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| author | Alexei Starovoitov <ast@plumgrid.com> | 2015-08-29 00:56:22 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-08-29 01:27:27 +0200 |
| commit | 1a6877b9c0c2ad901d4335d909432d3bb6d3a330 (patch) | |
| tree | 25b3a1577a82199d1100834c1bbf6cefad34a5a7 /kernel/trace/trace_kprobe.c | |
| parent | netpoll: warn on netpoll_send_udp users who haven't disabled irqs (diff) | |
| download | linux-1a6877b9c0c2ad901d4335d909432d3bb6d3a330.tar.xz linux-1a6877b9c0c2ad901d4335d909432d3bb6d3a330.zip | |
lib: introduce strncpy_from_unsafe()
generalize FETCH_FUNC_NAME(memory, string) into
strncpy_from_unsafe() and fix sparse warnings that were
present in original implementation.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel/trace/trace_kprobe.c')
| -rw-r--r-- | kernel/trace/trace_kprobe.c | 20 |
1 files changed, 4 insertions, 16 deletions
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index b7d0cdd9906c..c9956440d0e6 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -165,11 +165,9 @@ DEFINE_BASIC_FETCH_FUNCS(memory) static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, void *addr, void *dest) { - long ret; int maxlen = get_rloc_len(*(u32 *)dest); u8 *dst = get_rloc_data(dest); - u8 *src = addr; - mm_segment_t old_fs = get_fs(); + long ret; if (!maxlen) return; @@ -178,23 +176,13 @@ static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, * Try to get string again, since the string can be changed while * probing. */ - set_fs(KERNEL_DS); - pagefault_disable(); - - do - ret = __copy_from_user_inatomic(dst++, src++, 1); - while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen); - - dst[-1] = '\0'; - pagefault_enable(); - set_fs(old_fs); + ret = strncpy_from_unsafe(dst, addr, maxlen); if (ret < 0) { /* Failed to fetch string */ - ((u8 *)get_rloc_data(dest))[0] = '\0'; + dst[0] = '\0'; *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); } else { - *(u32 *)dest = make_data_rloc(src - (u8 *)addr, - get_rloc_offs(*(u32 *)dest)); + *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest)); } } NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string)); |