From 5baaa59ef09e8729aef101f7bf7d9d0af00852e3 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Tue, 26 Nov 2013 15:21:04 +0900 Subject: tracing/probes: Implement 'memory' fetch method for uprobes Use separate method to fetch from memory. Move existing functions to trace_kprobe.c and make them static. Also add new memory fetch implementation for uprobes. Acked-by: Masami Hiramatsu Acked-by: Oleg Nesterov Cc: Srikar Dronamraju Cc: zhangwei(Jovi) Cc: Arnaldo Carvalho de Melo Signed-off-by: Namhyung Kim --- kernel/trace/trace_uprobe.c | 52 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) (limited to 'kernel/trace/trace_uprobe.c') diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 24ef6a33d93f..bebd2f5d9ea3 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -114,6 +114,58 @@ DEFINE_BASIC_FETCH_FUNCS(stack) #define fetch_stack_string NULL #define fetch_stack_string_size NULL +#define DEFINE_FETCH_memory(type) \ +static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ + void *addr, void *dest) \ +{ \ + type retval; \ + void __user *vaddr = (void __force __user *) addr; \ + \ + if (copy_from_user(&retval, vaddr, sizeof(type))) \ + *(type *)dest = 0; \ + else \ + *(type *) dest = retval; \ +} +DEFINE_BASIC_FETCH_FUNCS(memory) +/* + * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max + * length and relative data location. + */ +static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, + void *addr, void *dest) +{ + long ret; + u32 rloc = *(u32 *)dest; + int maxlen = get_rloc_len(rloc); + u8 *dst = get_rloc_data(dest); + void __user *src = (void __force __user *) addr; + + if (!maxlen) + return; + + ret = strncpy_from_user(dst, src, maxlen); + + if (ret < 0) { /* Failed to fetch string */ + ((u8 *)get_rloc_data(dest))[0] = '\0'; + *(u32 *)dest = make_data_rloc(0, get_rloc_offs(rloc)); + } else { + *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(rloc)); + } +} + +static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, + void *addr, void *dest) +{ + int len; + void __user *vaddr = (void __force __user *) addr; + + len = strnlen_user(vaddr, MAX_STRING_SIZE); + + if (len == 0 || len > MAX_STRING_SIZE) /* Failed to check length */ + *(u32 *)dest = 0; + else + *(u32 *)dest = len; +} /* uprobes do not support symbol fetch methods */ #define fetch_symbol_u8 NULL -- cgit v1.2.3