getcwd() has two off-by-one bugs in FreeBSD-2.0:
1. getcwd(buf, size) fails when the size is just large enough.
2. getcwd(buf + 1, 1) incorrectly succeeds when the current directory
is "/". buf[0] and buf[2] are clobbered.
(I modified Bruce's original patch to return the proper error code
[ERANGE] in the case of #2, but otherwise... -DG)
This program demonstrates the bug:
---
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
int main(void)
{
char buf[5];
int errors;
errors = 0;
if (chdir("/tmp") != 0) {
perror("chdir");
abort();
}
if (getcwd(buf, 5) == NULL) {
perror("oops, getcwd failed for buffer size = size required");
++errors;
}
if (chdir("/") != 0) {
perror("chdir");
abort();
}
buf[0] = 0;
buf[2] = 1;
if (getcwd(buf + 1, 1) != NULL) {
fprintf(stderr,
"oops, getcwd succeeded for buffer size = one too small\n");
++errors;
}
if (buf[0] != 0) {
fprintf(stderr,
"oops, getcwd scribbled on memory before start of buffer\n");
++errors;
}
if (buf[2] != 1) {
fprintf(stderr,
"oops, getcwd scribbled on memory after end of buffer\n");
++errors;
}
exit(errors == 0 ? 0 : 1);
}
pointer returned by realloc(). All callers free the pointer if the
execve fails. Nuke the caching. This essentially restores buildargv()
to the 1.1.5 version. Also fix a memory leak if realloc() fails. Also
nuke similar but non-broken caching in execvp(). malloc() should be
efficient enough.
Prepare for disk slices - more macros for handling disk device numbers,
version of readdisklabel() without DOS goop.
Clean up prototypes.
Uniformize idempotency ifdef.
diskslice.h:
New file.
dkbad.h:
Define more magic numbers.
Declare internalized version of dkbad struct and functions to operate on it.
Uniformize idempotency ifdef.
command available yet.
Changed an entry in getprcent.3 from rpcinfo(8C) to rpcinfo(8).
Changed an entry in getrpcport.3 from 3R to 3.
Changed two entries in rpc.3 from 3N to 3.
worked in the past only because of good fortune. Anyway, use the contig alloc
routine I wrote awhile ago (vm_page_alloc_contig) for the sound code to do
this allocation. Also, specify read+write on the permissions to pmap_enter().
Specifying just read can have unexpected consquences.
