fix race condition

This commit is contained in:
albert 2005-06-10 15:43:15 +00:00
parent cd80f609e6
commit 864a5356a1
5 changed files with 27 additions and 5 deletions

1
NEWS
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@ -1,6 +1,7 @@
procps-3.2.5 --> procps-3.2.6
more MIPS crud -- thanks Jim Gifford and Ryan Oliver
begin prep for setuid
procps-3.2.4 --> procps-3.2.5

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@ -509,8 +509,10 @@ int open_psdb_message(const char *restrict override, void (*message)(const char
||
(sm=getenv("PS_SYSTEM_MAP"))
){
read_and_parse();
if(sysmap_mmap(sm, message)) return 0;
if(!have_privs){
read_and_parse();
if(sysmap_mmap(sm, message)) return 0;
}
/* failure is better than ignoring the user & using bad data */
return -1; /* ought to return "Namelist not found." */
}

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@ -1,7 +1,7 @@
# for --version-script
# WTF is the syntax for this file?
# Give me a BNF, man!
_3_2_4 {
_3_2_5 {
global:
__cyg_profile_func_enter; __cyg_profile_func_exit; main;
@ -10,7 +10,7 @@ global:
openproc; closeproc;
tty_to_dev; dev_to_tty; open_psdb_message; open_psdb; lookup_wchan;
display_version; procps_version; linux_version_code;
Hertz; smp_num_cpus;
Hertz; smp_num_cpus; have_privs;
sprint_uptime; uptime; user_from_uid; print_uptime; loadavg;
pretty_print_signals; print_given_signals; unix_print_signals; signal_name_to_number; signal_number_to_name;
meminfo; vminfo; getstat; getdiskstat; getpartitions_num; getslabinfo; get_pid_digits;

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@ -170,8 +170,13 @@ static void old_Hertz_hack(void){
}
}
// same as: euid != uid || egid != gid
#ifndef AT_SECURE
#define AT_SECURE 23 // secure mode boolean (true if setuid, etc.)
#endif
#ifndef AT_CLKTCK
#define AT_CLKTCK 17 /* frequency of times() */
#define AT_CLKTCK 17 // frequency of times()
#endif
#define NOTE_NOT_FOUND 42
@ -189,8 +194,21 @@ static unsigned long find_elf_note(unsigned long findme){
return NOTE_NOT_FOUND;
}
int have_privs;
static int check_for_privs(void){
unsigned long rc = find_elf_note(AT_SECURE);
if(rc==NOTE_NOT_FOUND){
// not valid to run this code after UID or GID change!
// (if needed, may use AT_UID and friends instead)
rc = geteuid() != getuid() || getegid() != getgid();
}
return !!rc;
}
static void init_libproc(void) __attribute__((constructor));
static void init_libproc(void){
have_privs = check_for_privs();
// ought to count CPUs in /proc/stat instead of relying
// on glibc, which foolishly tries to parse /proc/cpuinfo
//

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@ -8,6 +8,7 @@ EXTERN_C_BEGIN
extern unsigned long long Hertz; /* clock tick frequency */
extern long smp_num_cpus; /* number of CPUs */
extern int have_privs; /* boolean, true if setuid or similar */
#if 0
#define JT double