Re: [PATCH v7 1/7] arm64: Add HAVE_REGS_AND_STACK_ACCESS_API feature
From: David Long
Date: Mon Jun 29 2015 - 14:37:22 EST
On 06/29/15 13:23, Steve Capper wrote:
On 15 June 2015 at 20:07, David Long <dave.long@xxxxxxxxxx> wrote:
From: "David A. Long" <dave.long@xxxxxxxxxx>
Add HAVE_REGS_AND_STACK_ACCESS_API feature for arm64.
Signed-off-by: David A. Long <dave.long@xxxxxxxxxx>
---
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/ptrace.h | 25 +++++++++++++
arch/arm64/kernel/ptrace.c | 77 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 103 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7796af4..966091f 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -68,6 +68,7 @@ config ARM64
select HAVE_PERF_EVENTS
select HAVE_PERF_REGS
select HAVE_PERF_USER_STACK_DUMP
+ select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_RCU_TABLE_FREE
select HAVE_SYSCALL_TRACEPOINTS
select IRQ_DOMAIN
diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index d6dd9fd..8f440e9 100644
--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -118,6 +118,8 @@ struct pt_regs {
u64 syscallno;
};
+#define MAX_REG_OFFSET (sizeof(struct user_pt_regs) - sizeof(u64))
+
#define arch_has_single_step() (1)
#ifdef CONFIG_COMPAT
@@ -146,6 +148,29 @@ struct pt_regs {
#define user_stack_pointer(regs) \
(!compat_user_mode(regs) ? (regs)->sp : (regs)->compat_sp)
+/**
+ * regs_get_register() - get register value from its offset
+ * @regs: pt_regs from which register value is gotten
+ * @offset: offset number of the register.
+ *
+ * regs_get_register returns the value of a register whose offset from @regs.
+ * The @offset is the offset of the register in struct pt_regs.
+ * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
+ */
+static inline u64 regs_get_register(struct pt_regs *regs,
+ unsigned int offset)
+{
+ if (unlikely(offset > MAX_REG_OFFSET))
+ return 0;
+ return *(u64 *)((u64)regs + offset);
Why not:
return regs->regs[offset];
This would not be correct. The offset is a byte offset and your code
would index eight times that amount into the structure. The offset
needs to remain a byte offset so architecture-independent code does not
need to know the architecture-specific layout of the structure.
+}
+
+/* Valid only for Kernel mode traps. */
+static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
+{
+ return regs->sp;
+}
+
static inline unsigned long regs_return_value(struct pt_regs *regs)
{
return regs->regs[0];
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index d882b83..f6199a5 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -48,6 +48,83 @@
#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>
+#define ARM_pstate pstate
+#define ARM_pc pc
+#define ARM_sp sp
+#define ARM_x30 regs[30]
+#define ARM_x29 regs[29]
+#define ARM_x28 regs[28]
+#define ARM_x27 regs[27]
+#define ARM_x26 regs[26]
+#define ARM_x25 regs[25]
+#define ARM_x24 regs[24]
+#define ARM_x23 regs[23]
+#define ARM_x22 regs[22]
+#define ARM_x21 regs[21]
+#define ARM_x20 regs[20]
+#define ARM_x19 regs[19]
+#define ARM_x18 regs[18]
+#define ARM_x17 regs[17]
+#define ARM_x16 regs[16]
+#define ARM_x15 regs[15]
+#define ARM_x14 regs[14]
+#define ARM_x13 regs[13]
+#define ARM_x12 regs[12]
+#define ARM_x11 regs[11]
+#define ARM_x10 regs[10]
+#define ARM_x9 regs[9]
+#define ARM_x8 regs[8]
+#define ARM_x7 regs[7]
+#define ARM_x6 regs[6]
+#define ARM_x5 regs[5]
+#define ARM_x4 regs[4]
+#define ARM_x3 regs[3]
+#define ARM_x2 regs[2]
+#define ARM_x1 regs[1]
+#define ARM_x0 regs[0]
+
+#define REG_OFFSET_NAME(r) \
+ {.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)}
+#define REG_OFFSET_END {.name = NULL, .offset = 0}
+
+const struct pt_regs_offset regs_offset_table[] = {
+ REG_OFFSET_NAME(x0),
+ REG_OFFSET_NAME(x1),
+ REG_OFFSET_NAME(x2),
+ REG_OFFSET_NAME(x3),
+ REG_OFFSET_NAME(x4),
+ REG_OFFSET_NAME(x5),
+ REG_OFFSET_NAME(x6),
+ REG_OFFSET_NAME(x7),
+ REG_OFFSET_NAME(x8),
+ REG_OFFSET_NAME(x9),
+ REG_OFFSET_NAME(x10),
+ REG_OFFSET_NAME(x11),
+ REG_OFFSET_NAME(x12),
+ REG_OFFSET_NAME(x13),
+ REG_OFFSET_NAME(x14),
+ REG_OFFSET_NAME(x15),
+ REG_OFFSET_NAME(x16),
+ REG_OFFSET_NAME(x17),
+ REG_OFFSET_NAME(x18),
+ REG_OFFSET_NAME(x19),
+ REG_OFFSET_NAME(x20),
+ REG_OFFSET_NAME(x21),
+ REG_OFFSET_NAME(x22),
+ REG_OFFSET_NAME(x23),
+ REG_OFFSET_NAME(x24),
+ REG_OFFSET_NAME(x25),
+ REG_OFFSET_NAME(x26),
+ REG_OFFSET_NAME(x27),
+ REG_OFFSET_NAME(x28),
+ REG_OFFSET_NAME(x29),
+ REG_OFFSET_NAME(x30),
+ REG_OFFSET_NAME(sp),
+ REG_OFFSET_NAME(pc),
+ REG_OFFSET_NAME(pstate),
+ REG_OFFSET_END,
+};
+
/*
* TODO: does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
--
1.8.1.2
Thanks,
-dl
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