From ea1afe339a2b1260aa31a4d100155d4403446704 Mon Sep 17 00:00:00 2001 From: Sven Schnelle Date: Sun, 7 Apr 2019 20:10:57 +0200 Subject: [PATCH] parisc: add functions required by KPROBE_EVENTS implement regs_get_register(), regs_get_kernel_stack_nth() and regs_within_kernel_stack() Signed-off-by: Sven Schnelle Signed-off-by: Helge Deller --- arch/parisc/include/asm/ptrace.h | 13 ++++++++++++ arch/parisc/kernel/ptrace.c | 35 ++++++++++++++++++++++++++++++++ 2 files changed, 48 insertions(+) diff --git a/arch/parisc/include/asm/ptrace.h b/arch/parisc/include/asm/ptrace.h index 9ff033d261ab..143fb2a89dd8 100644 --- a/arch/parisc/include/asm/ptrace.h +++ b/arch/parisc/include/asm/ptrace.h @@ -37,4 +37,17 @@ extern int regs_query_register_offset(const char *name); extern const char *regs_query_register_name(unsigned int offset); #define MAX_REG_OFFSET (offsetof(struct pt_regs, ipsw)) +#define kernel_stack_pointer(regs) ((regs)->gr[30]) + +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); +} + +unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n); +int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr); + #endif diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c index 0964c236e3e5..a3d2fb4e6dd2 100644 --- a/arch/parisc/kernel/ptrace.c +++ b/arch/parisc/kernel/ptrace.c @@ -789,3 +789,38 @@ const char *regs_query_register_name(unsigned int 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. + */ +int 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 0; + + return *addr; +} -- 2.45.2