diff options
| -rw-r--r-- | arch/arm/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm/include/asm/ptrace.h | 36 | ||||
| -rw-r--r-- | arch/arm/kernel/ptrace.c | 96 |
3 files changed, 133 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 9a0ed364d4f7..aa738aa70c78 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -24,6 +24,7 @@ config ARM select HAVE_KERNEL_LZMA select HAVE_PERF_EVENTS select PERF_USE_VMALLOC + select HAVE_REGS_AND_STACK_ACCESS_API help The ARM series is a line of low-power-consumption RISC chip designs licensed by ARM Ltd and targeted at embedded applications and diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h index 9dcb11e59026..c974be8913a7 100644 --- a/arch/arm/include/asm/ptrace.h +++ b/arch/arm/include/asm/ptrace.h @@ -184,6 +184,42 @@ extern unsigned long profile_pc(struct pt_regs *regs); #define predicate(x) ((x) & 0xf0000000) #define PREDICATE_ALWAYS 0xe0000000 +/* + * kprobe-based event tracer support + */ +#include <linux/stddef.h> +#include <linux/types.h> +#define MAX_REG_OFFSET (offsetof(struct pt_regs, ARM_ORIG_r0)) + +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); + +/** + * 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 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); +} + +/* Valid only for Kernel mode traps. */ +static inline unsigned long kernel_stack_pointer(struct pt_regs *regs) +{ + return regs->ARM_sp; +} + #endif /* __KERNEL__ */ #endif /* __ASSEMBLY__ */ diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c index 3f562a7c0a99..f99d489822d5 100644 --- a/arch/arm/kernel/ptrace.c +++ b/arch/arm/kernel/ptrace.c @@ -52,6 +52,102 @@ #define BREAKINST_THUMB 0xde01 #endif +struct pt_regs_offset { + const char *name; + int offset; +}; + +#define REG_OFFSET_NAME(r) \ + {.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)} +#define REG_OFFSET_END {.name = NULL, .offset = 0} + +static const struct pt_regs_offset regoffset_table[] = { + 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(fp), + REG_OFFSET_NAME(ip), + REG_OFFSET_NAME(sp), + REG_OFFSET_NAME(lr), + REG_OFFSET_NAME(pc), + REG_OFFSET_NAME(cpsr), + REG_OFFSET_NAME(ORIG_r0), + REG_OFFSET_END, +}; + +/** + * regs_query_register_offset() - query register offset from its name + * @name: the name of a register + * + * regs_query_register_offset() returns the offset of a register in struct + * pt_regs from its name. If the name is invalid, this returns -EINVAL; + */ +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; +} + +/** + * regs_query_register_name() - query register name from its offset + * @offset: the offset of a register in struct pt_regs. + * + * regs_query_register_name() returns the name of a register from its + * offset in struct pt_regs. If the @offset is invalid, this returns NULL; + */ +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; +} + +/** + * regs_within_kernel_stack() - check the address in the stack + * @regs: pt_regs which contains kernel stack pointer. + * @addr: address which is checked. + * + * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). + * If @addr is within the kernel stack, it returns true. If not, returns false. + */ +bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr) +{ + return ((addr & ~(THREAD_SIZE - 1)) == + (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); +} + +/** + * regs_get_kernel_stack_nth() - get Nth entry of the stack + * @regs: pt_regs which contains kernel stack pointer. + * @n: stack entry number. + * + * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which + * is specified by @regs. If the @n th entry is NOT in the kernel stack, + * this returns 0. + */ +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; +} + /* * this routine will get a word off of the processes privileged stack. * the offset is how far from the base addr as stored in the THREAD. |