When matching by PID, we'd better return ESRCH expicitly rather
than zero entries. This makes, for example, fstat(1) behaviour
more consistent and makes it easier to replace "if lsof -p ..."
checks in third-party code with "if fstat -p ...".
For libkvm, I explicitly test for ESRCH to avoid going inside
kmem without real need.
Tested on amd64.
Comments? Okays?
--
WBR,
Vadim Zhukov
Index: sys/kern/kern_sysctl.c
===================================================================
RCS file: /cvs/src/sys/kern/kern_sysctl.c,v
retrieving revision 1.300
diff -u -p -r1.300 kern_sysctl.c
--- sys/kern/kern_sysctl.c 29 Feb 2016 19:44:07 -0000 1.300
+++ sys/kern/kern_sysctl.c 30 Apr 2016 22:26:06 -0000
@@ -1225,7 +1225,7 @@ sysctl_file(int *name, u_int namelen, ch
struct process *pr;
size_t buflen, elem_size, elem_count, outsize;
char *dp = where;
- int arg, i, error = 0, needed = 0;
+ int arg, i, error = 0, needed = 0, matched;
u_int op;
int show_pointers;
@@ -1325,6 +1325,7 @@ sysctl_file(int *name, u_int namelen, ch
error = EINVAL;
break;
}
+ matched = (arg <= 0);
LIST_FOREACH(pr, &allprocess, ps_list) {
/*
* skip system, exiting, embryonic and undead
@@ -1332,9 +1333,12 @@ sysctl_file(int *name, u_int namelen, ch
*/
if (pr->ps_flags & (PS_SYSTEM | PS_EMBRYO | PS_EXITING))
continue;
- if (arg > 0 && pr->ps_pid != (pid_t)arg) {
- /* not the pid we are looking for */
- continue;
+ if (arg > 0) {
+ /* is this the pid we are looking for? */
+ if (pr->ps_pid == (pid_t)arg)
+ matched = 1;
+ else
+ continue;
}
fdp = pr->ps_fd;
if (pr->ps_textvp)
@@ -1353,6 +1357,8 @@ sysctl_file(int *name, u_int namelen, ch
FILLIT(fp, fdp, i, NULL, pr);
}
}
+ if (!matched)
+ error = ESRCH;
break;
case KERN_FILE_BYUID:
LIST_FOREACH(pr, &allprocess, ps_list) {
Index: lib/libkvm/kvm_file2.c
===================================================================
RCS file: /cvs/src/lib/libkvm/kvm_file2.c,v
retrieving revision 1.47
diff -u -p -r1.47 kvm_file2.c
--- lib/libkvm/kvm_file2.c 4 Sep 2015 02:58:14 -0000 1.47
+++ lib/libkvm/kvm_file2.c 30 Apr 2016 22:26:06 -0000
@@ -149,7 +149,7 @@ kvm_getfiles(kvm_t *kd, int op, int arg,
/* find size and alloc buffer */
rv = sysctl(mib, 6, NULL, &size, NULL, 0);
if (rv == -1) {
- if (kd->vmfd != -1)
+ if (errno != ESRCH && kd->vmfd != -1)
goto deadway;
_kvm_syserr(kd, kd->program, "kvm_getfiles");
return (NULL);
@@ -266,7 +266,7 @@ kvm_deadfile_byid(kvm_t *kd, int op, int
{
size_t buflen;
struct nlist nl[4], *np;
- int n = 0;
+ int n = 0, matched = 0;
char *where;
struct kinfo_file kf;
struct file *fp, file;
@@ -312,6 +312,9 @@ kvm_deadfile_byid(kvm_t *kd, int op, int
kd->filebase = (void *)where;
buflen = (nfiles + 10) * esize;
+ if (op != KERN_FILE_BYPID || arg <= 0)
+ matched = 1;
+
for (pr = LIST_FIRST(&allprocess);
pr != NULL;
pr = LIST_NEXT(&process, ps_list)) {
@@ -333,10 +336,12 @@ kvm_deadfile_byid(kvm_t *kd, int op, int
goto cleanup;
}
- if (op == KERN_FILE_BYPID && arg > 0 &&
- proc.p_pid != (pid_t)arg) {
- /* not the pid we are looking for */
+ if (op == KERN_FILE_BYPID) {
+ /* check if this is the pid we are looking for */
+ if (arg > 0 && proc.p_pid != (pid_t)arg)
continue;
+ else
+ matched = 1;
}
if (KREAD(kd, (u_long)process.ps_ucred, &ucred)) {
@@ -457,6 +462,10 @@ kvm_deadfile_byid(kvm_t *kd, int op, int
buflen -= esize;
n++;
}
+ }
+ if (!matched) {
+ errno = ESRCH;
+ goto cleanup;
}
done:
*cnt = n;
