/* 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 */
+ short mmu_state;
+ short isidle;
struct mm_struct *active_mm;
- int mmu_state;
unsigned apic_timer_irqs;
} ____cacheline_aligned_in_smp;
* 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)
#define sub_pda(field,val) pda_to_op("sub",field,val)
#define or_pda(field,val) pda_to_op("or",field,val)
+/* This is not atomic against other CPUs -- CPU preemption needs to be off */
+#define test_and_clear_bit_pda(bit,field) ({ \
+ int old__; \
+ asm volatile("btr %2,%%gs:%c3\n\tsbbl %0,%0" \
+ : "=r" (old__), "+m" (_proxy_pda.field) \
+ : "dIr" (bit), "i" (pda_offset(field)) : "memory"); \
+ old__; \
+})
+
#endif
#define PDA_STACKOFFSET (5*8)
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