diff options
| -rw-r--r-- | arch/x86/Kconfig.debug | 12 | ||||
| -rw-r--r-- | arch/x86/include/asm/fpu/internal.h | 17 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/core.c | 18 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/init.c | 12 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 11 |
5 files changed, 58 insertions, 12 deletions
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 72484a645f05..2fd3ebbb4e33 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -332,4 +332,16 @@ config X86_DEBUG_STATIC_CPU_HAS If unsure, say N. +config X86_DEBUG_FPU + bool "Debug the x86 FPU code" + depends on DEBUG_KERNEL + default y + ---help--- + If this option is enabled then there will be extra sanity + checks and (boot time) debug printouts added to the kernel. + This debugging adds some small amount of runtime overhead + to the kernel. + + If unsure, say N. + endmenu diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index a4c1b7dbf70e..d2a281bd5f45 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -59,6 +59,15 @@ extern void fpu__clear(struct fpu *fpu); extern void fpu__init_check_bugs(void); extern void fpu__resume_cpu(void); +/* + * Debugging facility: + */ +#ifdef CONFIG_X86_DEBUG_FPU +# define WARN_ON_FPU(x) WARN_ON_ONCE(x) +#else +# define WARN_ON_FPU(x) ({ 0; }) +#endif + DECLARE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx); /* @@ -296,6 +305,8 @@ static inline void __fpregs_deactivate_hw(void) /* Must be paired with an 'stts' (fpregs_deactivate_hw()) after! */ static inline void __fpregs_deactivate(struct fpu *fpu) { + WARN_ON_FPU(!fpu->fpregs_active); + fpu->fpregs_active = 0; this_cpu_write(fpu_fpregs_owner_ctx, NULL); } @@ -303,6 +314,8 @@ static inline void __fpregs_deactivate(struct fpu *fpu) /* Must be paired with a 'clts' (fpregs_activate_hw()) before! */ static inline void __fpregs_activate(struct fpu *fpu) { + WARN_ON_FPU(fpu->fpregs_active); + fpu->fpregs_active = 1; this_cpu_write(fpu_fpregs_owner_ctx, fpu); } @@ -433,8 +446,10 @@ switch_fpu_prepare(struct fpu *old_fpu, struct fpu *new_fpu, int cpu) static inline void switch_fpu_finish(struct fpu *new_fpu, fpu_switch_t fpu_switch) { if (fpu_switch.preload) { - if (unlikely(copy_fpstate_to_fpregs(new_fpu))) + if (unlikely(copy_fpstate_to_fpregs(new_fpu))) { + WARN_ON_FPU(1); fpu__clear(new_fpu); + } } } diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index c0661604a258..01a15503c3be 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -38,13 +38,13 @@ DEFINE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx); static void kernel_fpu_disable(void) { - WARN_ON(this_cpu_read(in_kernel_fpu)); + WARN_ON_FPU(this_cpu_read(in_kernel_fpu)); this_cpu_write(in_kernel_fpu, true); } static void kernel_fpu_enable(void) { - WARN_ON_ONCE(!this_cpu_read(in_kernel_fpu)); + WARN_ON_FPU(!this_cpu_read(in_kernel_fpu)); this_cpu_write(in_kernel_fpu, false); } @@ -109,7 +109,7 @@ void __kernel_fpu_begin(void) { struct fpu *fpu = ¤t->thread.fpu; - WARN_ON_ONCE(!irq_fpu_usable()); + WARN_ON_FPU(!irq_fpu_usable()); kernel_fpu_disable(); @@ -127,7 +127,7 @@ void __kernel_fpu_end(void) struct fpu *fpu = ¤t->thread.fpu; if (fpu->fpregs_active) { - if (WARN_ON(copy_fpstate_to_fpregs(fpu))) + if (WARN_ON_FPU(copy_fpstate_to_fpregs(fpu))) fpu__clear(fpu); } else { __fpregs_deactivate_hw(); @@ -187,7 +187,7 @@ EXPORT_SYMBOL_GPL(irq_ts_restore); */ void fpu__save(struct fpu *fpu) { - WARN_ON(fpu != ¤t->thread.fpu); + WARN_ON_FPU(fpu != ¤t->thread.fpu); preempt_disable(); if (fpu->fpregs_active) { @@ -233,7 +233,7 @@ EXPORT_SYMBOL_GPL(fpstate_init); */ static void fpu_copy(struct fpu *dst_fpu, struct fpu *src_fpu) { - WARN_ON(src_fpu != ¤t->thread.fpu); + WARN_ON_FPU(src_fpu != ¤t->thread.fpu); /* * Don't let 'init optimized' areas of the XSAVE area @@ -284,7 +284,7 @@ int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu) */ void fpu__activate_curr(struct fpu *fpu) { - WARN_ON_ONCE(fpu != ¤t->thread.fpu); + WARN_ON_FPU(fpu != ¤t->thread.fpu); if (!fpu->fpstate_active) { fpstate_init(&fpu->state); @@ -321,7 +321,7 @@ EXPORT_SYMBOL_GPL(fpu__activate_curr); */ void fpu__activate_stopped(struct fpu *child_fpu) { - WARN_ON_ONCE(child_fpu == ¤t->thread.fpu); + WARN_ON_FPU(child_fpu == ¤t->thread.fpu); if (child_fpu->fpstate_active) { child_fpu->last_cpu = -1; @@ -407,7 +407,7 @@ static inline void copy_init_fpstate_to_fpregs(void) */ void fpu__clear(struct fpu *fpu) { - WARN_ON_ONCE(fpu != ¤t->thread.fpu); /* Almost certainly an anomaly */ + WARN_ON_FPU(fpu != ¤t->thread.fpu); /* Almost certainly an anomaly */ if (!use_eager_fpu()) { /* FPU state will be reallocated lazily at the first use. */ diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index a9e506a99a83..e9f1d6e62146 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -143,6 +143,11 @@ EXPORT_SYMBOL_GPL(xstate_size); */ static void __init fpu__init_system_xstate_size_legacy(void) { + static int on_boot_cpu = 1; + + WARN_ON_FPU(!on_boot_cpu); + on_boot_cpu = 0; + /* * Note that xstate_size might be overwriten later during * fpu__init_system_xstate(). @@ -214,7 +219,12 @@ __setup("eagerfpu=", eager_fpu_setup); */ static void __init fpu__init_system_ctx_switch(void) { - WARN_ON(current->thread.fpu.fpstate_active); + static bool on_boot_cpu = 1; + + WARN_ON_FPU(!on_boot_cpu); + on_boot_cpu = 0; + + WARN_ON_FPU(current->thread.fpu.fpstate_active); current_thread_info()->status = 0; /* Auto enable eagerfpu for xsaveopt */ diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 201f08feb259..5724098adf1b 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -262,6 +262,11 @@ static void __init setup_xstate_comp(void) */ static void __init setup_init_fpu_buf(void) { + static int on_boot_cpu = 1; + + WARN_ON_FPU(!on_boot_cpu); + on_boot_cpu = 0; + if (!cpu_has_xsave) return; @@ -317,6 +322,10 @@ static void __init init_xstate_size(void) void __init fpu__init_system_xstate(void) { unsigned int eax, ebx, ecx, edx; + static int on_boot_cpu = 1; + + WARN_ON_FPU(!on_boot_cpu); + on_boot_cpu = 0; if (!cpu_has_xsave) { pr_info("x86/fpu: Legacy x87 FPU detected.\n"); @@ -324,7 +333,7 @@ void __init fpu__init_system_xstate(void) } if (boot_cpu_data.cpuid_level < XSTATE_CPUID) { - WARN(1, "x86/fpu: XSTATE_CPUID missing!\n"); + WARN_ON_FPU(1); return; } |