tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: aae703b02f92bde9264366c545e87cec451de471
commit: 0934ae9977c27133449b6dd8c6213970e7eece38 tracing: Fix reading strings from synthetic events
date: 6 days ago
config: x86_64-randconfig-s022-20221017
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce:
# apt-get install sparse
# sparse version: v0.6.4-39-gce1a6720-dirty
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0934ae9977c27133449b6dd8c6213970e7eece38
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 0934ae9977c27133449b6dd8c6213970e7eece38
# save the config file
mkdir build_dir && cp config build_dir/.config
make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=x86_64 SHELL=/bin/bash kernel/trace/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <[email protected]>
sparse warnings: (new ones prefixed by >>)
>> kernel/trace/trace_events_synth.c:436:68: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected void const [noderef] __user *unsafe_addr @@ got char *str_val @@
kernel/trace/trace_events_synth.c:436:68: sparse: expected void const [noderef] __user *unsafe_addr
kernel/trace/trace_events_synth.c:436:68: sparse: got char *str_val
vim +436 kernel/trace/trace_events_synth.c
404
405 static unsigned int trace_string(struct synth_trace_event *entry,
406 struct synth_event *event,
407 char *str_val,
408 bool is_dynamic,
409 unsigned int data_size,
410 unsigned int *n_u64)
411 {
412 unsigned int len = 0;
413 char *str_field;
414 int ret;
415
416 if (is_dynamic) {
417 u32 data_offset;
418
419 data_offset = offsetof(typeof(*entry), fields);
420 data_offset += event->n_u64 * sizeof(u64);
421 data_offset += data_size;
422
423 len = kern_fetch_store_strlen((unsigned long)str_val);
424
425 data_offset |= len << 16;
426 *(u32 *)&entry->fields[*n_u64] = data_offset;
427
428 ret = kern_fetch_store_string((unsigned long)str_val, &entry->fields[*n_u64], entry);
429
430 (*n_u64)++;
431 } else {
432 str_field = (char *)&entry->fields[*n_u64];
433
434 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
435 if ((unsigned long)str_val < TASK_SIZE)
> 436 ret = strncpy_from_user_nofault(str_field, str_val, STR_VAR_LEN_MAX);
437 else
438 #endif
439 ret = strncpy_from_kernel_nofault(str_field, str_val, STR_VAR_LEN_MAX);
440
441 if (ret < 0)
442 strcpy(str_field, FAULT_STRING);
443
444 (*n_u64) += STR_VAR_LEN_MAX / sizeof(u64);
445 }
446
447 return len;
448 }
449
--
0-DAY CI Kernel Test Service
https://01.org/lkp
On Wed, 19 Oct 2022 11:43:54 +0800
kernel test robot <[email protected]> wrote:
> sparse warnings: (new ones prefixed by >>)
> >> kernel/trace/trace_events_synth.c:436:68: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected void const [noderef] __user *unsafe_addr @@ got char *str_val @@
> kernel/trace/trace_events_synth.c:436:68: sparse: expected void const [noderef] __user *unsafe_addr
> kernel/trace/trace_events_synth.c:436:68: sparse: got char *str_val
>
> vim +436 kernel/trace/trace_events_synth.c
>
> 404
> 405 static unsigned int trace_string(struct synth_trace_event *entry,
> 406 struct synth_event *event,
> 407 char *str_val,
> 408 bool is_dynamic,
> 409 unsigned int data_size,
> 410 unsigned int *n_u64)
> 411 {
> 412 unsigned int len = 0;
> 413 char *str_field;
> 414 int ret;
> 415
> 416 if (is_dynamic) {
> 417 u32 data_offset;
> 418
> 419 data_offset = offsetof(typeof(*entry), fields);
> 420 data_offset += event->n_u64 * sizeof(u64);
> 421 data_offset += data_size;
> 422
> 423 len = kern_fetch_store_strlen((unsigned long)str_val);
> 424
> 425 data_offset |= len << 16;
> 426 *(u32 *)&entry->fields[*n_u64] = data_offset;
> 427
> 428 ret = kern_fetch_store_string((unsigned long)str_val, &entry->fields[*n_u64], entry);
> 429
> 430 (*n_u64)++;
> 431 } else {
> 432 str_field = (char *)&entry->fields[*n_u64];
> 433
> 434 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
> 435 if ((unsigned long)str_val < TASK_SIZE)
> > 436 ret = strncpy_from_user_nofault(str_field, str_val, STR_VAR_LEN_MAX);
> 437 else
> 438 #endif
> 439 ret = strncpy_from_kernel_nofault(str_field, str_val, STR_VAR_LEN_MAX);
> 440
Does this fix it?
-- Steve
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index e310052dc83c..2562d7522999 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -433,7 +433,8 @@ 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,
+ (__force const void __user *)str_val, STR_VAR_LEN_MAX);
else
#endif
ret = strncpy_from_kernel_nofault(str_field, str_val, STR_VAR_LEN_MAX);
On 10/19/2022 9:34 PM, Steven Rostedt wrote:
> On Wed, 19 Oct 2022 11:43:54 +0800
> kernel test robot <[email protected]> wrote:
>
>> sparse warnings: (new ones prefixed by >>)
>>>> kernel/trace/trace_events_synth.c:436:68: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected void const [noderef] __user *unsafe_addr @@ got char *str_val @@
>> kernel/trace/trace_events_synth.c:436:68: sparse: expected void const [noderef] __user *unsafe_addr
>> kernel/trace/trace_events_synth.c:436:68: sparse: got char *str_val
>>
>> vim +436 kernel/trace/trace_events_synth.c
>>
>> 404
>> 405 static unsigned int trace_string(struct synth_trace_event *entry,
>> 406 struct synth_event *event,
>> 407 char *str_val,
>> 408 bool is_dynamic,
>> 409 unsigned int data_size,
>> 410 unsigned int *n_u64)
>> 411 {
>> 412 unsigned int len = 0;
>> 413 char *str_field;
>> 414 int ret;
>> 415
>> 416 if (is_dynamic) {
>> 417 u32 data_offset;
>> 418
>> 419 data_offset = offsetof(typeof(*entry), fields);
>> 420 data_offset += event->n_u64 * sizeof(u64);
>> 421 data_offset += data_size;
>> 422
>> 423 len = kern_fetch_store_strlen((unsigned long)str_val);
>> 424
>> 425 data_offset |= len << 16;
>> 426 *(u32 *)&entry->fields[*n_u64] = data_offset;
>> 427
>> 428 ret = kern_fetch_store_string((unsigned long)str_val, &entry->fields[*n_u64], entry);
>> 429
>> 430 (*n_u64)++;
>> 431 } else {
>> 432 str_field = (char *)&entry->fields[*n_u64];
>> 433
>> 434 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
>> 435 if ((unsigned long)str_val < TASK_SIZE)
>> > 436 ret = strncpy_from_user_nofault(str_field, str_val, STR_VAR_LEN_MAX);
>> 437 else
>> 438 #endif
>> 439 ret = strncpy_from_kernel_nofault(str_field, str_val, STR_VAR_LEN_MAX);
>> 440
>
>
> Does this fix it?
Hi Steve,
I tried the below patch, it can fix the issue.
Best Regards,
Rong Chen
>
> -- Steve
>
> diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
> index e310052dc83c..2562d7522999 100644
> --- a/kernel/trace/trace_events_synth.c
> +++ b/kernel/trace/trace_events_synth.c
> @@ -433,7 +433,8 @@ 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,
> + (__force const void __user *)str_val, STR_VAR_LEN_MAX);
> else
> #endif
> ret = strncpy_from_kernel_nofault(str_field, str_val, STR_VAR_LEN_MAX);
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