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mirror of https://git.FreeBSD.org/src.git synced 2024-12-05 09:14:03 +00:00

Introduce commandline caching in the kernel.

This fixes some nasty procfs problems for SMP, makes ps(1) run much faster,
and makes ps(1) even less dependent on /proc which will aid chroot and
jails alike.

To disable this facility and revert to previous behaviour:
        sysctl -w kern.ps_arg_cache_limit=0

For full details see the current@FreeBSD.org mail-archives.
This commit is contained in:
Poul-Henning Kamp 1999-11-16 20:31:58 +00:00
parent cf9e527008
commit b9df5231ca
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=53239
11 changed files with 171 additions and 3 deletions

View File

@ -520,7 +520,7 @@ saveuser(ki)
/*
* save arguments if needed
*/
if (needcomm && UREADOK(ki)) {
if (needcomm && (UREADOK(ki) || (KI_PROC(ki)->p_args != NULL))) {
ki->ki_args = fmt(kvm_getargv, ki, KI_PROC(ki)->p_comm,
MAXCOMLEN);
} else if (needcomm) {

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@ -29,6 +29,7 @@
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
/*
* Older FreeBSD 2.0, 2.1 and 2.2 had different ps_strings structures and
@ -74,6 +75,7 @@ setproctitle(fmt, va_alist)
va_list ap;
size_t len;
unsigned long ul_ps_strings;
int oid[4];
#if defined(__STDC__)
va_start(ap, fmt);
@ -103,6 +105,13 @@ setproctitle(fmt, va_alist)
va_end(ap);
/* Set the title into the kernel cached command line */
oid[0] = CTL_KERN;
oid[1] = KERN_PROC;
oid[2] = KERN_PROC_ARGS;
oid[3] = getpid();
sysctl(oid, 4, 0, 0, buf, strlen(buf) + 1);
if (ps_strings == NULL) {
len = sizeof(ul_ps_strings);
if (sysctlbyname("kern.ps_strings", &ul_ps_strings, &len, NULL,

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@ -33,6 +33,8 @@
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#if defined(LIBC_SCCS) && !defined(lint)
@ -666,6 +668,52 @@ kvm_getargv(kd, kp, nchr)
const struct kinfo_proc *kp;
int nchr;
{
int oid[4];
int i, l;
static int buflen;
static char *buf, *p;
static char **bufp;
static int argc;
if (!buflen) {
l = sizeof(buflen);
i = sysctlbyname("kern.ps_arg_cache_limit",
&buflen, &l, NULL, 0);
if (i == -1) {
buflen == 0;
} else {
buf = malloc(buflen);
if (buf == NULL)
buflen = 0;
argc = 32;
bufp = malloc(sizeof(char *) * argc);
}
}
if (buf != NULL) {
oid[0] = CTL_KERN;
oid[1] = KERN_PROC;
oid[2] = KERN_PROC_ARGS;
oid[3] = kp->kp_proc.p_pid;
l = buflen;
i = sysctl(oid, 4, buf, &l, 0, 0);
if (i == 0 && l > 0) {
i = 0;
p = buf;
do {
bufp[i++] = p;
p += strlen(p) + 1;
if (i >= argc) {
argc += argc;
bufp = realloc(bufp,
sizeof(char *) * argc);
}
} while (p < buf + l);
bufp[i++] = 0;
return (bufp);
}
}
if (kp->kp_proc.p_flag & P_SYSTEM)
return (NULL);
return (kvm_doargv(kd, kp, nchr, ps_str_a));
}

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@ -29,6 +29,7 @@
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
/*
* Older FreeBSD 2.0, 2.1 and 2.2 had different ps_strings structures and
@ -74,6 +75,7 @@ setproctitle(fmt, va_alist)
va_list ap;
size_t len;
unsigned long ul_ps_strings;
int oid[4];
#if defined(__STDC__)
va_start(ap, fmt);
@ -103,6 +105,13 @@ setproctitle(fmt, va_alist)
va_end(ap);
/* Set the title into the kernel cached command line */
oid[0] = CTL_KERN;
oid[1] = KERN_PROC;
oid[2] = KERN_PROC_ARGS;
oid[3] = getpid();
sysctl(oid, 4, 0, 0, buf, strlen(buf) + 1);
if (ps_strings == NULL) {
len = sizeof(ul_ps_strings);
if (sysctlbyname("kern.ps_strings", &ul_ps_strings, &len, NULL,

View File

@ -63,6 +63,8 @@
#include <machine/reg.h>
MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments");
static long *exec_copyout_strings __P((struct image_params *));
static long ps_strings = PS_STRINGS;
@ -71,6 +73,10 @@ SYSCTL_LONG(_kern, KERN_PS_STRINGS, ps_strings, CTLFLAG_RD, &ps_strings, "");
static long usrstack = USRSTACK;
SYSCTL_LONG(_kern, KERN_USRSTACK, usrstack, CTLFLAG_RD, &usrstack, "");
u_long ps_arg_cache_limit = PAGE_SIZE / 16;
SYSCTL_LONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW,
&ps_arg_cache_limit, "");
/*
* Each of the items is a pointer to a `const struct execsw', hence the
* double pointer here.
@ -316,6 +322,21 @@ execve(p, uap)
setregs(p, imgp->entry_addr, (u_long)(uintptr_t)stack_base,
imgp->ps_strings);
/* Free any previous argument cache */
if (p->p_args && --p->p_args->ar_ref == 0)
FREE(p->p_args, M_PARGS);
p->p_args = NULL;
/* Cache arguments if they fit inside our allowance */
i = imgp->endargs - imgp->stringbase;
if (ps_arg_cache_limit >= i + sizeof(struct pargs)) {
MALLOC(p->p_args, struct pargs *, sizeof(struct pargs) + i,
M_PARGS, M_WAITOK);
p->p_args->ar_ref = 1;
p->p_args->ar_length = i;
bcopy(imgp->stringbase, p->p_args->ar_args, i);
}
exec_fail_dealloc:
/*
@ -511,6 +532,8 @@ exec_extract_strings(imgp)
}
}
imgp->endargs = imgp->stringp;
/*
* extract environment strings
*/

View File

@ -493,6 +493,12 @@ wait1(q, uap, compat)
FREE(p->p_prison, M_PRISON);
}
/*
* Remove unused arguments
*/
if (p->p_args && --p->p_args->ar_ref == 0)
FREE(p->p_args, M_PARGS);
/*
* Finally finished with old proc entry.
* Unlink it from its process group and free it.

View File

@ -337,6 +337,9 @@ fork1(p1, flags, procp)
p2->p_flag |= P_JAILED;
}
if (p2->p_args)
p2->p_args->ar_ref++;
if (flags & RFSIGSHARE) {
p2->p_procsig = p1->p_procsig;
p2->p_procsig->ps_refcnt++;

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@ -38,8 +38,8 @@
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/filedesc.h>
#include <sys/tty.h>
#include <sys/signalvar.h>
@ -609,6 +609,57 @@ sysctl_kern_proc SYSCTL_HANDLER_ARGS
return (0);
}
/*
* This sysctl allows a process to retrieve the argument list or process
* title for another process without groping around in the address space
* of the other process. It also allow a process to set its own "process
* title to a string of its own choice.
*/
static int
sysctl_kern_proc_args SYSCTL_HANDLER_ARGS
{
int *name = (int*) arg1;
u_int namelen = arg2;
struct proc *p;
struct pargs *pa;
int error = 0;
if (namelen != 1)
return (EINVAL);
p = pfind((pid_t)name[0]);
if (!p)
return (0);
if (!PRISON_CHECK(curproc, p))
return (0);
if (req->newptr && curproc != p)
return (EPERM);
if (req->oldptr && p->p_args != NULL)
error = SYSCTL_OUT(req, p->p_args->ar_args, p->p_args->ar_length);
if (req->newptr == NULL)
return (error);
if (p->p_args && --p->p_args->ar_ref == 0)
FREE(p->p_args, M_PARGS);
p->p_args = NULL;
if (req->newlen + sizeof(struct pargs) > ps_arg_cache_limit)
return (error);
MALLOC(pa, struct pargs *, sizeof(struct pargs) + req->newlen,
M_PARGS, M_WAITOK);
pa->ar_ref = 1;
pa->ar_length = req->newlen;
error = SYSCTL_IN(req, pa->ar_args, req->newlen);
if (!error)
p->p_args = pa;
else
FREE(pa, M_PARGS);
return (error);
}
SYSCTL_NODE(_kern, KERN_PROC, proc, CTLFLAG_RD, 0, "Process table");
@ -629,3 +680,6 @@ SYSCTL_NODE(_kern_proc, KERN_PROC_RUID, ruid, CTLFLAG_RD,
SYSCTL_NODE(_kern_proc, KERN_PROC_PID, pid, CTLFLAG_RD,
sysctl_kern_proc, "Process table");
SYSCTL_NODE(_kern_proc, KERN_PROC_ARGS, args, CTLFLAG_RW,
sysctl_kern_proc_args, "Return process argument");

View File

@ -44,6 +44,7 @@ struct image_params {
const char *image_header; /* head of file to exec */
char *stringbase; /* base address of tmp string storage */
char *stringp; /* current 'end' pointer of tmp strings */
char *endargs; /* end of argv vector */
int stringspace; /* space left in tmp string storage area */
int argc, envc; /* count of argument and environment strings */
char *argv0; /* Replacement for argv[0] when interpreting */

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@ -97,6 +97,16 @@ struct pasleep {
int as_timo; /* Async timeout. */
};
/*
* pargs, used to hold a copy of the command line, if it had a sane
* length
*/
struct pargs {
u_int ar_ref; /* Reference count */
u_int ar_length; /* Length */
u_char ar_args[0]; /* Arguments */
};
/*
* Description of a process.
*
@ -211,7 +221,8 @@ struct proc {
struct sysentvec *p_sysent; /* System call dispatch information. */
struct rtprio p_rtprio; /* Realtime priority. */
struct prison *p_prison;
struct prison *p_prison;
struct pargs *p_args;
/* End area that is copied on creation. */
#define p_endcopy p_addr
struct user *p_addr; /* Kernel virtual addr of u-area (PROC ONLY). */
@ -299,6 +310,7 @@ struct pcred {
MALLOC_DECLARE(M_SESSION);
MALLOC_DECLARE(M_SUBPROC);
MALLOC_DECLARE(M_ZOMBIE);
MALLOC_DECLARE(M_PARGS);
#endif
/* flags for suser_xxx() */
@ -371,6 +383,8 @@ extern int whichqs; /* Bit mask summary of non-empty Q's. */
extern int whichrtqs; /* Bit mask summary of non-empty Q's. */
extern int whichidqs; /* Bit mask summary of non-empty Q's. */
extern u_long ps_arg_cache_limit;
struct proc *pfind __P((pid_t)); /* Find process by id. */
struct pgrp *pgfind __P((pid_t)); /* Find process group by id. */

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@ -317,6 +317,7 @@ void sysctl_unregister_oid(struct sysctl_oid *oidp);
#define KERN_PROC_TTY 4 /* by controlling tty */
#define KERN_PROC_UID 5 /* by effective uid */
#define KERN_PROC_RUID 6 /* by real uid */
#define KERN_PROC_ARGS 7 /* get/set arguments/proctitle */
/*
* KERN_IPC identifiers