From: Florian Weimer <fweimer@redhat.com>
To: libc-alpha@sourceware.org
Subject: [PATCH 04/13] Linux: Explicitly disable cancellation checking in the dynamic loader
Date: Thu, 06 May 2021 20:10:14 +0200 [thread overview]
Message-ID: <6570a09c7a6652d387548c8af2dd39fc37df9174.1620323953.git.fweimer@redhat.com> (raw)
In-Reply-To: <cover.1620323953.git.fweimer@redhat.com>
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.
---
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 \
{ \
--
2.30.2
next prev parent reply other threads:[~2021-05-06 18:09 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-06 18:08 [PATCH 00/13] Linux: Move most stack management out of libpthread Florian Weimer
2021-05-06 18:08 ` [PATCH 01/13] scripts/versions.awk: Add strings and hashes to <first-versions.h> Florian Weimer
2021-05-09 21:42 ` Carlos O'Donell
2021-05-06 18:09 ` [PATCH v2 02/13] elf, nptl: Resolve recursive lock implementation early Florian Weimer
2021-05-09 21:42 ` Carlos O'Donell
2021-05-10 5:54 ` Florian Weimer
2021-05-06 18:10 ` [PATCH 03/13] nptl: Export __libc_multiple_threads from libc as an internal symbol Florian Weimer
2021-05-09 21:42 ` Carlos O'Donell
2021-05-06 18:10 ` Florian Weimer [this message]
2021-05-09 21:42 ` [PATCH 04/13] Linux: Explicitly disable cancellation checking in the dynamic loader Carlos O'Donell
2021-05-06 18:10 ` [PATCH 05/13] Linux: Simplify and fix the definition of SINGLE_THREAD_P Florian Weimer
2021-05-09 21:42 ` Carlos O'Donell
2021-05-06 18:10 ` [PATCH 06/13] nptl: Eliminate __pthread_multiple_threads Florian Weimer
2021-05-09 21:42 ` Carlos O'Donell
2021-05-06 18:10 ` [PATCH 07/13] elf: Introduce __tls_pre_init_tp Florian Weimer
2021-05-09 21:42 ` Carlos O'Donell
2021-05-06 18:10 ` [PATCH 08/13] nptl: Move more stack management variables into _rtld_global Florian Weimer
2021-05-09 21:42 ` Carlos O'Donell
2021-05-06 18:11 ` [PATCH 09/13] nptl: Simplify the change_stack_perm calling convention Florian Weimer
2021-05-09 21:42 ` Carlos O'Donell
2021-05-06 18:11 ` [PATCH 10/13] nptl: Move changing of stack permissions into ld.so Florian Weimer
2021-05-09 21:42 ` Carlos O'Donell
2021-05-06 18:11 ` [PATCH 11/13] nptl: Simplify resetting the in-flight stack in __reclaim_stacks Florian Weimer
2021-05-09 21:42 ` Carlos O'Donell
2021-05-06 18:11 ` [PATCH 12/13] nptl: Move __default_pthread_attr, __default_pthread_attr_lock into libc Florian Weimer
2021-05-09 21:41 ` Carlos O'Donell
2021-05-09 21:42 ` Carlos O'Donell
2021-05-06 18:11 ` [PATCH 13/13] Linux: Move __reclaim_stacks into the fork implementation in libc Florian Weimer
2021-05-09 21:41 ` Carlos O'Donell
2021-05-09 21:42 ` [PATCH 00/13] Linux: Move most stack management out of libpthread Carlos O'Donell
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