path: root/include
diff options
authorRich Felker <>2015-03-17 23:12:48 -0400
committerRich Felker <>2015-03-18 00:31:37 -0400
commitd5a5045382315e36588ca225889baa36ed0ed38f (patch)
treeb727e3ec85f49384a50f09568c62c0bb9410b6bd /include
parent76fd01177a32d602bc5ee7bd7ba65316adbae611 (diff)
fix MINSIGSTKSZ values for archs with large signal contexts
the previous values (2k min and 8k default) were too small for some archs. aarch64 reserves 4k in the signal context for future extensions and requires about 4.5k total, and powerpc reportedly uses over 2k. the new minimums are chosen to fit the saved context and also allow a minimal signal handler to run. since the default (SIGSTKSZ) has always been 6k larger than the minimum, it is also increased to maintain the 6k usable by the signal handler. this happens to be able to store one pathname buffer and should be sufficient for calling any function in libc that doesn't involve conversion between floating point and decimal representations. x86 (both 32-bit and 64-bit variants) may also need a larger minimum (around 2.5k) in the future to support avx-512, but the values on these archs are left alone for now pending further analysis. the value for PTHREAD_STACK_MIN is not increased to match MINSIGSTKSZ at this time. this is so as not to preclude applications from using extremely small thread stacks when they know they will not be handling signals. unfortunately cancellation and multi-threaded set*id() use signals as an implementation detail and therefore require a stack large enough for a signal context, so applications which use extremely small thread stacks may still need to avoid using these features.
Diffstat (limited to 'include')
1 files changed, 0 insertions, 2 deletions
diff --git a/include/signal.h b/include/signal.h
index b38241a3..559362f2 100644
--- a/include/signal.h
+++ b/include/signal.h
@@ -222,8 +222,6 @@ void (*sigset(int, void (*)(int)))(int);
#define POLL_HUP 6
#define SS_ONSTACK 1
#define SS_DISABLE 2
-#define MINSIGSTKSZ 2048
-#define SIGSTKSZ 8192
#if defined(_BSD_SOURCE) || defined(_GNU_SOURCE)