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authorSteven Rostedt (Google) <[email protected]>2023-10-31 15:10:33 -0400
committerSteven Rostedt (Google) <[email protected]>2023-11-01 23:46:05 -0400
commit4f7969bcd6d33042d62e249b41b5578161e4c868 (patch)
tree4a016504c1d0c2e2c2421ed30346769329483566
parent77bc4d4921bd3497678ba8e7f4e480de35692f05 (diff)
tracing: Have the user copy of synthetic event address use correct context
A synthetic event is created by the synthetic event interface that can read both user or kernel address memory. In reality, it reads any arbitrary memory location from within the kernel. If the address space is in USER (where CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE is set) then it uses strncpy_from_user_nofault() to copy strings otherwise it uses strncpy_from_kernel_nofault(). But since both functions use the same variable there's no annotation to what that variable is (ie. __user). This makes sparse complain. Quiet sparse by typecasting the strncpy_from_user_nofault() variable to a __user pointer. Link: https://lore.kernel.org/linux-trace-kernel/[email protected] Cc: [email protected] Cc: Masami Hiramatsu <[email protected]> Cc: Mark Rutland <[email protected]> Fixes: 0934ae9977c2 ("tracing: Fix reading strings from synthetic events"); Reported-by: kernel test robot <[email protected]> Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/ Signed-off-by: Steven Rostedt (Google) <[email protected]>
-rw-r--r--kernel/trace/trace_events_synth.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index 14cb275a0bab..846e02c0fb59 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -452,7 +452,7 @@ static unsigned int trace_string(struct synth_trace_event *entry,
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
if ((unsigned long)str_val < TASK_SIZE)
- ret = strncpy_from_user_nofault(str_field, str_val, STR_VAR_LEN_MAX);
+ ret = strncpy_from_user_nofault(str_field, (const void __user *)str_val, STR_VAR_LEN_MAX);
else
#endif
ret = strncpy_from_kernel_nofault(str_field, str_val, STR_VAR_LEN_MAX);