diff options
Diffstat (limited to 'include/asm-x86_64/pda.h')
| -rw-r--r-- | include/asm-x86_64/pda.h | 109 |
1 files changed, 69 insertions, 40 deletions
diff --git a/include/asm-x86_64/pda.h b/include/asm-x86_64/pda.h index b47c3df..14996d9 100644 --- a/include/asm-x86_64/pda.h +++ b/include/asm-x86_64/pda.h @@ -9,20 +9,24 @@ /* Per processor datastructure. %gs points to it while the kernel runs */ struct x8664_pda { - struct task_struct *pcurrent; /* Current process */ - unsigned long data_offset; /* Per cpu data offset from linker address */ - unsigned long kernelstack; /* top of kernel stack for current */ - unsigned long oldrsp; /* user rsp for system call */ -#if DEBUG_STKSZ > EXCEPTION_STKSZ - unsigned long debugstack; /* #DB/#BP stack. */ + struct task_struct *pcurrent; /* 0 Current process */ + unsigned long data_offset; /* 8 Per cpu data offset from linker + address */ + unsigned long kernelstack; /* 16 top of kernel stack for current */ + unsigned long oldrsp; /* 24 user rsp for system call */ + int irqcount; /* 32 Irq nesting counter. Starts with -1 */ + int cpunumber; /* 36 Logical CPU number */ +#ifdef CONFIG_CC_STACKPROTECTOR + unsigned long stack_canary; /* 40 stack canary value */ + /* gcc-ABI: this canary MUST be at + offset 40!!! */ #endif - int irqcount; /* Irq nesting counter. Starts with -1 */ - int cpunumber; /* Logical CPU number */ - char *irqstackptr; /* top of irqstack */ + char *irqstackptr; int nodenumber; /* number of current node */ unsigned int __softirq_pending; unsigned int __nmi_count; /* number of NMI on this CPUs */ - int mmu_state; + short mmu_state; + short isidle; struct mm_struct *active_mm; unsigned apic_timer_irqs; } ____cacheline_aligned_in_smp; @@ -36,44 +40,69 @@ extern struct x8664_pda boot_cpu_pda[]; * There is no fast way to get the base address of the PDA, all the accesses * have to mention %fs/%gs. So it needs to be done this Torvaldian way. */ -#define sizeof_field(type,field) (sizeof(((type *)0)->field)) -#define typeof_field(type,field) typeof(((type *)0)->field) +extern void __bad_pda_field(void) __attribute__((noreturn)); -extern void __bad_pda_field(void); +/* + * proxy_pda doesn't actually exist, but tell gcc it is accessed for + * all PDA accesses so it gets read/write dependencies right. + */ +extern struct x8664_pda _proxy_pda; #define pda_offset(field) offsetof(struct x8664_pda, field) -#define pda_to_op(op,field,val) do { \ - typedef typeof_field(struct x8664_pda, field) T__; \ - switch (sizeof_field(struct x8664_pda, field)) { \ -case 2: \ -asm volatile(op "w %0,%%gs:%P1"::"ri" ((T__)val),"i"(pda_offset(field)):"memory"); break; \ -case 4: \ -asm volatile(op "l %0,%%gs:%P1"::"ri" ((T__)val),"i"(pda_offset(field)):"memory"); break; \ -case 8: \ -asm volatile(op "q %0,%%gs:%P1"::"ri" ((T__)val),"i"(pda_offset(field)):"memory"); break; \ - default: __bad_pda_field(); \ - } \ +#define pda_to_op(op,field,val) do { \ + typedef typeof(_proxy_pda.field) T__; \ + if (0) { T__ tmp__; tmp__ = (val); } /* type checking */ \ + switch (sizeof(_proxy_pda.field)) { \ + case 2: \ + asm(op "w %1,%%gs:%c2" : \ + "+m" (_proxy_pda.field) : \ + "ri" ((T__)val), \ + "i"(pda_offset(field))); \ + break; \ + case 4: \ + asm(op "l %1,%%gs:%c2" : \ + "+m" (_proxy_pda.field) : \ + "ri" ((T__)val), \ + "i" (pda_offset(field))); \ + break; \ + case 8: \ + asm(op "q %1,%%gs:%c2": \ + "+m" (_proxy_pda.field) : \ + "ri" ((T__)val), \ + "i"(pda_offset(field))); \ + break; \ + default: \ + __bad_pda_field(); \ + } \ } while (0) -/* - * AK: PDA read accesses should be neither volatile nor have an memory clobber. - * Unfortunately removing them causes all hell to break lose currently. - */ -#define pda_from_op(op,field) ({ \ - typeof_field(struct x8664_pda, field) ret__; \ - switch (sizeof_field(struct x8664_pda, field)) { \ -case 2: \ -asm volatile(op "w %%gs:%P1,%0":"=r" (ret__):"i"(pda_offset(field)):"memory"); break;\ -case 4: \ -asm volatile(op "l %%gs:%P1,%0":"=r" (ret__):"i"(pda_offset(field)):"memory"); break;\ -case 8: \ -asm volatile(op "q %%gs:%P1,%0":"=r" (ret__):"i"(pda_offset(field)):"memory"); break;\ - default: __bad_pda_field(); \ - } \ +#define pda_from_op(op,field) ({ \ + typeof(_proxy_pda.field) ret__; \ + switch (sizeof(_proxy_pda.field)) { \ + case 2: \ + asm(op "w %%gs:%c1,%0" : \ + "=r" (ret__) : \ + "i" (pda_offset(field)), \ + "m" (_proxy_pda.field)); \ + break; \ + case 4: \ + asm(op "l %%gs:%c1,%0": \ + "=r" (ret__): \ + "i" (pda_offset(field)), \ + "m" (_proxy_pda.field)); \ + break; \ + case 8: \ + asm(op "q %%gs:%c1,%0": \ + "=r" (ret__) : \ + "i" (pda_offset(field)), \ + "m" (_proxy_pda.field)); \ + break; \ + default: \ + __bad_pda_field(); \ + } \ ret__; }) - #define read_pda(field) pda_from_op("mov",field) #define write_pda(field,val) pda_to_op("mov",field,val) #define add_pda(field,val) pda_to_op("add",field,val) |