diff mbox series

[v8,22/28] arm64: mte: ptrace: Add NT_ARM_TAGGED_ADDR_CTRL regset

Message ID 20200824182758.27267-23-catalin.marinas@arm.com (mailing list archive)
State New, archived
Headers show
Series arm64: Memory Tagging Extension user-space support | expand

Commit Message

Catalin Marinas Aug. 24, 2020, 6:27 p.m. UTC 
This regset allows read/write access to a ptraced process
prctl(PR_SET_TAGGED_ADDR_CTRL) setting.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Alan Hayward <Alan.Hayward@arm.com>
Cc: Luis Machado <luis.machado@linaro.org>
Cc: Omair Javaid <omair.javaid@linaro.org>
---

Notes:
    v8:
    - Removed user_regset_copyout().
    
    New in v7.

 arch/arm64/kernel/ptrace.c | 42 ++++++++++++++++++++++++++++++++++++++
 include/uapi/linux/elf.h   |  1 +
 2 files changed, 43 insertions(+)
diff mbox series

Patch

diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 101040a37d40..f49b349e16a3 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -1033,6 +1033,35 @@  static int pac_generic_keys_set(struct task_struct *target,
 #endif /* CONFIG_CHECKPOINT_RESTORE */
 #endif /* CONFIG_ARM64_PTR_AUTH */
 
+#ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
+static int tagged_addr_ctrl_get(struct task_struct *target,
+				const struct user_regset *regset,
+				struct membuf to)
+{
+	long ctrl = get_tagged_addr_ctrl(target);
+
+	if (IS_ERR_VALUE(ctrl))
+		return ctrl;
+
+	return membuf_write(&to, &ctrl, sizeof(ctrl));
+}
+
+static int tagged_addr_ctrl_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;
+	long ctrl;
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl, 0, -1);
+	if (ret)
+		return ret;
+
+	return set_tagged_addr_ctrl(target, ctrl);
+}
+#endif
+
 enum aarch64_regset {
 	REGSET_GPR,
 	REGSET_FPR,
@@ -1052,6 +1081,9 @@  enum aarch64_regset {
 	REGSET_PACG_KEYS,
 #endif
 #endif
+#ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
+	REGSET_TAGGED_ADDR_CTRL,
+#endif
 };
 
 static const struct user_regset aarch64_regsets[] = {
@@ -1149,6 +1181,16 @@  static const struct user_regset aarch64_regsets[] = {
 	},
 #endif
 #endif
+#ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
+	[REGSET_TAGGED_ADDR_CTRL] = {
+		.core_note_type = NT_ARM_TAGGED_ADDR_CTRL,
+		.n = 1,
+		.size = sizeof(long),
+		.align = sizeof(long),
+		.regset_get = tagged_addr_ctrl_get,
+		.set = tagged_addr_ctrl_set,
+	},
+#endif
 };
 
 static const struct user_regset_view user_aarch64_view = {
diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h
index 22220945a5fd..30f68b42eeb5 100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -425,6 +425,7 @@  typedef struct elf64_shdr {
 #define NT_ARM_PAC_MASK		0x406	/* ARM pointer authentication code masks */
 #define NT_ARM_PACA_KEYS	0x407	/* ARM pointer authentication address keys */
 #define NT_ARM_PACG_KEYS	0x408	/* ARM pointer authentication generic key */
+#define NT_ARM_TAGGED_ADDR_CTRL	0x409	/* arm64 tagged address control (prctl()) */
 #define NT_ARC_V2	0x600		/* ARCv2 accumulator/extra registers */
 #define NT_VMCOREDD	0x700		/* Vmcore Device Dump Note */
 #define NT_MIPS_DSP	0x800		/* MIPS DSP ASE registers */