[PATCH v11 11/27] powerpc/ptrace: Enable support for EBB registers

wei.guo.simon
2016-07-17T02:02:20Z

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.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Cyril Bur <cyrilbur@gmail.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Simon Guo <wei.guo.simon@gmail.com>
Cc: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Rashmica Gupta <rashmicy@gmail.com>
Cc: Khem Raj <raj.khem@gmail.com>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Cc: Chris Smart <chris@distroguy.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
---
arch/powerpc/include/uapi/asm/elf.h | 1 +
arch/powerpc/kernel/ptrace.c | 75 +++++++++++++++++++++++++++++++++++++
2 files changed, 76 insertions(+)

diff --git a/arch/powerpc/include/uapi/asm/elf.h b/arch/powerpc/include/uapi/asm/elf.h
index e703c64..8c4d71a 100644
--- a/arch/powerpc/include/uapi/asm/elf.h
+++ b/arch/powerpc/include/uapi/asm/elf.h
@@ -94,6 +94,7 @@
#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 3 /* includes ebbrr, ebbhr, bescr */

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 1a091db..52c69ed 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -1527,6 +1527,70 @@ 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)
+{
+ /* Build tests */
+ BUILD_BUG_ON(TSO(ebbrr) + sizeof(unsigned long) != TSO(ebbhr));
+ BUILD_BUG_ON(TSO(ebbhr) + sizeof(unsigned long) != TSO(bescr));
+
+ if (!cpu_has_feature(CPU_FTR_ARCH_207S))
+ return -ENODEV;
+
+ if (!target->thread.used_ebb)
+ return -ENODATA;
+
+ return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.ebbrr, 0, 3 * sizeof(unsigned long));
+}
+
+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));
+
+ 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));
+
+ return ret;
+}
#endif
/*
* These are our native regset flavors.
@@ -1559,6 +1623,7 @@ enum powerpc_regset {
#endif
#ifdef CONFIG_PPC_BOOK3S_64
REGSET_TAR, /* TAR register */
+ REGSET_EBB, /* EBB registers */
#endif
};

@@ -1654,6 +1719,11 @@ 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
};

@@ -1940,6 +2010,11 @@ 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
};

--
1.8.3.1