Date: Fri, 24 Jul 2009 19:12:20 +0000 (UTC) From: Brooks Davis <brooks@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r195853 - in head: sys/kern sys/sys usr.bin/procstat Message-ID: <200907241912.n6OJCKih018651@svn.freebsd.org>
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Author: brooks Date: Fri Jul 24 19:12:19 2009 New Revision: 195853 URL: http://svn.freebsd.org/changeset/base/195853 Log: Introduce a new sysctl process mib, kern.proc.groups which adds the ability to retrieve the group list of each process. Modify procstat's -s option to query this mib when the kinfo_proc reports that the field has been truncated. If the mib does not exist, fall back to the truncated list. Reviewed by: rwatson Approved by: re (kib) MFC after: 2 weeks Modified: head/sys/kern/kern_proc.c head/sys/sys/sysctl.h head/usr.bin/procstat/procstat_cred.c Modified: head/sys/kern/kern_proc.c ============================================================================== --- head/sys/kern/kern_proc.c Fri Jul 24 18:31:04 2009 (r195852) +++ head/sys/kern/kern_proc.c Fri Jul 24 19:12:19 2009 (r195853) @@ -1826,6 +1826,43 @@ repeat: } #endif +/* + * This sysctl allows a process to retrieve the full list of groups from + * itself or another process. + */ +static int +sysctl_kern_proc_groups(SYSCTL_HANDLER_ARGS) +{ + pid_t *pidp = (pid_t *)arg1; + unsigned int arglen = arg2; + struct proc *p; + struct ucred *cred; + int error; + + if (arglen != 1) + return (EINVAL); + if (*pidp == -1) { /* -1 means this process */ + p = req->td->td_proc; + } else { + p = pfind(*pidp); + if (p == NULL) + return (ESRCH); + if ((error = p_cansee(curthread, p)) != 0) { + PROC_UNLOCK(p); + return (error); + } + } + + cred = crhold(p->p_ucred); + if (*pidp != -1) + PROC_UNLOCK(p); + + error = SYSCTL_OUT(req, cred->cr_groups, + cred->cr_ngroups * sizeof(gid_t)); + crfree(cred); + return (error); +} + SYSCTL_NODE(_kern, KERN_PROC, proc, CTLFLAG_RD, 0, "Process table"); SYSCTL_PROC(_kern_proc, KERN_PROC_ALL, all, CTLFLAG_RD|CTLTYPE_STRUCT| @@ -1910,3 +1947,6 @@ static SYSCTL_NODE(_kern_proc, KERN_PROC static SYSCTL_NODE(_kern_proc, KERN_PROC_KSTACK, kstack, CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_kern_proc_kstack, "Process kernel stacks"); #endif + +static SYSCTL_NODE(_kern_proc, KERN_PROC_GROUPS, groups, CTLFLAG_RD | + CTLFLAG_MPSAFE, sysctl_kern_proc_groups, "Process groups"); Modified: head/sys/sys/sysctl.h ============================================================================== --- head/sys/sys/sysctl.h Fri Jul 24 18:31:04 2009 (r195852) +++ head/sys/sys/sysctl.h Fri Jul 24 19:12:19 2009 (r195853) @@ -486,6 +486,7 @@ TAILQ_HEAD(sysctl_ctx_list, sysctl_ctx_e */ #define KERN_PROC_VMMAP 32 /* VM map entries for process */ #define KERN_PROC_FILEDESC 33 /* File descriptors for process */ +#define KERN_PROC_GROUPS 34 /* process groups */ /* * KERN_IPC identifiers Modified: head/usr.bin/procstat/procstat_cred.c ============================================================================== --- head/usr.bin/procstat/procstat_cred.c Fri Jul 24 18:31:04 2009 (r195852) +++ head/usr.bin/procstat/procstat_cred.c Fri Jul 24 19:12:19 2009 (r195853) @@ -31,7 +31,9 @@ #include <sys/user.h> #include <err.h> +#include <stdlib.h> #include <stdio.h> +#include <unistd.h> #include "procstat.h" @@ -39,6 +41,10 @@ void procstat_cred(pid_t pid, struct kinfo_proc *kipp) { int i; + int mib[4]; + int ngroups; + size_t len; + gid_t *groups = NULL; if (!hflag) printf("%5s %-16s %5s %5s %5s %5s %5s %5s %-20s\n", "PID", @@ -53,7 +59,39 @@ procstat_cred(pid_t pid, struct kinfo_pr printf("%5d ", kipp->ki_groups[0]); printf("%5d ", kipp->ki_rgid); printf("%5d ", kipp->ki_svgid); - for (i = 0; i < kipp->ki_ngroups; i++) - printf("%s%d", (i > 0) ? "," : "", kipp->ki_groups[i]); + + /* + * We may have too many groups to fit in kinfo_proc's statically + * sized storage. If that occurs, attempt to retrieve them via + * sysctl. + */ + if (kipp->ki_cr_flags & KI_CRF_GRP_OVERFLOW) { + mib[0] = CTL_KERN; + mib[1] = KERN_PROC; + mib[2] = KERN_PROC_GROUPS; + mib[3] = pid; + + ngroups = sysconf(_SC_NGROUPS_MAX) + 1; + len = ngroups * sizeof(gid_t); + if((groups = malloc(len)) == NULL) + err(-1, "malloc"); + + if (sysctl(mib, 4, groups, &len, NULL, 0) == -1) { + warn("sysctl: kern.proc.groups: %d " + "group list truncated", pid); + free(groups); + groups = NULL; + } + ngroups = len / sizeof(gid_t); + } + if (groups == NULL) { + ngroups = kipp->ki_ngroups; + groups = kipp->ki_groups; + } + for (i = 0; i < ngroups; i++) + printf("%s%d", (i > 0) ? "," : "", groups[i]); + if (groups != kipp->ki_groups) + free(groups); + printf("\n"); }
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