[PATCH 2/4] ARC: enable HAVE_REGS_AND_STACK_ACCESS_API feature
Sergey Matyukevich
geomatsi at gmail.com
Fri Apr 8 08:58:02 PDT 2022
From: Sergey Matyukevich <sergey.matyukevich at synopsys.com>
Enable HAVE_REGS_AND_STACK_ACCESS_API feature for ARC architecture,
including ARCcompact and ARCv2 flavors. Add supporting functions
and defines.
Signed-off-by: Sergey Matyukevich <sergey.matyukevich at synopsys.com>
---
arch/arc/Kconfig | 1 +
arch/arc/include/asm/ptrace.h | 27 ++++++++
arch/arc/kernel/ptrace.c | 119 ++++++++++++++++++++++++++++++++++
3 files changed, 147 insertions(+)
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index e0a60a27e14d..3c850d0f431c 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -36,6 +36,7 @@ config ARC
select HAVE_KERNEL_LZMA
select HAVE_KPROBES
select HAVE_KRETPROBES
+ select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_MOD_ARCH_SPECIFIC
select HAVE_PERF_EVENTS
select IRQ_DOMAIN
diff --git a/arch/arc/include/asm/ptrace.h b/arch/arc/include/asm/ptrace.h
index cca8d6583e31..5869a74c0db2 100644
--- a/arch/arc/include/asm/ptrace.h
+++ b/arch/arc/include/asm/ptrace.h
@@ -8,6 +8,7 @@
#define __ASM_ARC_PTRACE_H
#include <uapi/asm/ptrace.h>
+#include <linux/compiler.h>
#ifndef __ASSEMBLY__
@@ -54,6 +55,9 @@ struct pt_regs {
unsigned long user_r25;
};
+
+#define MAX_REG_OFFSET offsetof(struct pt_regs, user_r25)
+
#else
struct pt_regs {
@@ -102,6 +106,8 @@ struct pt_regs {
unsigned long status32;
};
+#define MAX_REG_OFFSET offsetof(struct pt_regs, status32)
+
#endif
/* Callee saved registers - need to be saved only when you are scheduled out */
@@ -154,6 +160,27 @@ static inline void instruction_pointer_set(struct pt_regs *regs,
{
instruction_pointer(regs) = val;
}
+
+static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
+{
+ return regs->sp;
+}
+
+extern int regs_query_register_offset(const char *name);
+extern const char *regs_query_register_name(unsigned int offset);
+extern bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr);
+extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
+ unsigned int n);
+
+static inline unsigned long regs_get_register(struct pt_regs *regs,
+ unsigned int offset)
+{
+ if (unlikely(offset > MAX_REG_OFFSET))
+ return 0;
+
+ return *(unsigned long *)((unsigned long)regs + offset);
+}
+
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_PTRACE_H */
diff --git a/arch/arc/kernel/ptrace.c b/arch/arc/kernel/ptrace.c
index 54b419ac8bda..5fa5bceb83f3 100644
--- a/arch/arc/kernel/ptrace.c
+++ b/arch/arc/kernel/ptrace.c
@@ -9,6 +9,89 @@
#include <linux/unistd.h>
#include <linux/elf.h>
+struct pt_regs_offset {
+ const char *name;
+ int offset;
+};
+
+#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
+#define REG_OFFSET_END {.name = NULL, .offset = 0}
+
+#ifdef CONFIG_ISA_ARCOMPACT
+static const struct pt_regs_offset regoffset_table[] = {
+ REG_OFFSET_NAME(bta),
+ REG_OFFSET_NAME(lp_start),
+ REG_OFFSET_NAME(lp_end),
+ REG_OFFSET_NAME(lp_count),
+ REG_OFFSET_NAME(status32),
+ REG_OFFSET_NAME(ret),
+ REG_OFFSET_NAME(blink),
+ REG_OFFSET_NAME(fp),
+ REG_OFFSET_NAME(r26),
+ REG_OFFSET_NAME(r12),
+ REG_OFFSET_NAME(r11),
+ REG_OFFSET_NAME(r10),
+ REG_OFFSET_NAME(r9),
+ REG_OFFSET_NAME(r8),
+ REG_OFFSET_NAME(r7),
+ REG_OFFSET_NAME(r6),
+ REG_OFFSET_NAME(r5),
+ REG_OFFSET_NAME(r4),
+ REG_OFFSET_NAME(r3),
+ REG_OFFSET_NAME(r2),
+ REG_OFFSET_NAME(r1),
+ REG_OFFSET_NAME(r0),
+ REG_OFFSET_NAME(sp),
+ REG_OFFSET_NAME(orig_r0),
+ REG_OFFSET_NAME(event),
+ REG_OFFSET_NAME(user_r25),
+ REG_OFFSET_END,
+};
+
+#else
+
+static const struct pt_regs_offset regoffset_table[] = {
+ REG_OFFSET_NAME(orig_r0),
+ REG_OFFSET_NAME(event),
+ REG_OFFSET_NAME(bta),
+ REG_OFFSET_NAME(user_r25),
+ REG_OFFSET_NAME(r26),
+ REG_OFFSET_NAME(fp),
+ REG_OFFSET_NAME(sp),
+ REG_OFFSET_NAME(r12),
+ REG_OFFSET_NAME(r30),
+#ifdef CONFIG_ARC_HAS_ACCL_REGS
+ REG_OFFSET_NAME(r58),
+ REG_OFFSET_NAME(r59),
+#endif
+#ifdef CONFIG_ARC_DSP_SAVE_RESTORE_REGS
+ REG_OFFSET_NAME(DSP_CTRL),
+#endif
+ REG_OFFSET_NAME(r0),
+ REG_OFFSET_NAME(r1),
+ REG_OFFSET_NAME(r2),
+ REG_OFFSET_NAME(r3),
+ REG_OFFSET_NAME(r4),
+ REG_OFFSET_NAME(r5),
+ REG_OFFSET_NAME(r6),
+ REG_OFFSET_NAME(r7),
+ REG_OFFSET_NAME(r8),
+ REG_OFFSET_NAME(r9),
+ REG_OFFSET_NAME(r10),
+ REG_OFFSET_NAME(r11),
+ REG_OFFSET_NAME(blink),
+ REG_OFFSET_NAME(lp_end),
+ REG_OFFSET_NAME(lp_start),
+ REG_OFFSET_NAME(lp_count),
+ REG_OFFSET_NAME(ei),
+ REG_OFFSET_NAME(ldi),
+ REG_OFFSET_NAME(jli),
+ REG_OFFSET_NAME(ret),
+ REG_OFFSET_NAME(status32),
+ REG_OFFSET_END,
+};
+#endif
+
static struct callee_regs *task_callee_regs(struct task_struct *tsk)
{
struct callee_regs *tmp = (struct callee_regs *)tsk->thread.callee_reg;
@@ -267,3 +350,39 @@ asmlinkage void syscall_trace_exit(struct pt_regs *regs)
{
ptrace_report_syscall_exit(regs, 0);
}
+
+int regs_query_register_offset(const char *name)
+{
+ const struct pt_regs_offset *roff;
+
+ for (roff = regoffset_table; roff->name != NULL; roff++)
+ if (!strcmp(roff->name, name))
+ return roff->offset;
+ return -EINVAL;
+}
+
+const char *regs_query_register_name(unsigned int offset)
+{
+ const struct pt_regs_offset *roff;
+ for (roff = regoffset_table; roff->name != NULL; roff++)
+ if (roff->offset == offset)
+ return roff->name;
+ return NULL;
+}
+
+bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
+{
+ return (addr & ~(THREAD_SIZE - 1)) ==
+ (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
+}
+
+unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
+{
+ unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
+
+ addr += n;
+ if (regs_within_kernel_stack(regs, (unsigned long)addr))
+ return *addr;
+ else
+ return 0;
+}
--
2.35.1
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