[PATCH v11 08/27] powerpc/ptrace: Enable support for TM SPR state

wei.guo.simon
2016-07-17T02:02:00Z

This patch enables support for TM SPR state related ELF core
note NT_PPC_TM_SPR based ptrace requests through PTRACE_GETREGSET,
PTRACE_SETREGSET calls. This is achieved through adding a register
set REGSET_TM_SPR in powerpc corresponding to the ELF core note
section added. It implements the get, set and active functions for
this new register set 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>
---
arch/powerpc/include/uapi/asm/elf.h | 1 +
arch/powerpc/kernel/ptrace.c | 143 +++++++++++++++++++++++++++++++++++-
2 files changed, 143 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/uapi/asm/elf.h b/arch/powerpc/include/uapi/asm/elf.h
index 1549172..e703c64 100644
--- a/arch/powerpc/include/uapi/asm/elf.h
+++ b/arch/powerpc/include/uapi/asm/elf.h
@@ -93,6 +93,7 @@
#define ELF_NFPREG 33 /* includes fpscr */
#define ELF_NVMX 34 /* includes all vector registers */
#define ELF_NVSX 32 /* includes all VSX registers */
+#define ELF_NTMSPRREG 3 /* include tfhar, tfiar, texasr */

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 a824e491..66bb46a 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -66,6 +66,7 @@ struct pt_regs_offset {

#define TVSO(f) (offsetof(struct thread_vr_state, f))
#define TFSO(f) (offsetof(struct thread_fp_state, f))
+#define TSO(f) (offsetof(struct thread_struct, f))

static const struct pt_regs_offset regoffset_table[] = {
GPR_OFFSET_NAME(0),
@@ -1179,7 +1180,136 @@ static int tm_cvsx_set(struct task_struct *target,

return ret;
}
-#endif
+
+/**
+ * tm_spr_active - get active number of registers in TM SPR
+ * @target: The target task.
+ * @regset: The user regset structure.
+ *
+ * This function checks the active number of available
+ * regisers in the transactional memory SPR category.
+ */
+static int tm_spr_active(struct task_struct *target,
+ const struct user_regset *regset)
+{
+ if (!cpu_has_feature(CPU_FTR_TM))
+ return -ENODEV;
+
+ return regset->n;
+}
+
+/**
+ * tm_spr_get - get the TM related SPR registers
+ * @target: The target task.
+ * @regset: The user regset structure.
+ * @pos: The buffer position.
+ * @count: Number of bytes to copy.
+ * @kbuf: Kernel buffer to copy from.
+ * @ubuf: User buffer to copy into.
+ *
+ * This function gets transactional memory related SPR registers.
+ * The userspace interface buffer layout is as follows.
+ *
+ * struct {
+ * u64 tm_tfhar;
+ * u64 tm_texasr;
+ * u64 tm_tfiar;
+ * };
+ */
+static int tm_spr_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(tm_tfhar) + sizeof(u64) != TSO(tm_texasr));
+ BUILD_BUG_ON(TSO(tm_texasr) + sizeof(u64) != TSO(tm_tfiar));
+ BUILD_BUG_ON(TSO(tm_tfiar) + sizeof(u64) != TSO(ckpt_regs));
+
+ if (!cpu_has_feature(CPU_FTR_TM))
+ return -ENODEV;
+
+ /* Flush the states */
+ flush_fp_to_thread(target);
+ flush_altivec_to_thread(target);
+ flush_tmregs_to_thread(target);
+
+ /* TFHAR register */
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.tm_tfhar, 0, sizeof(u64));
+
+ /* TEXASR register */
+ if (!ret)
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.tm_texasr, sizeof(u64),
+ 2 * sizeof(u64));
+
+ /* TFIAR register */
+ if (!ret)
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.tm_tfiar,
+ 2 * sizeof(u64), 3 * sizeof(u64));
+ return ret;
+}
+
+/**
+ * tm_spr_set - set the TM related SPR registers
+ * @target: The target task.
+ * @regset: The user regset structure.
+ * @pos: The buffer position.
+ * @count: Number of bytes to copy.
+ * @kbuf: Kernel buffer to copy into.
+ * @ubuf: User buffer to copy from.
+ *
+ * This function sets transactional memory related SPR registers.
+ * The userspace interface buffer layout is as follows.
+ *
+ * struct {
+ * u64 tm_tfhar;
+ * u64 tm_texasr;
+ * u64 tm_tfiar;
+ * };
+ */
+static int tm_spr_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;
+
+ /* Build tests */
+ BUILD_BUG_ON(TSO(tm_tfhar) + sizeof(u64) != TSO(tm_texasr));
+ BUILD_BUG_ON(TSO(tm_texasr) + sizeof(u64) != TSO(tm_tfiar));
+ BUILD_BUG_ON(TSO(tm_tfiar) + sizeof(u64) != TSO(ckpt_regs));
+
+ if (!cpu_has_feature(CPU_FTR_TM))
+ return -ENODEV;
+
+ /* Flush the states */
+ flush_fp_to_thread(target);
+ flush_altivec_to_thread(target);
+ flush_tmregs_to_thread(target);
+
+ /* TFHAR register */
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.tm_tfhar, 0, sizeof(u64));
+
+ /* TEXASR register */
+ if (!ret)
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.tm_texasr, sizeof(u64),
+ 2 * sizeof(u64));
+
+ /* TFIAR register */
+ if (!ret)
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.tm_tfiar,
+ 2 * sizeof(u64), 3 * sizeof(u64));
+ return ret;
+}
+#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */

/*
* These are our native regset flavors.
@@ -1201,6 +1331,7 @@ enum powerpc_regset {
REGSET_TM_CFPR, /* TM checkpointed FPR registers */
REGSET_TM_CVMX, /* TM checkpointed VMX registers */
REGSET_TM_CVSX, /* TM checkpointed VSX registers */
+ REGSET_TM_SPR, /* TM specific SPR registers */
#endif
};

@@ -1257,6 +1388,11 @@ static const struct user_regset native_regsets[] = {
.size = sizeof(double), .align = sizeof(double),
.active = tm_cvsx_active, .get = tm_cvsx_get, .set = tm_cvsx_set
},
+ [REGSET_TM_SPR] = {
+ .core_note_type = NT_PPC_TM_SPR, .n = ELF_NTMSPRREG,
+ .size = sizeof(u64), .align = sizeof(u64),
+ .active = tm_spr_active, .get = tm_spr_get, .set = tm_spr_set
+ },
#endif
};

@@ -1504,6 +1640,11 @@ static const struct user_regset compat_regsets[] = {
.size = sizeof(double), .align = sizeof(double),
.active = tm_cvsx_active, .get = tm_cvsx_get, .set = tm_cvsx_set
},
+ [REGSET_TM_SPR] = {
+ .core_note_type = NT_PPC_TM_SPR, .n = ELF_NTMSPRREG,
+ .size = sizeof(u64), .align = sizeof(u64),
+ .active = tm_spr_active, .get = tm_spr_get, .set = tm_spr_set
+ },
#endif
};

--
1.8.3.1