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| -rw-r--r-- | man7/feature_test_macros.7 | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/man7/feature_test_macros.7 b/man7/feature_test_macros.7 index eb9bb26c50..6cb73e9b92 100644 --- a/man7/feature_test_macros.7 +++ b/man7/feature_test_macros.7 @@ -479,6 +479,18 @@ With .B _FORTIFY_SOURCE set to 2 some more checking is added, but some conforming programs might fail. +.\" For example, given the following code +.\" int d; +.\" char buf[1000], buf[1000]; +.\" strcpy(fmt, "Hello world\n%n"); +.\" snprintf(buf, sizeof(buf), fmt, &d); +.\" +.\" Compiling with "gcc -D_FORTIFY_SOURCE=2 -O1" and then running will +.\" cause the following diagnostic at runtime at the snprintf() call +.\" +.\" *** %n in writable segment detected *** +.\" Aborted (core dumped) +.\" Some of the checks can be performed at compile time, and result in compiler warnings; other checks take place at run time, |