procps/proc/sig.c
Olof Sivertsson 586bfb7655 kill: Fix free() with bad pointer on SIG-prefixed signal-name
kill -l SIGHUP (or any other signal-name prefixed with "SIG")
would cause free() to be called with a bad pointer instead of
a pointer to what was allocated. Fix this and add test-case.
2016-09-08 22:32:18 +02:00

297 lines
7.7 KiB
C

/*
* sig.c - signal name, and number, conversions
* Copyright 1998-2003 by Albert Cahalan
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <ctype.h>
#include <signal.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include "sig.h"
#include "c.h"
/* Linux signals:
*
* SIGSYS is required by Unix98.
* SIGEMT is part of SysV, BSD, and ancient UNIX tradition.
*
* They are provided by these Linux ports: alpha, mips, sparc, and sparc64.
* You get SIGSTKFLT and SIGUNUSED instead on i386, m68k, ppc, and arm.
* (this is a Linux & libc bug -- both must be fixed)
*
* Total garbage: SIGIO SIGINFO SIGIOT SIGLOST SIGCLD
* (popular ones are handled as aliases)
* Nearly garbage: SIGSTKFLT SIGUNUSED (nothing else to fill slots)
*/
/* Linux 2.3.29 replaces SIGUNUSED with the standard SIGSYS signal */
#ifndef SIGSYS
# warning Standards require that <signal.h> define SIGSYS
# define SIGSYS SIGUNUSED
#endif
/* If we see both, it is likely SIGSTKFLT (junk) was replaced. */
#ifdef SIGEMT
# undef SIGSTKFLT
#endif
#ifndef SIGRTMIN
# warning Standards require that <signal.h> define SIGRTMIN; assuming 32
# define SIGRTMIN 32
#endif
/* It seems the SPARC libc does not know the kernel supports SIGPWR. */
#if defined(__linux__) && !defined(SIGPWR)
# warning Your header files lack SIGPWR. (assuming it is number 29)
# define SIGPWR 29
#endif
typedef struct mapstruct {
const char *name;
int num;
} mapstruct;
static const mapstruct sigtable[] = {
{"ABRT", SIGABRT}, /* IOT */
{"ALRM", SIGALRM},
{"BUS", SIGBUS},
{"CHLD", SIGCHLD}, /* CLD */
{"CONT", SIGCONT},
#ifdef SIGEMT
{"EMT", SIGEMT},
#endif
{"FPE", SIGFPE},
{"HUP", SIGHUP},
{"ILL", SIGILL},
{"INT", SIGINT},
{"KILL", SIGKILL},
{"PIPE", SIGPIPE},
{"POLL", SIGPOLL}, /* IO */
{"PROF", SIGPROF},
#ifdef SIGPWR
{"PWR", SIGPWR},
#endif
{"QUIT", SIGQUIT},
{"SEGV", SIGSEGV},
#ifdef SIGSTKFLT
{"STKFLT", SIGSTKFLT},
#endif
{"STOP", SIGSTOP},
{"SYS", SIGSYS}, /* UNUSED */
{"TERM", SIGTERM},
{"TRAP", SIGTRAP},
{"TSTP", SIGTSTP},
{"TTIN", SIGTTIN},
{"TTOU", SIGTTOU},
{"URG", SIGURG},
{"USR1", SIGUSR1},
{"USR2", SIGUSR2},
{"VTALRM", SIGVTALRM},
{"WINCH", SIGWINCH},
{"XCPU", SIGXCPU},
{"XFSZ", SIGXFSZ}
};
static const int number_of_signals = sizeof(sigtable)/sizeof(mapstruct);
static int compare_signal_names(const void *a, const void *b){
return strcasecmp( ((const mapstruct*)a)->name, ((const mapstruct*)b)->name );
}
/* return -1 on failure */
int signal_name_to_number(const char *restrict name){
long val;
int offset;
/* clean up name */
if(!strncasecmp(name,"SIG",3)) name += 3;
if(!strcasecmp(name,"CLD")) return SIGCHLD;
if(!strcasecmp(name,"IO")) return SIGPOLL;
if(!strcasecmp(name,"IOT")) return SIGABRT;
/* search the table */
{
const mapstruct ms = {name,0};
const mapstruct *restrict const ptr = bsearch(
&ms,
sigtable,
number_of_signals,
sizeof(mapstruct),
compare_signal_names
);
if(ptr) return ptr->num;
}
if(!strcasecmp(name,"RTMIN")) return SIGRTMIN;
if(!strcasecmp(name,"EXIT")) return 0;
if(!strcasecmp(name,"NULL")) return 0;
offset = 0;
if(!strncasecmp(name,"RTMIN+",6)){
name += 6;
offset = SIGRTMIN;
}
/* not found, so try as a number */
{
char *endp;
val = strtol(name,&endp,10);
if(*endp || endp==name) return -1; /* not valid */
}
if(val+SIGRTMIN>127) return -1; /* not valid */
return val+offset;
}
const char *signal_number_to_name(int signo){
static char buf[32];
int n = number_of_signals;
signo &= 0x7f; /* need to process exit values too */
while(n--){
if(sigtable[n].num==signo) return sigtable[n].name;
}
if(signo == SIGRTMIN) return "RTMIN";
if(signo) sprintf(buf, "RTMIN+%d", signo-SIGRTMIN);
else strcpy(buf,"0"); /* AIX has NULL; Solaris has EXIT */
return buf;
}
int print_given_signals(int argc, const char *restrict const *restrict argv, int max_line){
char buf[1280]; /* 128 signals, "RTMIN+xx" is largest */
int ret = 0; /* to be used as exit code by caller */
int place = 0; /* position on this line */
int amt;
if(argc > 128) return 1;
while(argc--){
char tmpbuf[16];
const char *restrict const txt = *argv;
if(*txt >= '0' && *txt <= '9'){
long val;
char *endp;
val = strtol(txt,&endp,10);
if(*endp){
fprintf(stderr, "Signal \"%s\" not known.\n", txt);
ret = 1;
goto end;
}
amt = sprintf(tmpbuf, "%s", signal_number_to_name(val));
}else{
int sno;
sno = signal_name_to_number(txt);
if(sno == -1){
fprintf(stderr, "Signal \"%s\" not known.\n", txt);
ret = 1;
goto end;
}
amt = sprintf(tmpbuf, "%d", sno);
}
if(!place){
strcpy(buf,tmpbuf);
place = amt;
goto end;
}
if(amt+place+1 > max_line){
printf("%s\n", buf);
strcpy(buf,tmpbuf);
place = amt;
goto end;
}
sprintf(buf+place, " %s", tmpbuf);
place += amt+1;
end:
argv++;
}
if(place) printf("%s\n", buf);
return ret;
}
/* strtosig is similar to print_given_signals() with exception, that
* this function takes a string, and converts it to a signal name or
* a number string depending on which way a round conversion is
* queried. Non-existing signals return NULL. Notice that the
* returned string should be freed after use.
*/
char *strtosig(const char *restrict s){
char *converted = NULL, *copy, *p, *endp;
int i, numsignal = 0;
copy = strdup(s);
if (!copy)
xerrx(EXIT_FAILURE, "cannot duplicate string");
for (p = copy; *p != '\0'; p++)
*p = toupper(*p);
p = copy;
if (p[0] == 'S' && p[1] == 'I' && p[2] == 'G')
p += 3;
if (isdigit(*p)){
numsignal = strtol(s,&endp,10);
if(*endp || endp==s) return NULL; /* not valid */
}
if (numsignal){
for (i = 0; i < number_of_signals; i++){
if (numsignal == sigtable[i].num){
converted = strdup(sigtable[i].name);
break;
}
}
} else {
for (i = 0; i < number_of_signals; i++){
if (strcmp(p, sigtable[i].name) == 0){
converted = malloc(sizeof(char) * 8);
if (converted)
snprintf(converted, sizeof(converted) - 1, "%d", sigtable[i].num);
break;
}
}
}
free(copy);
return converted;
}
void pretty_print_signals(void){
int i = 0;
while(++i <= number_of_signals){
int n;
n = printf("%2d %s", i, signal_number_to_name(i));
if(n>0 && i%7) printf("%s", " \0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" + n);
else printf("\n");
}
if((i-1)%7) printf("\n");
}
void unix_print_signals(void){
int pos = 0;
int i = 0;
while(++i <= number_of_signals){
if(i-1) printf("%c", (pos>73)?(pos=0,'\n'):(pos++,' ') );
pos += printf("%s", signal_number_to_name(i));
}
printf("\n");
}
/* sanity check */
static int init_signal_list(void) __attribute__((constructor));
static int init_signal_list(void){
if(number_of_signals != 31){
fprintf(stderr, "WARNING: %d signals -- adjust and recompile.\n", number_of_signals);
}
return 0;
}