powerpc/ptrace: Enable support for Performance Monitor registers
This patch enables support for Performance monitor registers related
ELF core note NT_PPC_PMU based ptrace requests through
PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved
through adding one new register sets REGSET_PMU in powerpc
corresponding to the ELF core note sections added in this
regard. It also implements the get, set and active functions
for this new register sets added.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 7942f9c..4f3c575 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -1824,6 +1824,75 @@
return ret;
}
+static int pmu_active(struct task_struct *target,
+ const struct user_regset *regset)
+{
+ if (!cpu_has_feature(CPU_FTR_ARCH_207S))
+ return -ENODEV;
+
+ return regset->n;
+}
+
+static int pmu_get(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf)
+{
+ /* Build tests */
+ BUILD_BUG_ON(TSO(siar) + sizeof(unsigned long) != TSO(sdar));
+ BUILD_BUG_ON(TSO(sdar) + sizeof(unsigned long) != TSO(sier));
+ BUILD_BUG_ON(TSO(sier) + sizeof(unsigned long) != TSO(mmcr2));
+ BUILD_BUG_ON(TSO(mmcr2) + sizeof(unsigned long) != TSO(mmcr0));
+
+ if (!cpu_has_feature(CPU_FTR_ARCH_207S))
+ return -ENODEV;
+
+ return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.siar, 0,
+ 5 * sizeof(unsigned long));
+}
+
+static int pmu_set(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ int ret = 0;
+
+ /* Build tests */
+ BUILD_BUG_ON(TSO(siar) + sizeof(unsigned long) != TSO(sdar));
+ BUILD_BUG_ON(TSO(sdar) + sizeof(unsigned long) != TSO(sier));
+ BUILD_BUG_ON(TSO(sier) + sizeof(unsigned long) != TSO(mmcr2));
+ BUILD_BUG_ON(TSO(mmcr2) + sizeof(unsigned long) != TSO(mmcr0));
+
+ if (!cpu_has_feature(CPU_FTR_ARCH_207S))
+ return -ENODEV;
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.siar, 0,
+ sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.sdar, sizeof(unsigned long),
+ 2 * sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.sier, 2 * sizeof(unsigned long),
+ 3 * sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.mmcr2, 3 * sizeof(unsigned long),
+ 4 * sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.mmcr0, 4 * sizeof(unsigned long),
+ 5 * sizeof(unsigned long));
+ return ret;
+}
#endif
/*
* These are our native regset flavors.
@@ -1857,6 +1926,7 @@
#ifdef CONFIG_PPC_BOOK3S_64
REGSET_TAR, /* TAR register */
REGSET_EBB, /* EBB registers */
+ REGSET_PMR, /* Performance Monitor Registers */
#endif
};
@@ -1957,6 +2027,11 @@
.size = sizeof(u64), .align = sizeof(u64),
.active = ebb_active, .get = ebb_get, .set = ebb_set
},
+ [REGSET_PMR] = {
+ .core_note_type = NT_PPC_PMU, .n = ELF_NPMU,
+ .size = sizeof(u64), .align = sizeof(u64),
+ .active = pmu_active, .get = pmu_get, .set = pmu_set
+ },
#endif
};