Date: Mon, 30 Jan 2012 19:32:33 +0000 (UTC) From: Mikolaj Golub <trociny@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-9@freebsd.org Subject: svn commit: r230780 - stable/9/lib/libkvm Message-ID: <201201301932.q0UJWXLo099263@svn.freebsd.org>
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Author: trociny Date: Mon Jan 30 19:32:33 2012 New Revision: 230780 URL: http://svn.freebsd.org/changeset/base/230780 Log: MFC r227839, r230146: r227839: Now kvm_getenvv() and kvm_getargv() don't need procfs(5). r230146: In kvm_argv(), the case when the supplied buffer was too short to hold the requested value was handled incorrectly, and the function retuned NULL instead of the truncated result. Fix this and also remove unnecessary check for buf != NULL, which alway retuns true. Modified: stable/9/lib/libkvm/kvm_getprocs.3 stable/9/lib/libkvm/kvm_proc.c Directory Properties: stable/9/lib/libkvm/ (props changed) Modified: stable/9/lib/libkvm/kvm_getprocs.3 ============================================================================== --- stable/9/lib/libkvm/kvm_getprocs.3 Mon Jan 30 19:31:17 2012 (r230779) +++ stable/9/lib/libkvm/kvm_getprocs.3 Mon Jan 30 19:32:33 2012 (r230780) @@ -32,7 +32,7 @@ .\" @(#)kvm_getprocs.3 8.1 (Berkeley) 6/4/93 .\" $FreeBSD$ .\" -.Dd September 27, 2003 +.Dd November 22, 2011 .Dt KVM_GETPROCS 3 .Os .Sh NAME @@ -172,10 +172,3 @@ on failure. .Xr kvm_write 3 .Sh BUGS These routines do not belong in the kvm interface. -.Pp -In order for -.Xr kvm_getenvv 3 -to function correctly, -.Xr procfs 5 -must be mounted on -.Pa /proc . Modified: stable/9/lib/libkvm/kvm_proc.c ============================================================================== --- stable/9/lib/libkvm/kvm_proc.c Mon Jan 30 19:31:17 2012 (r230779) +++ stable/9/lib/libkvm/kvm_proc.c Mon Jan 30 19:32:33 2012 (r230780) @@ -72,9 +72,6 @@ __FBSDID("$FreeBSD$"); #include <nlist.h> #include <kvm.h> -#include <vm/vm.h> -#include <vm/vm_param.h> - #include <sys/sysctl.h> #include <limits.h> @@ -623,276 +620,16 @@ _kvm_realloc(kvm_t *kd, void *p, size_t return (np); } -#ifndef MAX -#define MAX(a, b) ((a) > (b) ? (a) : (b)) -#endif - -/* - * Read in an argument vector from the user address space of process kp. - * addr if the user-space base address of narg null-terminated contiguous - * strings. This is used to read in both the command arguments and - * environment strings. Read at most maxcnt characters of strings. - */ -static char ** -kvm_argv(kvm_t *kd, const struct kinfo_proc *kp, u_long addr, int narg, - int maxcnt) -{ - char *np, *cp, *ep, *ap; - u_long oaddr = -1; - int len, cc; - char **argv; - - /* - * Check that there aren't an unreasonable number of arguments, - * and that the address is in user space. Special test for - * VM_MIN_ADDRESS as it evaluates to zero, but is not a simple zero - * constant for some archs. We cannot use the pre-processor here and - * for some archs the compiler would trigger a signedness warning. - */ - if (narg > 512 || addr + 1 < VM_MIN_ADDRESS + 1 || addr >= VM_MAXUSER_ADDRESS) - return (0); - - /* - * kd->argv : work space for fetching the strings from the target - * process's space, and is converted for returning to caller - */ - if (kd->argv == 0) { - /* - * Try to avoid reallocs. - */ - kd->argc = MAX(narg + 1, 32); - kd->argv = (char **)_kvm_malloc(kd, kd->argc * - sizeof(*kd->argv)); - if (kd->argv == 0) - return (0); - } else if (narg + 1 > kd->argc) { - kd->argc = MAX(2 * kd->argc, narg + 1); - kd->argv = (char **)_kvm_realloc(kd, kd->argv, kd->argc * - sizeof(*kd->argv)); - if (kd->argv == 0) - return (0); - } - /* - * kd->argspc : returned to user, this is where the kd->argv - * arrays are left pointing to the collected strings. - */ - if (kd->argspc == 0) { - kd->argspc = (char *)_kvm_malloc(kd, PAGE_SIZE); - if (kd->argspc == 0) - return (0); - kd->arglen = PAGE_SIZE; - } - /* - * kd->argbuf : used to pull in pages from the target process. - * the strings are copied out of here. - */ - if (kd->argbuf == 0) { - kd->argbuf = (char *)_kvm_malloc(kd, PAGE_SIZE); - if (kd->argbuf == 0) - return (0); - } - - /* Pull in the target process'es argv vector */ - cc = sizeof(char *) * narg; - if (kvm_uread(kd, kp, addr, (char *)kd->argv, cc) != cc) - return (0); - /* - * ap : saved start address of string we're working on in kd->argspc - * np : pointer to next place to write in kd->argspc - * len: length of data in kd->argspc - * argv: pointer to the argv vector that we are hunting around the - * target process space for, and converting to addresses in - * our address space (kd->argspc). - */ - ap = np = kd->argspc; - argv = kd->argv; - len = 0; - /* - * Loop over pages, filling in the argument vector. - * Note that the argv strings could be pointing *anywhere* in - * the user address space and are no longer contiguous. - * Note that *argv is modified when we are going to fetch a string - * that crosses a page boundary. We copy the next part of the string - * into to "np" and eventually convert the pointer. - */ - while (argv < kd->argv + narg && *argv != 0) { - - /* get the address that the current argv string is on */ - addr = (u_long)*argv & ~(PAGE_SIZE - 1); - - /* is it the same page as the last one? */ - if (addr != oaddr) { - if (kvm_uread(kd, kp, addr, kd->argbuf, PAGE_SIZE) != - PAGE_SIZE) - return (0); - oaddr = addr; - } - - /* offset within the page... kd->argbuf */ - addr = (u_long)*argv & (PAGE_SIZE - 1); - - /* cp = start of string, cc = count of chars in this chunk */ - cp = kd->argbuf + addr; - cc = PAGE_SIZE - addr; - - /* dont get more than asked for by user process */ - if (maxcnt > 0 && cc > maxcnt - len) - cc = maxcnt - len; - - /* pointer to end of string if we found it in this page */ - ep = memchr(cp, '\0', cc); - if (ep != 0) - cc = ep - cp + 1; - /* - * at this point, cc is the count of the chars that we are - * going to retrieve this time. we may or may not have found - * the end of it. (ep points to the null if the end is known) - */ - - /* will we exceed the malloc/realloced buffer? */ - if (len + cc > kd->arglen) { - int off; - char **pp; - char *op = kd->argspc; - - kd->arglen *= 2; - kd->argspc = (char *)_kvm_realloc(kd, kd->argspc, - kd->arglen); - if (kd->argspc == 0) - return (0); - /* - * Adjust argv pointers in case realloc moved - * the string space. - */ - off = kd->argspc - op; - for (pp = kd->argv; pp < argv; pp++) - *pp += off; - ap += off; - np += off; - } - /* np = where to put the next part of the string in kd->argspc*/ - /* np is kinda redundant.. could use "kd->argspc + len" */ - memcpy(np, cp, cc); - np += cc; /* inc counters */ - len += cc; - - /* - * if end of string found, set the *argv pointer to the - * saved beginning of string, and advance. argv points to - * somewhere in kd->argv.. This is initially relative - * to the target process, but when we close it off, we set - * it to point in our address space. - */ - if (ep != 0) { - *argv++ = ap; - ap = np; - } else { - /* update the address relative to the target process */ - *argv += cc; - } - - if (maxcnt > 0 && len >= maxcnt) { - /* - * We're stopping prematurely. Terminate the - * current string. - */ - if (ep == 0) { - *np = '\0'; - *argv++ = ap; - } - break; - } - } - /* Make sure argv is terminated. */ - *argv = 0; - return (kd->argv); -} - -static void -ps_str_a(struct ps_strings *p, u_long *addr, int *n) -{ - *addr = (u_long)p->ps_argvstr; - *n = p->ps_nargvstr; -} - -static void -ps_str_e (struct ps_strings *p, u_long *addr, int *n) -{ - *addr = (u_long)p->ps_envstr; - *n = p->ps_nenvstr; -} - /* - * Determine if the proc indicated by p is still active. - * This test is not 100% foolproof in theory, but chances of - * being wrong are very low. + * Get the command args or environment. */ -static int -proc_verify(const struct kinfo_proc *curkp) -{ - struct kinfo_proc newkp; - int mib[4]; - size_t len; - - mib[0] = CTL_KERN; - mib[1] = KERN_PROC; - mib[2] = KERN_PROC_PID; - mib[3] = curkp->ki_pid; - len = sizeof(newkp); - if (sysctl(mib, 4, &newkp, &len, NULL, 0) == -1) - return (0); - return (curkp->ki_pid == newkp.ki_pid && - (newkp.ki_stat != SZOMB || curkp->ki_stat == SZOMB)); -} - static char ** -kvm_doargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr, - void (*info)(struct ps_strings *, u_long *, int *)) -{ - char **ap; - u_long addr; - int cnt; - static struct ps_strings arginfo; - static u_long ps_strings; - size_t len; - - if (ps_strings == 0) { - len = sizeof(ps_strings); - if (sysctlbyname("kern.ps_strings", &ps_strings, &len, NULL, - 0) == -1) - ps_strings = PS_STRINGS; - } - - /* - * Pointers are stored at the top of the user stack. - */ - if (kp->ki_stat == SZOMB || - kvm_uread(kd, kp, ps_strings, (char *)&arginfo, - sizeof(arginfo)) != sizeof(arginfo)) - return (0); - - (*info)(&arginfo, &addr, &cnt); - if (cnt == 0) - return (0); - ap = kvm_argv(kd, kp, addr, cnt, nchr); - /* - * For live kernels, make sure this process didn't go away. - */ - if (ap != 0 && ISALIVE(kd) && !proc_verify(kp)) - ap = 0; - return (ap); -} - -/* - * Get the command args. This code is now machine independent. - */ -char ** -kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) +kvm_argv(kvm_t *kd, const struct kinfo_proc *kp, int env, int nchr) { int oid[4]; int i; size_t bufsz; - static unsigned long buflen; + static int buflen; static char *buf, *p; static char **bufp; static int argc; @@ -903,102 +640,66 @@ kvm_getargv(kvm_t *kd, const struct kinf return (0); } - if (!buflen) { - bufsz = sizeof(buflen); - i = sysctlbyname("kern.ps_arg_cache_limit", - &buflen, &bufsz, 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->ki_pid; - bufsz = buflen; - i = sysctl(oid, 4, buf, &bufsz, 0, 0); - if (i == 0 && bufsz > 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 + bufsz); - bufp[i++] = 0; - return (bufp); - } + if (nchr == 0 || nchr > ARG_MAX) + nchr = ARG_MAX; + if (buflen == 0) { + buf = malloc(nchr); + if (buf == NULL) { + _kvm_err(kd, kd->program, "cannot allocate memory"); + return (0); + } + buflen = nchr; + argc = 32; + bufp = malloc(sizeof(char *) * argc); + } else if (nchr > buflen) { + p = realloc(buf, nchr); + if (p != NULL) { + buf = p; + buflen = nchr; + } + } + oid[0] = CTL_KERN; + oid[1] = KERN_PROC; + oid[2] = env ? KERN_PROC_ENV : KERN_PROC_ARGS; + oid[3] = kp->ki_pid; + bufsz = buflen; + if (sysctl(oid, 4, buf, &bufsz, 0, 0) == -1) { + /* + * If the supplied buf is too short to hold the requested + * value the sysctl returns with ENOMEM. The buf is filled + * with the truncated value and the returned bufsz is equal + * to the requested len. + */ + if (errno != ENOMEM || bufsz != (size_t)buflen) + return (0); + buf[bufsz - 1] = '\0'; + errno = 0; + } else if (bufsz == 0) { + return (0); } - if (kp->ki_flag & P_SYSTEM) - return (NULL); - return (kvm_doargv(kd, kp, nchr, ps_str_a)); + 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 + bufsz); + bufp[i++] = 0; + return (bufp); } char ** -kvm_getenvv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) +kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) { - return (kvm_doargv(kd, kp, nchr, ps_str_e)); + return (kvm_argv(kd, kp, 0, nchr)); } -/* - * Read from user space. The user context is given by p. - */ -ssize_t -kvm_uread(kvm_t *kd, const struct kinfo_proc *kp, u_long uva, char *buf, - size_t len) +char ** +kvm_getenvv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) { - char *cp; - char procfile[MAXPATHLEN]; - ssize_t amount; - int fd; - - if (!ISALIVE(kd)) { - _kvm_err(kd, kd->program, - "cannot read user space from dead kernel"); - return (0); - } - - sprintf(procfile, "/proc/%d/mem", kp->ki_pid); - fd = open(procfile, O_RDONLY, 0); - if (fd < 0) { - _kvm_err(kd, kd->program, "cannot open %s", procfile); - return (0); - } - - cp = buf; - while (len > 0) { - errno = 0; - if (lseek(fd, (off_t)uva, 0) == -1 && errno != 0) { - _kvm_err(kd, kd->program, "invalid address (%lx) in %s", - uva, procfile); - break; - } - amount = read(fd, cp, len); - if (amount < 0) { - _kvm_syserr(kd, kd->program, "error reading %s", - procfile); - break; - } - if (amount == 0) { - _kvm_err(kd, kd->program, "EOF reading %s", procfile); - break; - } - cp += amount; - uva += amount; - len -= amount; - } - - close(fd); - return ((ssize_t)(cp - buf)); + return (kvm_argv(kd, kp, 1, nchr)); }
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