Skip to content

#3181 printf double vsnprintf() fix, malloc, va_end #3184

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 6 commits into from
Sep 8, 2019
Merged

#3181 printf double vsnprintf() fix, malloc, va_end #3184

Changes from 4 commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
3f5ecc2
Use loc_buf for small strings, check for error return from vsnprintf
knifter Sep 6, 2019
68001da
cleanup arg when bailing out of new
knifter Sep 6, 2019
f1817c0
Use malloc/free instead of new/delete in printf
knifter Sep 6, 2019
e0f0351
Return actual bytes written in printf
knifter Sep 6, 2019
811f27c
FIX: write before free
knifter Sep 6, 2019
c7147a5
Merge branch 'master' into master
me-no-dev Sep 8, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 11 additions & 7 deletions cores/esp32/Print.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -52,21 +52,25 @@ size_t Print::printf(const char *format, ...)
va_list copy;
va_start(arg, format);
va_copy(copy, arg);
size_t len = vsnprintf(NULL, 0, format, copy);
int len = vsnprintf(temp, sizeof(loc_buf), format, copy);
va_end(copy);
if(len < 0) {
va_end(arg);
return 0;
};
if(len >= sizeof(loc_buf)){
temp = new char[len+1];
temp = (char*) malloc(len+1);
if(temp == NULL) {
va_end(arg);
return 0;
}
len = vsnprintf(temp, len+1, format, arg);
}
len = vsnprintf(temp, len+1, format, arg);
write((uint8_t*)temp, len);
va_end(arg);
if(len >= sizeof(loc_buf)){
delete[] temp;
if(temp != loc_buf){
free(temp);
}
return len;
return write((uint8_t*)temp, len);
Copy link
Contributor

@stickbreaker stickbreaker Sep 6, 2019

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

don't do it this way, the buffer has already been freed, free() will overwrite the content of temp with the delete chain links.

Copy link
Contributor Author

@knifter knifter Sep 6, 2019

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

oops... absolutely right, a sec

Copy link
Contributor

@stickbreaker stickbreaker Sep 6, 2019 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

you could:

if(temp != loc_buf){
     len = write((uint8_t*)temp,len);  
     free(temp);
}
else len=write((uint8_t*)temp,len);
return len;

Copy link
Contributor Author

@knifter knifter Sep 6, 2019 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I also want to write(temp) if temp == loc_buf
e: right, too soon. But see commit

}

size_t Print::print(const __FlashStringHelper *ifsh)
Expand Down