From ff78355bc11257744759b5005d330e4a7583a4e4 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Mon, 19 May 2014 11:19:49 -0400 Subject: rework sysconf table to treat zero entries as invalid MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit based on patch by Timo Teräs. previously, the value zero was used as a literal zero, meaning that all invalid sysconf "names", which should result in sysconf returning -1, had to be explicitly listed. (in addition, it was not possible for sysconf to set errno to EINVAL, as there was no distinction between -1 as an error and -1 as a valid result.) now, the value 0 is used for invalid/undefined slots in the table and a new switch table entry is used for returning literal zeros. in addition, an off-by-one error in checking against the table size is fixed. --- src/conf/sysconf.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/src/conf/sysconf.c b/src/conf/sysconf.c index bf433d6b..136bc1d9 100644 --- a/src/conf/sysconf.c +++ b/src/conf/sysconf.c @@ -17,6 +17,7 @@ #define JT_NPROCESSORS_ONLN JT(7) #define JT_PHYS_PAGES JT(8) #define JT_AVPHYS_PAGES JT(9) +#define JT_ZERO JT(10) #define RLIM(x) (-32768|(RLIMIT_ ## x)) @@ -48,7 +49,7 @@ long sysconf(int name) [_SC_SHARED_MEMORY_OBJECTS] = VER, [_SC_AIO_LISTIO_MAX] = -1, [_SC_AIO_MAX] = -1, - [_SC_AIO_PRIO_DELTA_MAX] = 0, /* ?? */ + [_SC_AIO_PRIO_DELTA_MAX] = JT_ZERO, /* ?? */ [_SC_DELAYTIMER_MAX] = _POSIX_DELAYTIMER_MAX, [_SC_MQ_OPEN_MAX] = -1, [_SC_MQ_PRIO_MAX] = JT_MQ_PRIO_MAX, @@ -149,8 +150,8 @@ long sysconf(int name) [_SC_NL_SETMAX] = -1, [_SC_NL_TEXTMAX] = -1, [_SC_XBS5_ILP32_OFF32] = -1, - [_SC_XBS5_ILP32_OFFBIG] = 2*(sizeof(long)==4)-1, - [_SC_XBS5_LP64_OFF64] = 2*(sizeof(long)==8)-1, + [_SC_XBS5_ILP32_OFFBIG] = sizeof(long)==4 ? 1 : JT_ZERO, + [_SC_XBS5_LP64_OFF64] = sizeof(long)==8 ? 1 : JT_ZERO, [_SC_XBS5_LPBIG_OFFBIG] = -1, [_SC_XOPEN_LEGACY] = -1, [_SC_XOPEN_REALTIME] = -1, @@ -197,11 +198,11 @@ long sysconf(int name) [_SC_2_PBS_MESSAGE] = -1, [_SC_2_PBS_TRACK] = -1, [_SC_SYMLOOP_MAX] = SYMLOOP_MAX, - [_SC_STREAMS] = 0, + [_SC_STREAMS] = JT_ZERO, [_SC_2_PBS_CHECKPOINT] = -1, [_SC_V6_ILP32_OFF32] = -1, - [_SC_V6_ILP32_OFFBIG] = 2*(sizeof(long)==4)-1, - [_SC_V6_LP64_OFF64] = 2*(sizeof(long)==8)-1, + [_SC_V6_ILP32_OFFBIG] = sizeof(long)==4 ? 1 : JT_ZERO, + [_SC_V6_LP64_OFF64] = sizeof(long)==8 ? 1 : JT_ZERO, [_SC_V6_LPBIG_OFFBIG] = -1, [_SC_HOST_NAME_MAX] = HOST_NAME_MAX, [_SC_TRACE] = -1, @@ -212,20 +213,20 @@ long sysconf(int name) [_SC_IPV6] = VER, [_SC_RAW_SOCKETS] = VER, [_SC_V7_ILP32_OFF32] = -1, - [_SC_V7_ILP32_OFFBIG] = 2*(sizeof(long)==4)-1, - [_SC_V7_LP64_OFF64] = 2*(sizeof(long)==8)-1, + [_SC_V7_ILP32_OFFBIG] = sizeof(long)==4 ? 1 : JT_ZERO, + [_SC_V7_LP64_OFF64] = sizeof(long)==8 ? 1 : JT_ZERO, [_SC_V7_LPBIG_OFFBIG] = -1, [_SC_SS_REPL_MAX] = -1, [_SC_TRACE_EVENT_NAME_MAX] = -1, [_SC_TRACE_NAME_MAX] = -1, [_SC_TRACE_SYS_MAX] = -1, [_SC_TRACE_USER_EVENT_MAX] = -1, - [_SC_XOPEN_STREAMS] = 0, + [_SC_XOPEN_STREAMS] = JT_ZERO, [_SC_THREAD_ROBUST_PRIO_INHERIT] = -1, [_SC_THREAD_ROBUST_PRIO_PROTECT] = -1, }; - if (name > sizeof(values)/sizeof(values[0])) { + if (name >= sizeof(values)/sizeof(values[0]) || !values[name]) { errno = EINVAL; return -1; } else if (values[name] >= -1) { @@ -267,6 +268,8 @@ long sysconf(int name) mem *= si.mem_unit; mem /= PAGE_SIZE; return (mem > LONG_MAX) ? LONG_MAX : mem; + case JT_ZERO & 255: + return 0; } return values[name]; } -- cgit v1.2.1