1 files changed, 105 insertions, 0 deletions

diff --git a/arch/x86/kernel/perf_regs.c b/arch/x86/kernel/perf_regs.c
new file mode 100644
index 000000000000..e309cc5c276e
--- /dev/null
+++ b/arch/x86/kernel/perf_regs.c
@@ -0,0 +1,105 @@
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/perf_event.h>
+#include <linux/bug.h>
+#include <linux/stddef.h>
+#include <asm/perf_regs.h>
+#include <asm/ptrace.h>
+
+#ifdef CONFIG_X86_32
+#define PERF_REG_X86_MAX PERF_REG_X86_32_MAX
+#else
+#define PERF_REG_X86_MAX PERF_REG_X86_64_MAX
+#endif
+
+#define PT_REGS_OFFSET(id, r) [id] = offsetof(struct pt_regs, r)
+
+static unsigned int pt_regs_offset[PERF_REG_X86_MAX] = {
+        PT_REGS_OFFSET(PERF_REG_X86_AX, ax),
+        PT_REGS_OFFSET(PERF_REG_X86_BX, bx),
+        PT_REGS_OFFSET(PERF_REG_X86_CX, cx),
+        PT_REGS_OFFSET(PERF_REG_X86_DX, dx),
+        PT_REGS_OFFSET(PERF_REG_X86_SI, si),
+        PT_REGS_OFFSET(PERF_REG_X86_DI, di),
+        PT_REGS_OFFSET(PERF_REG_X86_BP, bp),
+        PT_REGS_OFFSET(PERF_REG_X86_SP, sp),
+        PT_REGS_OFFSET(PERF_REG_X86_IP, ip),
+        PT_REGS_OFFSET(PERF_REG_X86_FLAGS, flags),
+        PT_REGS_OFFSET(PERF_REG_X86_CS, cs),
+        PT_REGS_OFFSET(PERF_REG_X86_SS, ss),
+#ifdef CONFIG_X86_32
+        PT_REGS_OFFSET(PERF_REG_X86_DS, ds),
+        PT_REGS_OFFSET(PERF_REG_X86_ES, es),
+        PT_REGS_OFFSET(PERF_REG_X86_FS, fs),
+        PT_REGS_OFFSET(PERF_REG_X86_GS, gs),
+#else
+        /*
+         * The pt_regs struct does not store
+         * ds, es, fs, gs in 64 bit mode.
+         */
+        (unsigned int) -1,
+        (unsigned int) -1,
+        (unsigned int) -1,
+        (unsigned int) -1,
+#endif
+#ifdef CONFIG_X86_64
+        PT_REGS_OFFSET(PERF_REG_X86_R8, r8),
+        PT_REGS_OFFSET(PERF_REG_X86_R9, r9),
+        PT_REGS_OFFSET(PERF_REG_X86_R10, r10),
+        PT_REGS_OFFSET(PERF_REG_X86_R11, r11),
+        PT_REGS_OFFSET(PERF_REG_X86_R12, r12),
+        PT_REGS_OFFSET(PERF_REG_X86_R13, r13),
+        PT_REGS_OFFSET(PERF_REG_X86_R14, r14),
+        PT_REGS_OFFSET(PERF_REG_X86_R15, r15),
+#endif
+};
+
+u64 perf_reg_value(struct pt_regs *regs, int idx)
+{
+        if (WARN_ON_ONCE(idx >= ARRAY_SIZE(pt_regs_offset)))
+                return 0;
+
+        return regs_get_register(regs, pt_regs_offset[idx]);
+}
+
+#define REG_RESERVED (~((1ULL << PERF_REG_X86_MAX) - 1ULL))
+
+#ifdef CONFIG_X86_32
+int perf_reg_validate(u64 mask)
+{
+        if (!mask || mask & REG_RESERVED)
+                return -EINVAL;
+
+        return 0;
+}
+
+u64 perf_reg_abi(struct task_struct *task)
+{
+        return PERF_SAMPLE_REGS_ABI_32;
+}
+#else /* CONFIG_X86_64 */
+#define REG_NOSUPPORT ((1ULL << PERF_REG_X86_DS) | \
+                       (1ULL << PERF_REG_X86_ES) | \
+                       (1ULL << PERF_REG_X86_FS) | \
+                       (1ULL << PERF_REG_X86_GS))
+
+int perf_reg_validate(u64 mask)
+{
+        if (!mask || mask & REG_RESERVED)
+                return -EINVAL;
+
+        if (mask & REG_NOSUPPORT)
+                return -EINVAL;
+
+        return 0;
+}
+
+u64 perf_reg_abi(struct task_struct *task)
+{
+        if (test_tsk_thread_flag(task, TIF_IA32))
+                return PERF_SAMPLE_REGS_ABI_32;
+        else
+                return PERF_SAMPLE_REGS_ABI_64;
+}
+#endif /* CONFIG_X86_32 */