diff options
| author | Florian Weimer <fweimer@redhat.com> | 2021-05-10 10:31:41 +0200 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2021-05-10 10:31:41 +0200 |
| commit | 1c75f89613a0b2428c21c19598559a2d64221cde (patch) | |
| tree | 55eb68a014e7e9a4bde5f9e095f03fa4bbb019a6 /sysdeps | |
| parent | 321789f61aa93c14390535aa3cf01846633cd022 (diff) | |
| download | glibc-1c75f89613a0b2428c21c19598559a2d64221cde.tar.gz glibc-1c75f89613a0b2428c21c19598559a2d64221cde.tar.xz glibc-1c75f89613a0b2428c21c19598559a2d64221cde.zip | |
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 <carlos@redhat.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/unix/sysdep.h | 11 |
1 files 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 \ { \ |