[PATCH v11 07/27] powerpc/ptrace: Enable support for NT_PPC_CVSX

wei.guo.simon
2016-07-17T02:01:51Z

This patch enables support for TM checkpointed VSX register
set ELF core note NT_PPC_CVSX based ptrace requests through
PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved
through adding a register set REGSET_CVSX 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>
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
---
arch/powerpc/include/uapi/asm/elf.h | 1 +
arch/powerpc/kernel/ptrace.c | 129 ++++++++++++++++++++++++++++++++++++
2 files changed, 130 insertions(+)

diff --git a/arch/powerpc/include/uapi/asm/elf.h b/arch/powerpc/include/uapi/asm/elf.h
index ecb4e84..1549172 100644
--- a/arch/powerpc/include/uapi/asm/elf.h
+++ b/arch/powerpc/include/uapi/asm/elf.h
@@ -92,6 +92,7 @@
#define ELF_NGREG 48 /* includes nip, msr, lr, etc. */
#define ELF_NFPREG 33 /* includes fpscr */
#define ELF_NVMX 34 /* includes all vector registers */
+#define ELF_NVSX 32 /* includes all VSX registers */

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 a2cf240..a824e491 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -65,6 +65,7 @@ struct pt_regs_offset {
#define REG_OFFSET_END {.name = NULL, .offset = 0}

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

static const struct pt_regs_offset regoffset_table[] = {
GPR_OFFSET_NAME(0),
@@ -1061,6 +1062,123 @@ static int tm_cvmx_set(struct task_struct *target,

return ret;
}
+
+/**
+ * tm_cvsx_active - get active number of registers in CVSX
+ * @target: The target task.
+ * @regset: The user regset structure.
+ *
+ * This function checks for the active number of available
+ * regisers in transaction checkpointed VSX category.
+ */
+static int tm_cvsx_active(struct task_struct *target,
+ const struct user_regset *regset)
+{
+ if (!cpu_has_feature(CPU_FTR_TM))
+ return -ENODEV;
+
+ if (!MSR_TM_ACTIVE(target->thread.regs->msr))
+ return 0;
+
+ flush_vsx_to_thread(target);
+ return target->thread.used_vsr ? regset->n : 0;
+}
+
+/**
+ * tm_cvsx_get - get CVSX 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 in transaction checkpointed VSX registers.
+ *
+ * When the transaction is active 'ckfp_state' holds the checkpointed
+ * values for the current transaction to fall back on if it aborts
+ * in between. This function gets those checkpointed VSX registers.
+ * The userspace interface buffer layout is as follows.
+ *
+ * struct data {
+ * u64 vsx[32];
+ *};
+ */
+static int tm_cvsx_get(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf)
+{
+ u64 buf[32];
+ int ret, i;
+
+ if (!cpu_has_feature(CPU_FTR_TM))
+ return -ENODEV;
+
+ if (!MSR_TM_ACTIVE(target->thread.regs->msr))
+ return -ENODATA;
+
+ /* Flush the state */
+ flush_fp_to_thread(target);
+ flush_altivec_to_thread(target);
+ flush_tmregs_to_thread(target);
+ flush_vsx_to_thread(target);
+
+ for (i = 0; i < 32 ; i++)
+ buf[i] = target->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET];
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ buf, 0, 32 * sizeof(double));
+
+ return ret;
+}
+
+/**
+ * tm_cvsx_set - set CFPR 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 in transaction checkpointed VSX registers.
+ *
+ * When the transaction is active 'fp_state' holds the checkpointed
+ * VSX register values for the current transaction to fall back on
+ * if it aborts in between. This function sets these checkpointed
+ * FPR registers. The userspace interface buffer layout is as follows.
+ *
+ * struct data {
+ * u64 vsx[32];
+ *};
+ */
+static int tm_cvsx_set(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ u64 buf[32];
+ int ret, i;
+
+ if (!cpu_has_feature(CPU_FTR_TM))
+ return -ENODEV;
+
+ if (!MSR_TM_ACTIVE(target->thread.regs->msr))
+ return -ENODATA;
+
+ /* Flush the state */
+ flush_fp_to_thread(target);
+ flush_altivec_to_thread(target);
+ flush_tmregs_to_thread(target);
+ flush_vsx_to_thread(target);
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ buf, 0, 32 * sizeof(double));
+ for (i = 0; i < 32 ; i++)
+ target->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = buf[i];
+
+ return ret;
+}
#endif

/*
@@ -1082,6 +1200,7 @@ enum powerpc_regset {
REGSET_TM_CGPR, /* TM checkpointed GPR registers */
REGSET_TM_CFPR, /* TM checkpointed FPR registers */
REGSET_TM_CVMX, /* TM checkpointed VMX registers */
+ REGSET_TM_CVSX, /* TM checkpointed VSX registers */
#endif
};

@@ -1133,6 +1252,11 @@ static const struct user_regset native_regsets[] = {
.size = sizeof(vector128), .align = sizeof(vector128),
.active = tm_cvmx_active, .get = tm_cvmx_get, .set = tm_cvmx_set
},
+ [REGSET_TM_CVSX] = {
+ .core_note_type = NT_PPC_TM_CVSX, .n = ELF_NVSX,
+ .size = sizeof(double), .align = sizeof(double),
+ .active = tm_cvsx_active, .get = tm_cvsx_get, .set = tm_cvsx_set
+ },
#endif
};

@@ -1375,6 +1499,11 @@ static const struct user_regset compat_regsets[] = {
.size = sizeof(vector128), .align = sizeof(vector128),
.active = tm_cvmx_active, .get = tm_cvmx_get, .set = tm_cvmx_set
},
+ [REGSET_TM_CVSX] = {
+ .core_note_type = NT_PPC_TM_CVSX, .n = ELF_NVSX,
+ .size = sizeof(double), .align = sizeof(double),
+ .active = tm_cvsx_active, .get = tm_cvsx_get, .set = tm_cvsx_set
+ },
#endif
};

--
1.8.3.1