[PATCH V9 14/28] powerpc, ptrace: Enable support for EBB registers

From: Anshuman Khandual
Date: Thu Oct 08 2015 - 10:50:21 EST


This patch enables support for EBB state registers related
ELF core note NT_PPC_EBB based ptrace requests through
PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved
through adding one new register sets REGSET_EBB 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@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/uapi/asm/elf.h | 3 +
arch/powerpc/kernel/ptrace.c | 147 ++++++++++++++++++++++++++++++++++++
2 files changed, 150 insertions(+)

diff --git a/arch/powerpc/include/uapi/asm/elf.h b/arch/powerpc/include/uapi/asm/elf.h
index 9e6b6e3..b849a70 100644
--- a/arch/powerpc/include/uapi/asm/elf.h
+++ b/arch/powerpc/include/uapi/asm/elf.h
@@ -94,6 +94,9 @@
#define ELF_NVMX 34 /* includes all vector registers */
#define ELF_NVSX 32 /* includes all VSX registers */
#define ELF_NTMSPRREG 3 /* include tfhar, tfiar, texasr */
+#define ELF_NEBB 8 /* includes ebbrr, ebbhr, bescr, siar,
+ * sdar, sier, mmcr2, mmcr0
+ */

typedef unsigned long elf_greg_t64;
typedef elf_greg_t64 elf_gregset_t64[ELF_NGREG];
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 44aedfb..b04df17 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -1759,6 +1759,142 @@ static int tar_set(struct task_struct *target,
&target->thread.tar, 0, sizeof(u64));
return ret;
}
+
+static int ebb_active(struct task_struct *target,
+ const struct user_regset *regset)
+{
+ if (!cpu_has_feature(CPU_FTR_ARCH_207S))
+ return -ENODEV;
+
+ if (target->thread.used_ebb)
+ return regset->n;
+
+ return 0;
+}
+
+static int ebb_get(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf)
+{
+ int ret;
+
+ /* Build tests */
+ BUILD_BUG_ON(TSO(ebbrr) + sizeof(unsigned long) != TSO(ebbhr));
+ BUILD_BUG_ON(TSO(ebbhr) + sizeof(unsigned long) != TSO(bescr));
+ BUILD_BUG_ON(TSO(bescr) + sizeof(unsigned long) != TSO(siar));
+ 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;
+
+ if (!target->thread.used_ebb)
+ return -ENODATA;
+
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.ebbrr, 0, sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.ebbhr, sizeof(unsigned long),
+ 2 * sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.bescr,
+ 2 * sizeof(unsigned long), 3 * sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.siar, 3 * sizeof(unsigned long),
+ 4 * sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.sdar, 4 * sizeof(unsigned long),
+ 5 * sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.sier, 5 * sizeof(unsigned long),
+ 6 * sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.mmcr2, 6 * sizeof(unsigned long),
+ 7 * sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.mmcr0, 7 * sizeof(unsigned long),
+ 8 * sizeof(unsigned long));
+ return ret;
+}
+
+static int ebb_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(ebbrr) + sizeof(unsigned long) != TSO(ebbhr));
+ BUILD_BUG_ON(TSO(ebbhr) + sizeof(unsigned long) != TSO(bescr));
+ BUILD_BUG_ON(TSO(bescr) + sizeof(unsigned long) != TSO(siar));
+ 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;
+
+ if (target->thread.used_ebb)
+ return -ENODATA;
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.ebbrr, 0, sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.ebbhr, sizeof(unsigned long),
+ 2 * sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.bescr,
+ 2 * sizeof(unsigned long), 3 * sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.siar, 3 * sizeof(unsigned long),
+ 4 * sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.sdar, 4 * sizeof(unsigned long),
+ 5 * sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.sier, 5 * sizeof(unsigned long),
+ 6 * sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.mmcr2, 6 * sizeof(unsigned long),
+ 7 * sizeof(unsigned long));
+
+ if (!ret)
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.mmcr0, 7 * sizeof(unsigned long),
+ 8 * sizeof(unsigned long));
+ return ret;
+}
#endif
/*
* These are our native regset flavors.
@@ -1791,6 +1927,7 @@ enum powerpc_regset {
#endif
#ifdef CONFIG_PPC_BOOK3S_64
REGSET_TAR, /* TAR register */
+ REGSET_EBB, /* EBB registers */
#endif
};

@@ -1886,6 +2023,11 @@ static const struct user_regset native_regsets[] = {
.size = sizeof(u64), .align = sizeof(u64),
.get = tar_get, .set = tar_set
},
+ [REGSET_EBB] = {
+ .core_note_type = NT_PPC_EBB, .n = ELF_NEBB,
+ .size = sizeof(u64), .align = sizeof(u64),
+ .active = ebb_active, .get = ebb_get, .set = ebb_set
+ },
#endif
};

@@ -2172,6 +2314,11 @@ static const struct user_regset compat_regsets[] = {
.size = sizeof(u64), .align = sizeof(u64),
.get = tar_get, .set = tar_set
},
+ [REGSET_EBB] = {
+ .core_note_type = NT_PPC_EBB, .n = ELF_NEBB,
+ .size = sizeof(u64), .align = sizeof(u64),
+ .active = ebb_active, .get = ebb_get, .set = ebb_set
+ },
#endif
};

--
2.1.0

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