Fix bug in u_read() #488
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Fix bug in u_read() #488
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Jafaral
requested changes
Oct 27, 2024
src/runtime/rposix.r
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| int newsize = StrLen(*d) + bufsize; | ||
| if ( strfree < (StrLoc(*d) + newsize)) { |
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I suggest a slight optimization by not doing the work unless we actually need to, since in the vast majority of cases we wont be using newsize:
if (strend-strfree < bufsize) {
int newsize = StrLen(*d) + bufsize;
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Of course you can just skip newsize altogether and just do
char *newb = alcstr(NULL, StrLen(*d) + bufsize );
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OK, will do. I suspect that any self respecting compiler will emit almost the same code for either alternative, but it's probably better not to give the compiler the opportunity to not optimise it.
In other places, I've noticed we use
if (Diffptrs(strend,strfree) < bufsize)
so I've gone with that for consistency.
It was possible to overrun the strings region leading to corruption of memory. The new code checks for overrun and allocates a new buffer if it would occur.
Jafaral
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Oct 28, 2024
ValG4
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Dec 7, 2024
Fix bug in u_read()
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It was possible to overrun the strings region leading to corruption of memory. The new code checks for overrun and allocates a new buffer if it would occur.