,6 +123,12 @@ static void __restore_processor_state(struct saved_context *ctxt) wrmsrl(MSR_GS_BASE, ctxt->gs_base); wrmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base); + /* + * restore XCR0 for xsave capable cpu's. + */ + if (cpu_has_xsave) + xsetbv(XCR_XFEATURE_ENABLED_MASK, pcntxt_mask); + fix_processor_context(); do_fpu_end(); |