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authorSverker Eriksson <[email protected]>2016-02-18 16:24:34 +0100
committerSverker Eriksson <[email protected]>2016-02-18 16:24:34 +0100
commit2fc3f4c31ee71174ccf3478553a236a486e542c0 (patch)
treed828c71e2e2086cf078b80f1b849ee0f27d5e6ac /erts/emulator/hipe
parenteae8965a58b049cef1562b4462b05d9cab5286c3 (diff)
parent22ec76d8bc0e4dc0017791a7bd700b3d3565311a (diff)
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Merge branch 'sverk/erts-hipe_x86_signal-cleanups'
OTP-13341 * sverk/erts-hipe_x86_signal-cleanups: hipe_sigaltstack: correct initialization of ss.ss_flags hipe_x86_signal: cleanups hipe_x86_signal: cleanups hipe_x86_signal: cleanups hipe_x86_signal: cleanups hipe_x86_signal: cleanups hipe_x86_signal: cleanups
Diffstat (limited to 'erts/emulator/hipe')
-rw-r--r--erts/emulator/hipe/hipe_x86_signal.c201
1 files changed, 55 insertions, 146 deletions
diff --git a/erts/emulator/hipe/hipe_x86_signal.c b/erts/emulator/hipe/hipe_x86_signal.c
index b7dae88417..0ecd13c4bc 100644
--- a/erts/emulator/hipe/hipe_x86_signal.c
+++ b/erts/emulator/hipe/hipe_x86_signal.c
@@ -38,9 +38,6 @@
*
* Our solution is to override the C library's signal handler setup
* procedure with our own which enforces the SA_ONSTACK flag.
- *
- * XXX: This code only supports Linux with glibc-2.1 or above,
- * and Solaris 8.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
@@ -55,27 +52,6 @@
#include "hipe_signal.h"
#if __GLIBC__ == 2 && (__GLIBC_MINOR__ >= 3)
-/* See comment below for glibc 2.2. */
-#ifndef __USE_GNU
-#define __USE_GNU /* to un-hide RTLD_NEXT */
-#endif
-#include <dlfcn.h>
-static int (*__next_sigaction)(int, const struct sigaction*, struct sigaction*);
-#define init_done() (__next_sigaction != 0)
-extern int __sigaction(int, const struct sigaction*, struct sigaction*);
-#define __SIGACTION __sigaction
-static void do_init(void)
-{
- __next_sigaction = dlsym(RTLD_NEXT, "__sigaction");
- if (__next_sigaction != 0)
- return;
- perror("dlsym");
- abort();
-}
-#define INIT() do { if (!init_done()) do_init(); } while (0)
-#endif /* glibc 2.3 */
-
-#if __GLIBC__ == 2 && (__GLIBC_MINOR__ == 2 /*|| __GLIBC_MINOR__ == 3*/)
/*
* __libc_sigaction() is the core routine.
* Without libpthread, sigaction() and __sigaction() are both aliases
@@ -100,65 +76,14 @@ static void do_init(void)
* old BSD or SysV interfaces.
* glibc's internal calls to __sigaction() appear to be mostly safe.
* hipe_signal_init() fixes some unsafe ones, e.g. the SIGPROF handler.
- *
- * Tested with glibc-2.1.92 on RedHat 7.0, glibc-2.2.2 on RedHat 7.1,
- * glibc-2.2.4 on RedHat 7.2, and glibc-2.2.5 on RedHat 7.3.
*/
-#if 0
-/* works with 2.2.5 and 2.2.4, but not 2.2.2 or 2.1.92 */
+#ifndef __USE_GNU
#define __USE_GNU /* to un-hide RTLD_NEXT */
-#include <dlfcn.h>
-static int (*__next_sigaction)(int, const struct sigaction*, struct sigaction*);
-#define init_done() (__next_sigaction != 0)
-#define __SIGACTION __sigaction
-static void do_init(void)
-{
- __next_sigaction = dlsym(RTLD_NEXT, "__sigaction");
- if (__next_sigaction != 0)
- return;
- perror("dlsym");
- abort();
-}
-#define INIT() do { if (!init_done()) do_init(); } while (0)
-#else
-/* semi-works with all 2.2 versions so far */
-extern int __sigaction(int, const struct sigaction*, struct sigaction*);
-#define __next_sigaction __sigaction /* pthreads-aware version */
-#undef __SIGACTION /* we can't override __sigaction() */
-#define INIT() do{}while(0)
#endif
-#endif /* glibc 2.2 */
-
-#if __GLIBC__ == 2 && __GLIBC_MINOR__ == 1
-/*
- * __sigaction() is the core routine.
- * Without libpthread, sigaction() is an alias for __sigaction().
- * libpthread redefines sigaction() as a non-trivial wrapper around
- * __sigaction().
- * glibc has internal calls to both sigaction() and __sigaction().
- *
- * Overriding __sigaction() would be ideal, but doing so breaks
- * libpthread (threads hang). Instead we override sigaction() and
- * use dlsym RTLD_NEXT to find glibc's version of sigaction().
- * glibc's internal calls to __sigaction() appear to be mostly safe.
- * hipe_signal_init() fixes some unsafe ones, e.g. the SIGPROF handler.
- *
- * Tested with glibc-2.1.3 on RedHat 6.2.
- */
-#include <dlfcn.h>
-static int (*__next_sigaction)(int, const struct sigaction*, struct sigaction*);
-#define init_done() (__next_sigaction != 0)
-#undef __SIGACTION
-static void do_init(void)
-{
- __next_sigaction = dlsym(RTLD_NEXT, "sigaction");
- if (__next_sigaction != 0)
- return;
- perror("dlsym");
- abort();
-}
-#define INIT() do { if (!init_done()) do_init(); } while (0)
-#endif /* glibc 2.1 */
+#define NEXT_SIGACTION "__sigaction"
+#define LIBC_SIGACTION __sigaction
+#define OVERRIDE_SIGACTION
+#endif /* glibc >= 2.3 */
/* Is there no standard identifier for Darwin/MacOSX ? */
#if defined(__APPLE__) && defined(__MACH__) && !defined(__DARWIN__)
@@ -181,21 +106,10 @@ static void do_init(void)
* The other _sigaction, _sigaction_no_bind I don't understand the purpose
* of and don't modify.
*/
-#include <dlfcn.h>
-static int (*__next_sigaction)(int, const struct sigaction*, struct sigaction*);
-#define init_done() (__next_sigaction != 0)
-extern int _sigaction(int, const struct sigaction*, struct sigaction*);
-#define __SIGACTION _sigaction
-static void do_init(void)
-{
- __next_sigaction = dlsym(RTLD_NEXT, "sigaction");
- if (__next_sigaction != 0)
- return;
- perror("dlsym_darwin");
- abort();
-}
+#define NEXT_SIGACTION "sigaction"
+#define LIBC_SIGACTION _sigaction
+#undef OVERRIDE_SIGACTION
#define _NSIG NSIG
-#define INIT() do { if (!init_done()) do_init(); } while (0)
#endif /* __DARWIN__ */
#if defined(__sun__)
@@ -218,20 +132,10 @@ static void do_init(void)
* our init routine has had a chance to find _sigaction()'s address.
* This forces us to initialise at the first call.
*/
-#include <dlfcn.h>
-static int (*__next_sigaction)(int, const struct sigaction*, struct sigaction*);
-#define init_done() (__next_sigaction != 0)
-#define __SIGACTION _sigaction
-static void do_init(void)
-{
- __next_sigaction = dlsym(RTLD_NEXT, "_sigaction");
- if (__next_sigaction != 0)
- return;
- perror("dlsym");
- abort();
-}
+#define NEXT_SIGACTION "_sigaction"
+#define LIBC_SIGACTION _sigaction
+#define OVERRIDE_SIGACTION
#define _NSIG NSIG
-#define INIT() do { if (!init_done()) do_init(); } while (0)
#endif /* __sun__ */
#if defined(__FreeBSD__)
@@ -239,23 +143,22 @@ static void do_init(void)
* This is a copy of Darwin code for FreeBSD.
* CAVEAT: detailed semantics are not verified yet.
*/
-#include <dlfcn.h>
-static int (*__next_sigaction)(int, const struct sigaction*, struct sigaction*);
-#define init_done() (__next_sigaction != 0)
-extern int _sigaction(int, const struct sigaction*, struct sigaction*);
-#define __SIGACTION _sigaction
-static void do_init(void)
-{
- __next_sigaction = dlsym(RTLD_NEXT, "sigaction");
- if (__next_sigaction != 0)
- return;
- perror("dlsym_freebsd");
- abort();
-}
+#define NEXT_SIGACTION "sigaction"
+#define LIBC_SIGACTION _sigaction
+#undef OVERRIDE_SIGACTION
#define _NSIG NSIG
-#define INIT() do { if (!init_done()) do_init(); } while (0)
#endif /* __FreeBSD__ */
+#if defined(__NetBSD__)
+/*
+ * Note: This is only stub code to allow the build to succeed.
+ * Whether this actually provides the needed overrides for safe
+ * signal delivery or not is unknown.
+ */
+#undef NEXT_SIGACTION
+#undef OVERRIDE_SIGACTION
+#endif /* __NetBSD__ */
+
#if !(defined(__GLIBC__) || defined(__DARWIN__) || defined(__NetBSD__) || defined(__FreeBSD__) || defined(__sun__))
/*
* Unknown libc -- assume musl. Note: musl deliberately does not provide a musl-specific
@@ -265,30 +168,40 @@ static void do_init(void)
* There are libc-internal calls to __libc_sigaction which install handlers, so we must
* override __libc_sigaction rather than __sigaction.
*/
+#define NEXT_SIGACTION "__libc_sigaction"
+#define LIBC_SIGACTION __libc_sigaction
+#define OVERRIDE_SIGACTION
+#ifndef _NSIG
+#define _NSIG NSIG
+#endif
+#endif /* !(__GLIBC__ || __DARWIN__ || __NetBSD__ || __FreeBSD__ || __sun__) */
+
+#if defined(NEXT_SIGACTION)
+/*
+ * Initialize a function pointer to the libc core sigaction routine,
+ * to be used by our wrappers.
+ */
#include <dlfcn.h>
-static int (*__next_sigaction)(int, const struct sigaction*, struct sigaction*);
-#define init_done() (__next_sigaction != 0)
-#define __SIGACTION __libc_sigaction
+static int (*next_sigaction)(int, const struct sigaction*, struct sigaction*);
static void do_init(void)
{
- __next_sigaction = dlsym(RTLD_NEXT, "__libc_sigaction");
- if (__next_sigaction != 0)
+ next_sigaction = dlsym(RTLD_NEXT, NEXT_SIGACTION);
+ if (next_sigaction != 0)
return;
perror("dlsym");
abort();
}
-#ifndef _NSIG
-#define _NSIG NSIG
-#endif
-#define INIT() do { if (!init_done()) do_init(); } while (0)
-#endif /* !(__GLIBC__ || __DARWIN__ || __NetBSD__ || __FreeBSD__ || __sun__) */
+#define INIT() do { if (!next_sigaction) do_init(); } while (0)
+#else /* !defined(NEXT_SIGACTION) */
+#define INIT() do { } while (0)
+#endif /* !defined(NEXT_SIGACTION) */
-#if !defined(__NetBSD__)
+#if defined(NEXT_SIGACTION)
/*
* This is our wrapper for sigaction(). sigaction() can be called before
* hipe_signal_init() has been executed, especially when threads support
* has been linked with the executable. Therefore, we must initialise
- * __next_sigaction() dynamically, the first time it's needed.
+ * next_sigaction() dynamically, the first time it's needed.
*/
static int my_sigaction(int signum, const struct sigaction *act, struct sigaction *oldact)
{
@@ -304,24 +217,26 @@ static int my_sigaction(int signum, const struct sigaction *act, struct sigactio
newact.sa_flags |= SA_ONSTACK;
act = &newact;
}
- return __next_sigaction(signum, act, oldact);
+ return next_sigaction(signum, act, oldact);
}
#endif
+
+#if defined(LIBC_SIGACTION)
/*
* This overrides the C library's core sigaction() procedure, catching
* all its internal calls.
*/
-#ifdef __SIGACTION
-int __SIGACTION(int signum, const struct sigaction *act, struct sigaction *oldact)
+extern int LIBC_SIGACTION(int, const struct sigaction*, struct sigaction*);
+int LIBC_SIGACTION(int signum, const struct sigaction *act, struct sigaction *oldact)
{
return my_sigaction(signum, act, oldact);
}
#endif
+#if defined(OVERRIDE_SIGACTION)
/*
* This catches the application's own sigaction() calls.
*/
-#if !defined(__DARWIN__) && !defined(__NetBSD__) && !defined(__FreeBSD__)
int sigaction(int signum, const struct sigaction *act, struct sigaction *oldact)
{
return my_sigaction(signum, act, oldact);
@@ -336,15 +251,11 @@ static void hipe_sigaltstack(void *ss_sp)
stack_t ss;
ss.ss_sp = ss_sp;
- ss.ss_flags = SS_ONSTACK;
+ ss.ss_flags = 0;
ss.ss_size = SIGSTKSZ;
if (sigaltstack(&ss, NULL) < 0) {
- /* might be a broken pre-2.4 Linux kernel, try harder */
- ss.ss_flags = 0;
- if (sigaltstack(&ss, NULL) < 0) {
- perror("sigaltstack");
- abort();
- }
+ perror("sigaltstack");
+ abort();
}
}
@@ -381,9 +292,7 @@ void hipe_signal_init(void)
struct sigaction sa;
int i;
-#ifndef __NetBSD__
INIT();
-#endif
hipe_sigaltstack_init();