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authorLinus Torvalds <torvalds@linux-foundation.org>2019-02-18 09:40:16 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-02-18 09:40:16 -0800
commit10f4902173130fcbb02a69566fefab35fc5f1f30 (patch)
tree51a570111e11bcdbbeb1520ee231dd749690b2ae /kernel
parenta3b22b9f11d9fbc48b0291ea92259a5a810e9438 (diff)
parent9e7382153f80ba45a0bbcd540fb77d4b15f6e966 (diff)
downloadlinux-10f4902173130fcbb02a69566fefab35fc5f1f30.tar.bz2
Merge tag 'trace-v5.0-rc4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt: "Two more tracing fixes - Have kprobes not use copy_from_user() to access kernel addresses, because kprobes can legitimately poke at bad kernel memory, which will fault. Copy from user code should never fault in kernel space. Using probe_mem_read() can handle kernel address space faulting. - Put back the entries counter in the tracing output that was accidentally removed" * tag 'trace-v5.0-rc4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix number of entries in trace header kprobe: Do not use uaccess functions to access kernel memory that can fault
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/trace.c2
-rw-r--r--kernel/trace/trace_kprobe.c10
2 files changed, 3 insertions, 9 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index c521b7347482..c4238b441624 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3384,6 +3384,8 @@ static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file
const char tgid_space[] = " ";
const char space[] = " ";
+ print_event_info(buf, m);
+
seq_printf(m, "# %s _-----=> irqs-off\n",
tgid ? tgid_space : space);
seq_printf(m, "# %s / _----=> need-resched\n",
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index d5fb09ebba8b..9eaf07f99212 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -861,22 +861,14 @@ static const struct file_operations kprobe_profile_ops = {
static nokprobe_inline int
fetch_store_strlen(unsigned long addr)
{
- mm_segment_t old_fs;
int ret, len = 0;
u8 c;
- old_fs = get_fs();
- set_fs(KERNEL_DS);
- pagefault_disable();
-
do {
- ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
+ ret = probe_mem_read(&c, (u8 *)addr + len, 1);
len++;
} while (c && ret == 0 && len < MAX_STRING_SIZE);
- pagefault_enable();
- set_fs(old_fs);
-
return (ret < 0) ? ret : len;
}