From 4f7969bcd6d33042d62e249b41b5578161e4c868 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Tue, 31 Oct 2023 15:10:33 -0400 Subject: 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/20231031151033.73c42e23@gandalf.local.home Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mark Rutland Fixes: 0934ae9977c2 ("tracing: Fix reading strings from synthetic events"); Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202311010013.fm8WTxa5-lkp@intel.com/ Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_events_synth.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/trace/trace_events_synth.c') 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); -- cgit