When an application documents that it responds such and such to SIGRTMIN+n, that almost always means with respect to the libc-provided SIGRTMIN. Hence I disagree with the "more correct" in commit 7b276fc17594. In any case, this is rather unfortunate:
# kill -l RTMIN+2 36 # busybox kill -l RTMIN+2 34 (the first shell is bash). We probably can't change default behaviour after 7 years, but at least we can provide a config option. We avoid a little code generation (repeated calls to __libc_current_sigrtmin) by stashing SIGRTMIN/SIGRTMAX in local variables, but it does cost ~50 bytes. The next patch serves as penance for that. Signed-off-by: Rasmus Villemoes <[email protected]> --- libbb/u_signal_names.c | 49 ++++++++++++++++++++++++++++++++++++------------- 1 file changed, 36 insertions(+), 13 deletions(-) diff --git a/libbb/u_signal_names.c b/libbb/u_signal_names.c index b3038e32d..5ef5c3f28 100644 --- a/libbb/u_signal_names.c +++ b/libbb/u_signal_names.c @@ -12,6 +12,15 @@ //config: help //config: Support RTMIN[+n] and RTMAX[-n] signal names //config: in kill, killall etc. This costs ~250 bytes. +//config:config FEATURE_RTMINMAX_USE_LIBC_DEFINITIONS +//config: bool "Use the definitions of SIGRTMIN/SIGRTMAX provided by libc" +//config: depends on FEATURE_RTMINMAX +//config: help +//config: Some C libraries reserve a few real-time signals for internal +//config: use, and adjust the values of SIGRTMIN/SIGRTMAX seen by +//config: applications accordingly. Saying yes here means that a signal +//config: name RTMIN+n will be interpreted according to the libc definition +//config: of SIGRTMIN, and not the raw definition provided by the kernel. #include "libbb.h" @@ -123,7 +132,7 @@ static const char signals[][7] ALIGN1 = { #ifdef SIGSYS [SIGSYS ] = "SYS", #endif -#if ENABLE_FEATURE_RTMINMAX +#if ENABLE_FEATURE_RTMINMAX && !ENABLE_FEATURE_RTMINMAX_USE_LIBC_DEFINITIONS # ifdef __SIGRTMIN [__SIGRTMIN] = "RTMIN", # endif @@ -140,6 +149,7 @@ static const char signals[][7] ALIGN1 = { int FAST_FUNC get_signum(const char *name) { unsigned i; + unsigned sigrtmin, sigrtmax; i = bb_strtou(name, NULL, 10); if (!errno && i < NSIG) /* for shells, we allow 0 too */ @@ -168,10 +178,13 @@ int FAST_FUNC get_signum(const char *name) # endif #endif -#if ENABLE_FEATURE_RTMINMAX -# if defined(SIGRTMIN) && defined(SIGRTMAX) -/* libc may use some rt sigs for pthreads and therefore "remap" SIGRTMIN/MAX, - * but we want to use "raw" SIGRTMIN/MAX. Underscored names, if exist, provide +#if ENABLE_FEATURE_RTMINMAX && defined(SIGRTMIN) && defined(SIGRTMAX) +# if ENABLE_FEATURE_RTMINMAX_USE_LIBC_DEFINITIONS +/* Use the libc provided values. */ + sigrtmin = SIGRTMIN; + sigrtmax = SIGRTMAX; +# else +/* Use the "raw SIGRTMIN/MAX. Underscored names, if exist, provide * them. If they don't exist, fall back to non-underscored ones: */ # if !defined(__SIGRTMIN) # define __SIGRTMIN SIGRTMIN @@ -179,25 +192,27 @@ int FAST_FUNC get_signum(const char *name) # if !defined(__SIGRTMAX) # define __SIGRTMAX SIGRTMAX # endif + sigrtmin = __SIGRTMIN; + sigrtmax = __SIGRTMAX; +# endif if (strncasecmp(name, "RTMIN", 5) == 0) { if (!name[5]) - return __SIGRTMIN; + return sigrtmin; if (name[5] == '+') { i = bb_strtou(name + 6, NULL, 10); - if (!errno && i <= __SIGRTMAX - __SIGRTMIN) - return __SIGRTMIN + i; + if (!errno && i <= sigrtmax - sigrtmin) + return sigrtmin + i; } } else if (strncasecmp(name, "RTMAX", 5) == 0) { if (!name[5]) - return __SIGRTMAX; + return sigrtmax; if (name[5] == '-') { i = bb_strtou(name + 6, NULL, 10); - if (!errno && i <= __SIGRTMAX - __SIGRTMIN) - return __SIGRTMAX - i; + if (!errno && i <= sigrtmax - sigrtmin) + return sigrtmax - i; } } -# endif #endif return -1; @@ -228,8 +243,16 @@ void FAST_FUNC print_signames(void) printf("%2u) %s\n", signo, name); } #if ENABLE_FEATURE_RTMINMAX -# ifdef __SIGRTMAX +# if ENABLE_FEATURE_RTMINMAX_USE_LIBC_DEFINITIONS +# if defined(SIGRTMIN) && defined(SIGRTMAX) + printf("%2u) %s\n", SIGRTMIN, "RTMIN"); + printf("%2u) %s\n", SIGRTMAX, "RTMAX"); +# endif +# else +// __SIGRTMIN is included in signals[] array. +# ifdef __SIGRTMAX printf("%2u) %s\n", __SIGRTMAX, "RTMAX"); +# endif # endif #endif } -- 2.16.4 _______________________________________________ busybox mailing list [email protected] http://lists.busybox.net/mailman/listinfo/busybox
