This patch enables get and set of miscellaneous debug registers through
ptrace PTRACE_GETREGSET-PTRACE_SETREGSET interface by implementing new
powerpc specific register set REGSET_MISC support corresponding to the
new ELF core note NT_PPC_MISC added previously in this regard.
Signed-off-by: Anshuman Khandual <khand...@linux.vnet.ibm.com>
---
arch/powerpc/include/uapi/asm/elf.h | 1 +
arch/powerpc/kernel/ptrace.c | 102 ++++++++++++++++++++++++++++++++++++
2 files changed, 103 insertions(+)
diff --git a/arch/powerpc/include/uapi/asm/elf.h
b/arch/powerpc/include/uapi/asm/elf.h
index fdc8e2f..a41bd98 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_NTMSPRREG 7 /* includes TM sprs, org_msr, dscr, tar, ppr */
+#define ELF_NMISCREG 3 /* includes dscr, tar, ppr */
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 b279947..61a2581 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -1327,6 +1327,97 @@ static int tm_cvmx_set(struct task_struct *target,
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
/*
+ * get_misc_dbg
+ *
+ * This function gets miscellaneous debug registers
+ * which includes DSCR, PPR and TAR.
+ *
+ * Userspace intarface buffer layout:
+ *
+ * struct {
+ * unsigned long dscr;
+ * unsigned long ppr;
+ * unsigned long tar;
+ * };
+ */
+static int get_misc_dbg(struct task_struct *target,
+ const struct user_regset *regset, unsigned int pos,
+ unsigned int count, void *kbuf, void __user *ubuf)
+{
+ int ret;
+
+ /* Build test */
+ BUILD_BUG_ON(TSO(dscr) + 2 * sizeof(unsigned long) != TSO(ppr));
+ BUILD_BUG_ON(TSO(ppr) + sizeof(unsigned long) != TSO(tar));
+
+ /* DSCR register */
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.dscr, 0,
+ sizeof(unsigned long));
+
+ /* PPR register */
+ if (!ret)
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.ppr,
+ sizeof(unsigned long),
+ 2 * sizeof(unsigned long));
+
+ /* TAR register */
+ if (!ret)
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.tar,
+ 2 * sizeof(unsigned long),
+ 3 * sizeof(unsigned long));
+ return ret;
+}
+
+/*
+ * set_misc_dbg
+ *
+ * This function sets miscellaneous debug registers
+ * which includes DSCR, PPR and TAR.
+ *
+ * Userspace intarface buffer layout:
+ *
+ * struct {
+ * unsigned long dscr;
+ * unsigned long ppr;
+ * unsigned long tar;
+ * };
+ */
+static int set_misc_dbg(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 test */
+ BUILD_BUG_ON(TSO(dscr) + 2 * sizeof(unsigned long) != TSO(ppr));
+ BUILD_BUG_ON(TSO(ppr) + sizeof(unsigned long) != TSO(tar));
+
+ /* DSCR register */
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.dscr, 0,
+ sizeof(unsigned long));
+
+ /* PPR register */
+ if (!ret)
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.ppr,
+ sizeof(unsigned long),
+ 2 * sizeof(unsigned long));
+
+ /* TAR register */
+ if (!ret)
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.tar,
+ 2 * sizeof(unsigned long),
+ 3 * sizeof(unsigned long));
+ return ret;
+}
+
+/*
* These are our native regset flavors.
*/
enum powerpc_regset {
@@ -1347,6 +1438,7 @@ enum powerpc_regset {
REGSET_TM_CFPR, /* TM checkpointed FPR registers */
REGSET_TM_CVMX, /* TM checkpointed VMX registers */
#endif
+ REGSET_MISC /* Miscellaneous debug registers */
};
static const struct user_regset native_regsets[] = {
@@ -1403,6 +1495,11 @@ static const struct user_regset native_regsets[] = {
.active = tm_cvmx_active, .get = tm_cvmx_get, .set = tm_cvmx_set
},
#endif
+ [REGSET_MISC] = {
+ .core_note_type = NT_PPC_MISC, .n = ELF_NMISCREG,
+ .size = sizeof(u64), .align = sizeof(u64),
+ .get = get_misc_dbg, .set = set_misc_dbg
+ },
};
static const struct user_regset_view user_ppc_native_view = {
@@ -1646,6 +1743,11 @@ static const struct user_regset compat_regsets[] = {
.active = tm_cvmx_active, .get = tm_cvmx_get, .set = tm_cvmx_set
},
#endif
+ [REGSET_MISC] = {
+ .core_note_type = NT_PPC_MISC, .n = ELF_NMISCREG,
+ .size = sizeof(u64), .align = sizeof(u64),
+ .get = get_misc_dbg, .set = set_misc_dbg
+ },
};
static const struct user_regset_view user_ppc_compat_view = {
--
1.9.3
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