Call for Testers: mmap autoconf logic

Tue Jan 9 09:55:00 GMT 2001

With cygwin 1.1.7 on a W98 box:
cc: not found
No mmap from /dev/zero.
cc: not found
No mmap with MAP_ANON(YMOUS).
ls: *.l: No such file or directory
When that didn't work, I changed the script to use "gcc" instead of
"cc", and got:
No mmap from /dev/zero.
No mmap with MAP_ANON(YMOUS).
-rw-r--r-- 1 wpd wpd 0 Jan 9 12:53 test1a.l
-rw-r--r-- 1 wpd wpd 0 Jan 9 12:52 test1z.l
Zack Weinberg wrote:
>> I would appreciate it if y'all would run the appended shell script and
> send me its output + any nonempty .l files it generates. (They'll be
> in a subdirectory named "mmt12345" for some value of 12345.)
>> I do not need to know about common, modern systems (*BSD, Linux,
> Solaris, IRIX >=6.2, etc.) nor about systems known to have no mmap(2)
> at all. I am specifically interested in the behavior under cygwin;
> the "works/is buggy" check is supposed to catch several bugs known to
> exist in that mmap implementation.
>> Thanks.
>> zw
>> -- cut here --
> #! /bin/sh
>> mkdir mmt$$ || exit 1
> cd mmt$$ || exit 1
>> cat >testcore.h <<EOF
> /* Test by Richard Henderson and Alexandre Oliva.
> Check whether mmap MAP_ANONYMOUS or mmap from /dev/zero works. */
> #include <sys/types.h>
> #include <sys/param.h>
> #include <sys/mman.h>
> #include <unistd.h>
> #include <stdlib.h>
> #include <fcntl.h>
>> #ifndef MAP_ANON
> # ifdef MAP_ANONYMOUS
> # define MAP_ANON MAP_ANONYMOUS
> # else
> # define MAP_ANON 0
> # endif
> #endif
>> #ifndef MAP_FAILED
> # define MAP_FAILED -1
> #endif
>> static char *
> anonmap (size)
> size_t size;
> {
> #ifdef USE_MAP_ANON
> return (char *) mmap (0, size, PROT_READ|PROT_WRITE,
> MAP_PRIVATE|MAP_ANON, -1, 0);
> #else
> static int devzero = -1;
> if (devzero == -1)
> {
> devzero = open ("/dev/zero", O_RDWR);
> if (devzero < 0)
> exit (1);
> }
> return (char *) mmap (0, size, PROT_READ|PROT_WRITE,
> MAP_PRIVATE, devzero, 0);
> #endif
> }
> EOF
>> cat >test1.c <<EOF
> #include "testcore.h"
>> int
> main()
> {
> int pg = getpagesize ();
> char *x = anonmap (pg);
>> if (x == (char *) MAP_FAILED)
> exit(2);
>> *(int *)x += 1;
>> if (munmap(x, pg) < 0)
> exit(3);
>> exit(0);
> }
> EOF
>> if ${CC-cc} test1.c -o test1z.x >test1z.l 2>&1 && ./test1z.x >>test1z.l 2>&1
> then echo "Have mmap from /dev/zero."
> have_dev_zero=y
> else echo "No mmap from /dev/zero."
> fi
>> if ${CC-cc} test1.c -DUSE_MAP_ANON -o test1a.x >test1a.l 2>&1 \
> && ./test1a.x >>test1a.l 2>&1
> then echo "Have mmap with MAP_ANON(YMOUS)."
> have_map_anon=y
> else echo "No mmap with MAP_ANON(YMOUS)."
> fi
>> cat >test2.c <<EOF
> #include "testcore.h"
> #include <signal.h>
> #include <setjmp.h>
>> /* Some versions of cygwin mmap require that munmap is called with the
> same parameters as mmap. GCC expects that this is not the case.
> Test for various forms of this problem. Warning - icky signal games. */
> static jmp_buf r;
> static size_t pg;
>> static void
> sigsegv (unused)
> int unused;
> {
> longjmp (r, 1);
> }
>> /* 1. If we map a 2-page region and unmap its second page, the first page
> must remain. */
> void
> test_1 ()
> {
> char *x = anonmap (pg * 2);
> if (x == (char *)MAP_FAILED)
> exit (1);
>> signal (SIGSEGV, sigsegv);
> if (setjmp (r))
> exit (2);
>> x[0] = 1;
> x[pg] = 1;
>> munmap (x + pg, pg);
> x[0] = 2;
>> if (setjmp (r))
> {
> munmap (x, pg);
> return;
> }
> x[pg] = 1;
> exit (3);
> }
>> /* 2. If we map a 2-page region and unmap its first page, the second
> page must remain. */
> void
> test_2 ()
> {
> char *x = anonmap (pg * 2);
> if (x == (char *)MAP_FAILED)
> exit (4);
>> signal (SIGSEGV, sigsegv);
> if (setjmp (r))
> exit (5);
>> x[0] = 1;
> x[pg] = 1;
>> munmap (x, pg);
> x[pg] = 2;
>> if (setjmp (r))
> {
> munmap (x + pg, pg);
> return;
> }
> x[0] = 1;
> exit (6);
> }
>> /* 3. If we map two consecutive 1-page regions and unmap them both with
> one munmap, both must go away. */
>> void
> test_3 ()
> {
> char *x = anonmap (pg);
> char *y = anonmap (pg);
> if (x == (char *)MAP_FAILED || y == (char *)MAP_FAILED || x + pg != y)
> exit (7);
>> signal (SIGSEGV, sigsegv);
> if (setjmp (r))
> exit (8);
>> x[0] = 1;
> x[pg] = 1;
>> munmap (x, pg * 2);
>> if (setjmp (r) == 0)
> {
> x[0] = 1;
> exit (9);
> }
>> signal (SIGSEGV, sigsegv);
> if (setjmp (r) == 0)
> {
> x[pg] = 1;
> exit (10);
> }
> }
>> int
> main ()
> {
> pg = getpagesize ();
>> test_1();
> test_2();
> test_3();
>> exit(0);
> }
> EOF
>> if test -n "$have_dev_zero"; then
> if ${CC-cc} test2.c -o test2z.x >test2z.l 2>&1 \
> && ./test2z.x >>test2z.l 2>&1
> then echo "mmap of /dev/zero works."
> else echo "mmap of /dev/zero is buggy. ($?)"
> fi
> fi
>> if test -n "$have_map_anon"; then
> if ${CC-cc} test2.c -DUSE_MAP_ANON -o test2a.x >test2a.l 2>&1 \
> && ./test2a.x >>test2a.l 2>&1
> then echo "mmap with MAP_ANON(YMOUS) works."
> else echo "mmap with MAP_ANON(YMOUS) is buggy. ($?)"
> fi
> fi
>> ls -l *.l
>> --
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