From bfe47f358ad298a1efb9b8f8299a81541d90df87 Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Tue, 17 Dec 2019 14:57:22 +0800 Subject: csky: Implement ptrace regs and stack API Needed for kprobes support. Copied and adapted from Patrick's patch, but it has been modified for csky's pt_regs. ref: https://lore.kernel.org/linux-riscv/1572919114-3886-2-git-send-email-vincent.chen@sifive.com/raw Signed-off-by: Guo Ren Cc: Patrick Staehlin --- arch/csky/Kconfig | 1 + arch/csky/include/asm/ptrace.h | 41 ++++++++++++++++ arch/csky/kernel/ptrace.c | 103 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 145 insertions(+) (limited to 'arch/csky') diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig index 047427f71d83..2dfd3fb07db9 100644 --- a/arch/csky/Kconfig +++ b/arch/csky/Kconfig @@ -48,6 +48,7 @@ config CSKY select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP select HAVE_DMA_CONTIGUOUS + select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS select MAY_HAVE_SPARSE_IRQ diff --git a/arch/csky/include/asm/ptrace.h b/arch/csky/include/asm/ptrace.h index d0aba7b32417..f16ca256e007 100644 --- a/arch/csky/include/asm/ptrace.h +++ b/arch/csky/include/asm/ptrace.h @@ -7,6 +7,7 @@ #include #include #include +#include #ifndef __ASSEMBLY__ @@ -22,6 +23,18 @@ #define instruction_pointer(regs) ((regs)->pc) #define profile_pc(regs) instruction_pointer(regs) +static inline void instruction_pointer_set(struct pt_regs *regs, + unsigned long val) +{ + regs->pc = val; +} + +#if defined(__CSKYABIV2__) +#define MAX_REG_OFFSET offsetof(struct pt_regs, dcsr) +#else +#define MAX_REG_OFFSET offsetof(struct pt_regs, regs[9]) +#endif + static inline bool in_syscall(struct pt_regs const *regs) { return ((regs->sr >> 16) & 0xff) == VEC_TRAP0; @@ -37,5 +50,33 @@ static inline unsigned long regs_return_value(struct pt_regs *regs) return regs->a0; } +/* Valid only for Kernel mode traps. */ +static inline unsigned long kernel_stack_pointer(struct pt_regs *regs) +{ + return regs->usp; +} + +extern int regs_query_register_offset(const char *name); +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 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); +} + #endif /* __ASSEMBLY__ */ #endif /* __ASM_CSKY_PTRACE_H */ diff --git a/arch/csky/kernel/ptrace.c b/arch/csky/kernel/ptrace.c index 313623a19ecb..21ac2608f205 100644 --- a/arch/csky/kernel/ptrace.c +++ b/arch/csky/kernel/ptrace.c @@ -193,6 +193,109 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task) return &user_csky_view; } +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} + +static const struct pt_regs_offset regoffset_table[] = { + REG_OFFSET_NAME(tls), + REG_OFFSET_NAME(lr), + REG_OFFSET_NAME(pc), + REG_OFFSET_NAME(sr), + REG_OFFSET_NAME(usp), + REG_OFFSET_NAME(orig_a0), + REG_OFFSET_NAME(a0), + REG_OFFSET_NAME(a1), + REG_OFFSET_NAME(a2), + REG_OFFSET_NAME(a3), + REG_OFFSET_NAME(regs[0]), + REG_OFFSET_NAME(regs[1]), + REG_OFFSET_NAME(regs[2]), + REG_OFFSET_NAME(regs[3]), + REG_OFFSET_NAME(regs[4]), + REG_OFFSET_NAME(regs[5]), + REG_OFFSET_NAME(regs[6]), + REG_OFFSET_NAME(regs[7]), + REG_OFFSET_NAME(regs[8]), + REG_OFFSET_NAME(regs[9]), +#if defined(__CSKYABIV2__) + REG_OFFSET_NAME(exregs[0]), + REG_OFFSET_NAME(exregs[1]), + REG_OFFSET_NAME(exregs[2]), + REG_OFFSET_NAME(exregs[3]), + REG_OFFSET_NAME(exregs[4]), + REG_OFFSET_NAME(exregs[5]), + REG_OFFSET_NAME(exregs[6]), + REG_OFFSET_NAME(exregs[7]), + REG_OFFSET_NAME(exregs[8]), + REG_OFFSET_NAME(exregs[9]), + REG_OFFSET_NAME(exregs[10]), + REG_OFFSET_NAME(exregs[11]), + REG_OFFSET_NAME(exregs[12]), + REG_OFFSET_NAME(exregs[13]), + REG_OFFSET_NAME(exregs[14]), + REG_OFFSET_NAME(rhi), + REG_OFFSET_NAME(rlo), + REG_OFFSET_NAME(dcsr), +#endif + 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_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. + */ +static 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; +} + void ptrace_disable(struct task_struct *child) { singlestep_disable(child); -- cgit v1.2.3