diff options
author | Russ Allbery <eagle@eyrie.org> | 2014-07-16 13:46:50 -0700 |
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committer | Russ Allbery <eagle@eyrie.org> | 2014-07-16 13:46:50 -0700 |
commit | 1796d631f0846ec98cd286bc4284898a7300ee78 (patch) | |
tree | 6fd42de6dc858ef06c6d270410c32ec61f39e593 /portable/reallocarray.c | |
parent | f5194217566a6f4cdeffbae551153feb1412210d (diff) | |
parent | 6409733ee3b7b1910dc1c166a392cc628834146c (diff) |
Merge tag 'upstream/1.1' into debian
Upstream version 1.1
Conflicts:
NEWS
README
client/keytab.c
perl/lib/Wallet/ACL.pm
perl/sql/Wallet-Schema-0.08-PostgreSQL.sql
perl/t/general/admin.t
perl/t/verifier/ldap-attr.t
Change-Id: I1a1dc09b97c9258e61f1c8877d0837193c8ae2c6
Diffstat (limited to 'portable/reallocarray.c')
-rw-r--r-- | portable/reallocarray.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/portable/reallocarray.c b/portable/reallocarray.c new file mode 100644 index 0000000..7d40a7a --- /dev/null +++ b/portable/reallocarray.c @@ -0,0 +1,56 @@ +/* + * Replacement for a missing reallocarray. + * + * Provides the same functionality as the OpenBSD library function reallocrray + * for those systems that don't have it. This function is the same as + * realloc, but takes the size arguments in the same form as calloc and checks + * for overflow so that the caller doesn't need to. + * + * The canonical version of this file is maintained in the rra-c-util package, + * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>. + * + * Written by Russ Allbery <eagle@eyrie.org> + * + * The authors hereby relinquish any claim to any copyright that they may have + * in this work, whether granted under contract or by operation of law or + * international treaty, and hereby commit to the public, at large, that they + * shall not, at any time in the future, seek to enforce any copyright in this + * work against any person or entity, or prevent any person or entity from + * copying, publishing, distributing or creating derivative works of this + * work. + */ + +#include <config.h> +#include <portable/system.h> + +#include <errno.h> + +/* + * If we're running the test suite, rename reallocarray to avoid conflicts + * with the system version. #undef it first because some systems may define + * it to another name. + */ +#if TESTING +# undef reallocarray +# define reallocarray test_reallocarray +void *test_reallocarray(void *, size_t, size_t); +#endif + +/* + * nmemb * size cannot overflow if both are smaller than sqrt(SIZE_MAX). We + * can calculate that value statically by using 2^(sizeof(size_t) * 8) as the + * value of SIZE_MAX and then taking the square root, which gives + * 2^(sizeof(size_t) * 4). Compute the exponentiation with shift. + */ +#define CHECK_THRESHOLD (1UL << (sizeof(size_t) * 4)) + +void * +reallocarray(void *ptr, size_t nmemb, size_t size) +{ + if (nmemb >= CHECK_THRESHOLD || size >= CHECK_THRESHOLD) + if (nmemb > 0 && SIZE_MAX / nmemb <= size) { + errno = ENOMEM; + return NULL; + } + return realloc(ptr, nmemb * size); +} |