On Fri, Jan 25, 2019 at 01:20:09PM -0800, Yonghong Song wrote: > The backtrace-data.c parsed the inode in /proc/pid/maps with > format "%*x". > This caused failure if inode is big. For example, > 7f269223d000-7f269226b000 r-xp 00000000 00:50 10224326387095067468 > /home/...
I have a bit of trouble replicating this (with a simple sscanf). How exactly does it fail? > The correct format should be "%*lu" to reflect inode "unsigned long" type. > But that caused the following compilation error. > acktrace-data.c: In function ‘maps_lookup’: > backtrace-data.c:109:22: error: use of assignment suppression and length > modifier > together in gnu_scanf format [-Werror=format=] > i = fscanf (f, "%lx-%lx %*s %lx %*x:%*x %*lu", &start, &end, &offset); Not that it matters much, since we are really ignoring the rest of the line and this is just a test. But I do wonder why %*u doesn't work. The warning says you cannot combine a length specifier with a ignored format specifier. Which kind of makes sense given that the length is for the variable to assign the value for, not the format. So it seems $*u should do the trick. But since I haven't been able to make the original fail, I might be wrong. Cheers, Mark
