The branch main has been updated by dougm: URL: https://cgit.FreeBSD.org/src/commit/?id=e5f93d10782dd804d0ee776c22b972ec582f5c99
commit e5f93d10782dd804d0ee776c22b972ec582f5c99 Author: Doug Moore <[email protected]> AuthorDate: 2022-10-01 17:20:04 +0000 Commit: Doug Moore <[email protected]> CommitDate: 2022-10-01 17:20:04 +0000 show_sysctl_all: reduce copying, please coverity Modify db_show_sysctl_all so that it does not copy more than once the data of the input oid, and so that what it passes to db_show_oid does not alarm coverity. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D36847 --- sys/kern/kern_sysctl.c | 47 ++++++++++++++++++++++------------------------- 1 file changed, 22 insertions(+), 25 deletions(-) diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c index 8e4b69bb6eee..6427ff0c7ecf 100644 --- a/sys/kern/kern_sysctl.c +++ b/sys/kern/kern_sysctl.c @@ -2765,12 +2765,12 @@ static void db_show_oid_name(int *oid, size_t nlen) { struct sysctl_oid *oidp; - int qoid[CTL_MAXNAME+2]; + int qoid[CTL_MAXNAME + 2]; int error; - qoid[0] = 0; + qoid[0] = CTL_SYSCTL; + qoid[1] = CTL_SYSCTL_NAME; memcpy(qoid + 2, oid, nlen * sizeof(int)); - qoid[1] = 1; error = sysctl_find_oid(qoid, nlen + 2, &oidp, NULL, NULL); if (error) @@ -2856,25 +2856,24 @@ static int db_show_sysctl_all(int *oid, size_t len, int flags) { struct sysctl_oid *oidp; - int name1[CTL_MAXNAME + 2], name2[CTL_MAXNAME + 2]; - size_t l1, l2; + int qoid[CTL_MAXNAME + 2], next[CTL_MAXNAME]; + size_t nlen; - name1[0] = CTL_SYSCTL; - name1[1] = CTL_SYSCTL_NEXT; - l1 = 2; + qoid[0] = CTL_SYSCTL; + qoid[1] = CTL_SYSCTL_NEXT; if (len) { - memcpy(name1 + 2, oid, len * sizeof(int)); - l1 += len; + nlen = len; + memcpy(&qoid[2], oid, nlen * sizeof(int)); } else { - name1[2] = CTL_KERN; - l1++; + nlen = 1; + qoid[2] = CTL_KERN; } for (;;) { - int i, error; + int error; + size_t nextsize = sizeof(next); - l2 = sizeof(name2); - error = kernel_sysctl(kdb_thread, name1, l1, - name2, &l2, NULL, 0, &l2, 0); + error = kernel_sysctl(kdb_thread, qoid, nlen + 2, + next, &nextsize, NULL, 0, &nlen, 0); if (error != 0) { if (error == ENOENT) return (0); @@ -2882,27 +2881,25 @@ db_show_sysctl_all(int *oid, size_t len, int flags) db_error("sysctl(next)"); } - l2 /= sizeof(int); + nlen /= sizeof(int); - if (l2 < (unsigned int)len) + if (nlen < (unsigned int)len) return (0); - for (i = 0; i < len; i++) - if (name2[i] != oid[i]) - return (0); + if (memcmp(&oid[0], &next[0], len * sizeof(int)) != 0) + return (0); /* Find the OID in question */ - error = sysctl_find_oid(name2, l2, &oidp, NULL, NULL); + error = sysctl_find_oid(next, nlen, &oidp, NULL, NULL); if (error) return (error); - i = db_show_oid(oidp, name2, l2, flags | DB_SYSCTL_SAFE_ONLY); + (void)db_show_oid(oidp, next, nlen, flags | DB_SYSCTL_SAFE_ONLY); if (db_pager_quit) return (0); - memcpy(name1+2, name2, l2 * sizeof(int)); - l1 = 2 + l2; + memcpy(&qoid[2 + len], &next[len], (nlen - len) * sizeof(int)); } }
