[PATCH] D54527: Add new interceptor for strtonum(3)

[Vitaly Buka via Phabricator via llvm-commits]

vitalybuka added inline comments.


================
Comment at: test/sanitizer_common/TestCases/NetBSD/strtonum.cc:13
+
+  l = strtonum("100", 1, 100, &errstr);
+  if (errstr)
----------------
krytarowski wrote:
> vitalybuka wrote:
> > vitalybuka wrote:
> > > what is going to happen with following?
> > > strtonum("100 long suffix....", 0, 1000, &errstr)
> > > if this stops parsing just after 100 then COMMON_INTERCEPTOR_READ_RANGE(ctx, nptr, REAL(strlen)(nptr) + 1)  is performance bottleneck
> > > maybe we should get actual read size with StrtolFixAndCheck
> > > 
> > > we had issues with other strto* with strict_string_checks=1 on parsers like python
> > > it just calls such methods in the middle of a large file and you get O(N) -> O(N^2)
> > > 
> > >> maybe we should get actual read size with StrtolFixAndCheck
> > correction: get actual read size with different strto* call and pass it into StrtolFixAndCheck
> `strtonum("100 long suffix....", 0, 1000, &errstr)` it will stop parsin after 100 on ' '.
> 
> src.illumos.org/source/xref/openbsd-src/lib/libc/stdlib/strtonum.c
According implementation form src.illumos.org/source/xref/openbsd-src/lib/libc/stdlib/strtonum.c
it uses strtoll
So if we intercept strtoll, we just need to unpoison errstrp, it it was in existing implementation. What is the problem this patch is solving?


Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D54527/new/

https://reviews.llvm.org/D54527