[PATCH v11 04/27] powerpc/ptrace: Enable support for NT_PPC_CGPR

wei.guo.simon
2016-07-17T02:01:28Z

This patch enables support for TM checkpointed GPR register
set ELF core note NT_PPC_CGPR based ptrace requests through
PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved
through adding a register set REGSET_CGPR 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/kernel/ptrace.c | 222 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 222 insertions(+)

diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 38df7f0..0334c23 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -181,6 +181,26 @@ static int set_user_msr(struct task_struct *task, unsigned long msr)
return 0;
}

+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+static unsigned long get_user_ckpt_msr(struct task_struct *task)
+{
+ return task->thread.ckpt_regs.msr | task->thread.fpexc_mode;
+}
+
+static int set_user_ckpt_msr(struct task_struct *task, unsigned long msr)
+{
+ task->thread.ckpt_regs.msr &= ~MSR_DEBUGCHANGE;
+ task->thread.ckpt_regs.msr |= msr & MSR_DEBUGCHANGE;
+ return 0;
+}
+
+static int set_user_ckpt_trap(struct task_struct *task, unsigned long trap)
+{
+ task->thread.ckpt_regs.trap = trap & 0xfff0;
+ return 0;
+}
+#endif
+
#ifdef CONFIG_PPC64
static int get_user_dscr(struct task_struct *task, unsigned long *data)
{
@@ -614,6 +634,172 @@ static int evr_set(struct task_struct *target, const struct user_regset *regset,
}
#endif /* CONFIG_SPE */

+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+/**
+ * tm_cgpr_active - get active number of registers in CGPR
+ * @target: The target task.
+ * @regset: The user regset structure.
+ *
+ * This function checks for the active number of available
+ * regisers in transaction checkpointed GPR category.
+ */
+static int tm_cgpr_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;
+
+ return regset->n;
+}
+
+/**
+ * tm_cgpr_get - get CGPR 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 transaction checkpointed GPR registers.
+ *
+ * When the transaction is active, 'ckpt_regs' holds all the checkpointed
+ * GPR register values for the current transaction to fall back on if it
+ * aborts in between. This function gets those checkpointed GPR registers.
+ * The userspace interface buffer layout is as follows.
+ *
+ * struct data {
+ * struct pt_regs ckpt_regs;
+ * };
+ */
+static int tm_cgpr_get(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf)
+{
+ int ret;
+
+ if (!cpu_has_feature(CPU_FTR_TM))
+ return -ENODEV;
+
+ if (!MSR_TM_ACTIVE(target->thread.regs->msr))
+ return -ENODATA;
+
+ flush_fp_to_thread(target);
+ flush_altivec_to_thread(target);
+ flush_tmregs_to_thread(target);
+
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.ckpt_regs,
+ 0, offsetof(struct pt_regs, msr));
+ if (!ret) {
+ unsigned long msr = get_user_ckpt_msr(target);
+
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &msr,
+ offsetof(struct pt_regs, msr),
+ offsetof(struct pt_regs, msr) +
+ sizeof(msr));
+ }
+
+ BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
+ offsetof(struct pt_regs, msr) + sizeof(long));
+
+ if (!ret)
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.ckpt_regs.orig_gpr3,
+ offsetof(struct pt_regs, orig_gpr3),
+ sizeof(struct pt_regs));
+ if (!ret)
+ ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
+ sizeof(struct pt_regs), -1);
+
+ return ret;
+}
+
+/*
+ * tm_cgpr_set - set the CGPR 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 GPR registers.
+ *
+ * When the transaction is active, 'ckpt_regs' holds the checkpointed
+ * GPR register values for the current transaction to fall back on if it
+ * aborts in between. This function sets those checkpointed GPR registers.
+ * The userspace interface buffer layout is as follows.
+ *
+ * struct data {
+ * struct pt_regs ckpt_regs;
+ * };
+ */
+static int tm_cgpr_set(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ unsigned long reg;
+ int ret;
+
+ if (!cpu_has_feature(CPU_FTR_TM))
+ return -ENODEV;
+
+ if (!MSR_TM_ACTIVE(target->thread.regs->msr))
+ return -ENODATA;
+
+ flush_fp_to_thread(target);
+ flush_altivec_to_thread(target);
+ flush_tmregs_to_thread(target);
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.ckpt_regs,
+ 0, PT_MSR * sizeof(reg));
+
+ if (!ret && count > 0) {
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &reg,
+ PT_MSR * sizeof(reg),
+ (PT_MSR + 1) * sizeof(reg));
+ if (!ret)
+ ret = set_user_ckpt_msr(target, reg);
+ }
+
+ BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
+ offsetof(struct pt_regs, msr) + sizeof(long));
+
+ if (!ret)
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.ckpt_regs.orig_gpr3,
+ PT_ORIG_R3 * sizeof(reg),
+ (PT_MAX_PUT_REG + 1) * sizeof(reg));
+
+ if (PT_MAX_PUT_REG + 1 < PT_TRAP && !ret)
+ ret = user_regset_copyin_ignore(
+ &pos, &count, &kbuf, &ubuf,
+ (PT_MAX_PUT_REG + 1) * sizeof(reg),
+ PT_TRAP * sizeof(reg));
+
+ if (!ret && count > 0) {
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &reg,
+ PT_TRAP * sizeof(reg),
+ (PT_TRAP + 1) * sizeof(reg));
+ if (!ret)
+ ret = set_user_ckpt_trap(target, reg);
+ }
+
+ if (!ret)
+ ret = user_regset_copyin_ignore(
+ &pos, &count, &kbuf, &ubuf,
+ (PT_TRAP + 1) * sizeof(reg), -1);
+
+ return ret;
+}
+#endif

/*
* These are our native regset flavors.
@@ -630,6 +816,9 @@ enum powerpc_regset {
#ifdef CONFIG_SPE
REGSET_SPE,
#endif
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+ REGSET_TM_CGPR, /* TM checkpointed GPR registers */
+#endif
};

static const struct user_regset native_regsets[] = {
@@ -664,6 +853,13 @@ static const struct user_regset native_regsets[] = {
.active = evr_active, .get = evr_get, .set = evr_set
},
#endif
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+ [REGSET_TM_CGPR] = {
+ .core_note_type = NT_PPC_TM_CGPR, .n = ELF_NGREG,
+ .size = sizeof(long), .align = sizeof(long),
+ .active = tm_cgpr_active, .get = tm_cgpr_get, .set = tm_cgpr_set
+ },
+#endif
};

static const struct user_regset_view user_ppc_native_view = {
@@ -826,6 +1022,24 @@ static int gpr32_set_common(struct task_struct *target,
(PT_TRAP + 1) * sizeof(reg), -1);
}

+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+static int tm_cgpr32_get(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf)
+{
+ return gpr32_get_common(target, regset, pos, count, kbuf, ubuf, 1);
+}
+
+static int tm_cgpr32_set(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ return gpr32_set_common(target, regset, pos, count, kbuf, ubuf, 1);
+}
+#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+
static int gpr32_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
@@ -870,6 +1084,14 @@ static const struct user_regset compat_regsets[] = {
.active = evr_active, .get = evr_get, .set = evr_set
},
#endif
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+ [REGSET_TM_CGPR] = {
+ .core_note_type = NT_PPC_TM_CGPR, .n = ELF_NGREG,
+ .size = sizeof(long), .align = sizeof(long),
+ .active = tm_cgpr_active,
+ .get = tm_cgpr32_get, .set = tm_cgpr32_set
+ },
+#endif
};

static const struct user_regset_view user_ppc_compat_view = {
--
1.8.3.1