Message ID | 6570a09c7a6652d387548c8af2dd39fc37df9174.1620323953.git.fweimer@redhat.com |
---|---|
State | New |
Headers | show |
Series | Linux: Move most stack management out of libpthread | expand |
On 5/6/21 2:10 PM, Florian Weimer via Libc-alpha wrote: > 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. LGTM. Tested on x86_64 and i686 without regression. Tested-by: Carlos O'Donell <carlos@redhat.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com> > --- > sysdeps/unix/sysdep.h | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/sysdeps/unix/sysdep.h b/sysdeps/unix/sysdep.h > index 2fa6bfa135..664d093c05 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 \ > { \ >
diff --git a/sysdeps/unix/sysdep.h b/sysdeps/unix/sysdep.h index 2fa6bfa135..664d093c05 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 \ { \