diff options
| -rw-r--r-- | ChangeLog | 8 | ||||
| -rwxr-xr-x | tests/misc/printf-surprise | 55 | ||||
| -rw-r--r-- | tests/test-lib.sh | 15 |
3 files changed, 66 insertions, 12 deletions
@@ -1,5 +1,13 @@ 2007-11-01 Jim Meyering <meyering@redhat.com> + Make the new printf-surprise test more precise. + * tests/test-lib.sh (require_ulimit_): New function. + * tests/misc/printf-surprise: Use ulimit -v to trigger the fixed bug, + and rather than checking printf's exit status (which would go wrong + on FreeBSD 6.1, since their printf(3) function doesn't require + lots of memory in this case) simply test whether it outputs + the first 10 bytes. + Accommodate FreeBSD 6.1 hard-link-to-symlink differences. * tests/cp/same-file: Detect when linking to a symlink links to the target of the symlink (FreeBSD 6.1 does this, Linux does not), diff --git a/tests/misc/printf-surprise b/tests/misc/printf-surprise index 03bc73a41..4e125864a 100755 --- a/tests/misc/printf-surprise +++ b/tests/misc/printf-surprise @@ -24,20 +24,51 @@ if test "$VERBOSE" = yes; then fi . $srcdir/../test-lib.sh +require_ulimit_ fail=0 -# The literal width below is 2^31-1. -# I expect this usage of the printf program to fail. -# However, it depends on the C library printf function. -# It could conceivably output "1." and 2GB worth of '0's. -# You can provoke misbehavior with a much smaller width if you limit -# virtual memory via, e.g., ulimit -v 10000, but using ulimit would -# be tricky, since it's not portable. -"$prog" %.2147483647f 1 > /dev/null 2> err && fail=1 -echo "$prog: cannot perform formatted output: Cannot allocate memory" \ - > exp || framework_failure - -compare err exp || fail=1 +# Up to coreutils-6.9, "printf %.Nf 0" would encounter an ENOMEM internal +# error from glibc's printf(3) function whenever N was large relative to +# the size of available memory. As of Oct 2007, that internal stream- +# related failure was not reflected (for any libc I know of) in the usual +# stream error indicator that is tested by ferror. The result was that +# while the printf command obviously failed (generated no output), +# it mistakenly exited successfully (exit status of 0). + +# Testing it is tricky, because there is so much variance +# in quality for this corner of printf(3) implementations. +# Most implementations do attempt to allocate N bytes of storage. +# Using the maximum value for N (2^31-1) causes glibc to try to +# allocate almost 2^64 bytes, while freeBSD 6.1's implementation +# correctly outputs almost 2GB worth of 0's, which takes too long. +# We want to test implementations that allocate N bytes, but without +# triggering the above extremes. + +# The compromise is to limit virtual memory to something reasonable, +# and to make an N-byte-allocating-printf require more than that, thus +# triggering the printf(3) misbehavior -- which, btw, is required by ISO C99. + +( ulimit -v 10000 + "$prog" %20000000f 0 2>err | head -c 10 >out ) + +# Map this longer, and rarer, diagnostic to the common one. +# printf: cannot perform formatted output: Cannot allocate memory" \ +sed 's/cannot perform/write error/' err > k && mv k err +case $(cat err) in + "$prog: write error") diagnostic=y ;; + '') diagnostic=n ;; + *) diagnostic=unexpected ;; +esac +n_out=$(wc -c < out) + +case $n_out:$diagnostic in + 10:n) ;; # ok, succeeds w/no diagnostic: FreeBSD 6.1 + 0:y) ;; # ok, glibc, when printf(3) fails with ENOMEM + + # 10:y) ;; # Fail: doesn't happen: nobody succeeds with a diagnostic + # 0:n) ;; # Fail pre-patch: no output, no diag + *) fail=1; +esac (exit $fail); exit $fail diff --git a/tests/test-lib.sh b/tests/test-lib.sh index 66fbc1dc4..495fd2a05 100644 --- a/tests/test-lib.sh +++ b/tests/test-lib.sh @@ -14,6 +14,21 @@ skip_test_() (exit 77); exit 77 } +require_ulimit_() +{ + ulimit_works=yes + # Expect to be able to exec a program in 10MB of virtual memory, + # but not in 20KB. I chose "date". It must not be a shell built-in + # function, so you can't use echo, printf, true, etc. + # Of course, in coreutils, I could use $top_builddir/src/true, + # but this should be able to work for other projects, too. + ( ulimit -v 10000; date ) > /dev/null 2>&1 || ulimit_works=no + ( ulimit -v 20; date ) > /dev/null 2>&1 && ulimit_works=no + + test $ulimit_works = no \ + && skip_test_ "this shell lacks ulimit support" +} + uid_is_privileged_() { # Make sure id -u succeeds. |