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authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>2019-04-29 11:27:55 -0400
committerShuah Khan <skhan@linuxfoundation.org>2019-05-07 15:31:46 -0600
commit5b0c308a0565a94d2e1070cbf287197b676faaaf (patch)
treeea40e240db1dd0b3f0d3761ceffbe9a47dd76769 /tools/testing/selftests/rseq/rseq.h
parentrseq/selftests: Introduce __rseq_cs_ptr_array, rename __rseq_table to __rseq_cs (diff)
downloadlinux-dev-5b0c308a0565a94d2e1070cbf287197b676faaaf.tar.xz
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rseq/selftests: Use __rseq_handled symbol to coexist with glibc
In order to integrate rseq into user-space applications, expose a __rseq_handled symbol so many rseq users can be linked into the same application (e.g. librseq and glibc). The __rseq_refcount TLS variable is static to the librseq library. It ensures that rseq syscall registration/unregistration happens only for the most early/late caller to rseq_{,un}register_current_thread for each thread, thus ensuring that rseq is registered across the lifetime of all rseq users for a given thread. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> CC: Shuah Khan <shuah@kernel.org> CC: Carlos O'Donell <carlos@redhat.com> CC: Florian Weimer <fweimer@redhat.com> CC: Joseph Myers <joseph@codesourcery.com> CC: Szabolcs Nagy <szabolcs.nagy@arm.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: Ben Maurer <bmaurer@fb.com> CC: Peter Zijlstra <peterz@infradead.org> CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> CC: Boqun Feng <boqun.feng@gmail.com> CC: Will Deacon <will.deacon@arm.com> CC: Dave Watson <davejwatson@fb.com> CC: Paul Turner <pjt@google.com> CC: linux-api@vger.kernel.org Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Diffstat (limited to 'tools/testing/selftests/rseq/rseq.h')
-rw-r--r--tools/testing/selftests/rseq/rseq.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
index 6c1126e7f685..d40d60e7499e 100644
--- a/tools/testing/selftests/rseq/rseq.h
+++ b/tools/testing/selftests/rseq/rseq.h
@@ -44,6 +44,7 @@
#endif
extern __thread volatile struct rseq __rseq_abi;
+extern int __rseq_handled;
#define rseq_likely(x) __builtin_expect(!!(x), 1)
#define rseq_unlikely(x) __builtin_expect(!!(x), 0)