Merge branch 'linus' into stackprotector

Conflicts:
	arch/x86/include/asm/pda.h
	kernel/fork.c

1 files changed, 137 insertions, 0 deletions

diff --git a/arch/x86/include/asm/pda.h b/arch/x86/include/asm/pda.h
new file mode 100644
index 000000000000..3fea2fdb3302
--- /dev/null
+++ b/arch/x86/include/asm/pda.h
@@ -0,0 +1,137 @@
+#ifndef _ASM_X86_PDA_H
+#define _ASM_X86_PDA_H
+
+#ifndef __ASSEMBLY__
+#include <linux/stddef.h>
+#include <linux/types.h>
+#include <linux/cache.h>
+#include <asm/page.h>
+
+/* Per processor datastructure. %gs points to it while the kernel runs */
+struct x8664_pda {
+        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 -1 */
+        unsigned int cpunumber;         /* 36 Logical CPU number */
+        unsigned long stack_canary;     /* 40 stack canary value */
+                                        /* gcc-ABI: this canary MUST be at
+                                           offset 40!!! */
+        char *irqstackptr;
+        short nodenumber;               /* number of current node (32k max) */
+        short in_bootmem;               /* pda lives in bootmem */
+        unsigned int __softirq_pending;
+        unsigned int __nmi_count;       /* number of NMI on this CPUs */
+        short mmu_state;
+        short isidle;
+        struct mm_struct *active_mm;
+        unsigned apic_timer_irqs;
+        unsigned irq0_irqs;
+        unsigned irq_resched_count;
+        unsigned irq_call_count;
+        unsigned irq_tlb_count;
+        unsigned irq_thermal_count;
+        unsigned irq_threshold_count;
+        unsigned irq_spurious_count;
+} ____cacheline_aligned_in_smp;
+
+extern struct x8664_pda **_cpu_pda;
+extern void pda_init(int);
+
+#define cpu_pda(i) (_cpu_pda[i])
+
+/*
+ * 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.
+ */
+extern void __bad_pda_field(void) __attribute__((noreturn));
+
+/*
+ * 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(_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)
+
+#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)
+
+#define refresh_stack_canary() write_pda(stack_canary, current->stack_canary)
+
+#endif /* _ASM_X86_PDA_H */