From 1c75f89613a0b2428c21c19598559a2d64221cde Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Mon, 10 May 2021 10:31:41 +0200 Subject: Linux: Explicitly disable cancellation checking in the dynamic loader Historically, SINGLE_THREAD_P is defined to 1 in the dynamic loader. This has the side effect of disabling cancellation points. In order to enable future use of SINGLE_THREAD_P for single-thread optimizations in the dynamic loader (which becomes important once more code is moved from libpthread), introduce a new NO_SYSCALL_CANCEL_CHECKING macro which is always 1 for IS_IN (rtld), indepdently of the actual SINGLE_THREAD_P value. Tested-by: Carlos O'Donell Reviewed-by: Carlos O'Donell --- sysdeps/unix/sysdep.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'sysdeps/unix') diff --git a/sysdeps/unix/sysdep.h b/sysdeps/unix/sysdep.h index 2fa6bfa..664d093 100644 --- a/sysdeps/unix/sysdep.h +++ b/sysdeps/unix/sysdep.h @@ -88,10 +88,17 @@ #define INLINE_SYSCALL_CALL(...) \ __INLINE_SYSCALL_DISP (__INLINE_SYSCALL, __VA_ARGS__) +#if IS_IN (rtld) +/* All cancellation points are compiled out in the dynamic loader. */ +# define NO_SYSCALL_CANCEL_CHECKING 1 +#else +# define NO_SYSCALL_CANCEL_CHECKING SINGLE_THREAD_P +#endif + #define SYSCALL_CANCEL(...) \ ({ \ long int sc_ret; \ - if (SINGLE_THREAD_P) \ + if (NO_SYSCALL_CANCEL_CHECKING) \ sc_ret = INLINE_SYSCALL_CALL (__VA_ARGS__); \ else \ { \ @@ -107,7 +114,7 @@ #define INTERNAL_SYSCALL_CANCEL(...) \ ({ \ long int sc_ret; \ - if (SINGLE_THREAD_P) \ + if (NO_SYSCALL_CANCEL_CHECKING) \ sc_ret = INTERNAL_SYSCALL_CALL (__VA_ARGS__); \ else \ { \ -- cgit v1.1