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author | Jakub Jelinek <jakub@redhat.com> | 2023-10-12 16:07:25 +0200 |
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committer | Jakub Jelinek <jakub@redhat.com> | 2023-10-12 16:07:25 +0200 |
commit | fb590e4eeb1aa897209b853430dc4854ece97802 (patch) | |
tree | dfed0714e41cd12bdf545d85d1cef598be58d5c5 /gcc | |
parent | 0d00385eaf72ccacff17935b0d214a26773e095f (diff) | |
download | gcc-fb590e4eeb1aa897209b853430dc4854ece97802.zip gcc-fb590e4eeb1aa897209b853430dc4854ece97802.tar.gz gcc-fb590e4eeb1aa897209b853430dc4854ece97802.tar.bz2 |
wide-int: Add simple CHECKING_P stack-protector canary like checking
This patch adds hopefully not so expensive --enable-checking=yes
verification that the widest_int upper length bound estimates are really
upper bounds and nothing attempts to write more elements.
It is done only if the estimated upper length bound is smaller than
WIDE_INT_MAX_INL_ELTS, but that should be the most common case unless
large _BitInt is involved.
2023-10-12 Jakub Jelinek <jakub@redhat.com>
* wide-int.h (widest_int_storage <N>::write_val): If l is small
and there is space in u.val array, store a canary value at the
end when checking.
(widest_int_storage <N>::set_len): Check the canary hasn't been
overwritten.
Diffstat (limited to 'gcc')
-rw-r--r-- | gcc/wide-int.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/gcc/wide-int.h b/gcc/wide-int.h index 1b12472..07bacc9 100644 --- a/gcc/wide-int.h +++ b/gcc/wide-int.h @@ -1635,6 +1635,8 @@ widest_int_storage <N>::write_val (unsigned int l) u.valp = XNEWVEC (HOST_WIDE_INT, l); return u.valp; } + else if (CHECKING_P && l < WIDE_INT_MAX_INL_ELTS) + u.val[l] = HOST_WIDE_INT_UC (0xbaaaaaaddeadbeef); return u.val; } @@ -1650,6 +1652,9 @@ widest_int_storage <N>::set_len (unsigned int l, bool) memcpy (u.val, valp, l * sizeof (u.val[0])); XDELETEVEC (valp); } + else if (len && len < WIDE_INT_MAX_INL_ELTS) + gcc_checking_assert ((unsigned HOST_WIDE_INT) u.val[len] + == HOST_WIDE_INT_UC (0xbaaaaaaddeadbeef)); len = l; /* There are no excess bits in val[len - 1]. */ STATIC_ASSERT (N % HOST_BITS_PER_WIDE_INT == 0); |