mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-22 04:50:07 +00:00
f4c142bb9f
Instead of __dl_iterate_phdr. On ARM dlfo_eh_frame/dlfo_eh_count
maps to PT_ARM_EXIDX vaddr start / length.
On a Neoverse N1 machine with 160 cores, the following program:
$ cat test.c
#include <stdlib.h>
#include <pthread.h>
#include <assert.h>
enum {
niter = 1024,
ntimes = 128,
};
static void *
tf (void *arg)
{
int a = (int) arg;
for (int i = 0; i < niter; i++)
{
void *p[ntimes];
for (int j = 0; j < ntimes; j++)
p[j] = malloc (a * 128);
for (int j = 0; j < ntimes; j++)
free (p[j]);
}
return NULL;
}
int main (int argc, char *argv[])
{
enum { nthreads = 16 };
pthread_t t[nthreads];
for (int i = 0; i < nthreads; i ++)
assert (pthread_create (&t[i], NULL, tf, (void *) i) == 0);
for (int i = 0; i < nthreads; i++)
{
void *r;
assert (pthread_join (t[i], &r) == 0);
assert (r == NULL);
}
return 0;
}
$ arm-linux-gnueabihf-gcc -fsanitize=address test.c -o test
Improves from ~15s to 0.5s.
Checked on arm-linux-gnueabihf.
146 lines
6.0 KiB
C
146 lines
6.0 KiB
C
#ifndef _DLFCN_H
|
|
#include <dlfcn/dlfcn.h>
|
|
#ifndef _ISOMAC
|
|
#include <link.h> /* For ElfW. */
|
|
#include <stdbool.h>
|
|
|
|
extern __typeof (_dl_find_object) __dl_find_object;
|
|
hidden_proto (__dl_find_object)
|
|
|
|
/* Internally used flag. */
|
|
#define __RTLD_DLOPEN 0x80000000
|
|
#define __RTLD_SPROF 0x40000000
|
|
#define __RTLD_OPENEXEC 0x20000000
|
|
#define __RTLD_CALLMAP 0x10000000
|
|
#define __RTLD_AUDIT 0x08000000
|
|
#define __RTLD_SECURE 0x04000000 /* Apply additional security checks. */
|
|
#define __RTLD_NOIFUNC 0x02000000 /* Suppress calling ifunc functions. */
|
|
#define __RTLD_VDSO 0x01000000 /* Tell _dl_new_object the object is
|
|
system-loaded. */
|
|
|
|
#define __LM_ID_CALLER -2
|
|
|
|
/* These variables are defined and initialized in the startup code. */
|
|
extern int __libc_argc attribute_hidden;
|
|
extern char **__libc_argv attribute_hidden;
|
|
|
|
/* Now define the internal interfaces. */
|
|
|
|
/* Use RTLD_NOW here because:
|
|
1. In pthread_cancel_init we want to use RTLD_NOW to reduce the stack usage
|
|
of future cancellation operations, particularly when the target thread
|
|
is running with a small stack. Likewise for consistency we do the same
|
|
thing in __libgcc_s_init. RTLD_NOW will rarely make a difference for
|
|
__libgcc_s_init because unwinding is already in progress, so libgcc_s.so
|
|
has already been loaded if its unwinder is used (Bug 22636).
|
|
2. It allows us to provide robust fallback code at dlopen time for
|
|
incorrectly configured systems that mix old libnss_* modules
|
|
with newly installed libraries e.g. old libnss_dns.so.2 with new
|
|
libresolv.so.2. Using RTLD_LAZY here causes a failure at the
|
|
time the symbol is called and at that point it is much harder to
|
|
safely return an error (Bug 22766).
|
|
|
|
The use of RTLD_NOW also impacts gconv module loading, backtracing
|
|
(where the unwinder form libgcc_s.so is used), and IDNA functions
|
|
(which load libidn2), all of which load their respective DSOs on
|
|
demand, and so should not impact program startup. That is to say
|
|
that the DSOs are loaded as part of an API call and therefore we
|
|
will be calling that family of API functions shortly so RTLD_NOW or
|
|
RTLD_LAZY is not a big difference in performance, but RTLD_NOW has
|
|
better error handling semantics for the library. */
|
|
#define __libc_dlopen(name) \
|
|
__libc_dlopen_mode (name, RTLD_NOW | __RTLD_DLOPEN)
|
|
extern void *__libc_dlopen_mode (const char *__name, int __mode)
|
|
attribute_hidden;
|
|
extern void *__libc_dlsym (void *__map, const char *__name)
|
|
attribute_hidden;
|
|
extern void *__libc_dlvsym (void *map, const char *name, const char *version)
|
|
attribute_hidden;
|
|
extern int __libc_dlclose (void *__map)
|
|
attribute_hidden;
|
|
|
|
/* Locate shared object containing the given address. */
|
|
#ifdef ElfW
|
|
extern int _dl_addr (const void *address, Dl_info *info,
|
|
struct link_map **mapp, const ElfW(Sym) **symbolp)
|
|
attribute_hidden;
|
|
#endif
|
|
|
|
struct link_map;
|
|
|
|
/* Close an object previously opened by _dl_open. */
|
|
extern void _dl_close (void *map) attribute_hidden;
|
|
/* Same as above, but without locking and safety checks for user
|
|
provided map arguments. */
|
|
extern void _dl_close_worker (struct link_map *map, bool force)
|
|
attribute_hidden;
|
|
|
|
/* Look up NAME in shared object HANDLE (which may be RTLD_DEFAULT or
|
|
RTLD_NEXT). WHO is the calling function, for RTLD_NEXT. Returns
|
|
the symbol value, which may be NULL. */
|
|
extern void *_dl_sym (void *handle, const char *name, void *who)
|
|
attribute_hidden;
|
|
|
|
/* Look up version VERSION of symbol NAME in shared object HANDLE
|
|
(which may be RTLD_DEFAULT or RTLD_NEXT). WHO is the calling
|
|
function, for RTLD_NEXT. Returns the symbol value, which may be
|
|
NULL. */
|
|
extern void *_dl_vsym (void *handle, const char *name, const char *version,
|
|
void *who) attribute_hidden;
|
|
|
|
/* Helper function for <dlfcn.h> functions. Runs the OPERATE function via
|
|
_dl_catch_error. Returns zero for success, nonzero for failure; and
|
|
arranges for `dlerror' to return the error details.
|
|
ARGS is passed as argument to OPERATE. */
|
|
extern int _dlerror_run (void (*operate) (void *), void *args) attribute_hidden;
|
|
|
|
/* This structure is used to make the outer (statically linked)
|
|
implementation of dlopen and related functions to the inner libc
|
|
after static dlopen, via the GLRO (dl_dlfcn_hook) pointer. */
|
|
struct dlfcn_hook
|
|
{
|
|
/* Public interfaces. */
|
|
void *(*dlopen) (const char *file, int mode, void *dl_caller);
|
|
int (*dlclose) (void *handle);
|
|
void *(*dlsym) (void *handle, const char *name, void *dl_caller);
|
|
void *(*dlvsym) (void *handle, const char *name, const char *version,
|
|
void *dl_caller);
|
|
char *(*dlerror) (void);
|
|
int (*dladdr) (const void *address, Dl_info *info);
|
|
int (*dladdr1) (const void *address, Dl_info *info,
|
|
void **extra_info, int flags);
|
|
int (*dlinfo) (void *handle, int request, void *arg);
|
|
void *(*dlmopen) (Lmid_t nsid, const char *file, int mode, void *dl_caller);
|
|
|
|
/* Internal interfaces. */
|
|
void* (*libc_dlopen_mode) (const char *__name, int __mode);
|
|
void* (*libc_dlsym) (void *map, const char *name);
|
|
void* (*libc_dlvsym) (void *map, const char *name, const char *version);
|
|
int (*libc_dlclose) (void *map);
|
|
};
|
|
|
|
/* Note: These prototypes are for initializing _dlfcn_hook in static
|
|
builds; see __rtld_static_init. Internal calls in glibc should use
|
|
the __libc_dl* functions defined in elf/dl-libc.c instead. */
|
|
|
|
extern void *__dlopen (const char *file, int mode, void *caller);
|
|
extern void *__dlmopen (Lmid_t nsid, const char *file, int mode,
|
|
void *dl_caller);
|
|
extern int __dlclose (void *handle);
|
|
extern void *__dlsym (void *handle, const char *name, void *dl_caller);
|
|
extern void *__dlvsym (void *handle, const char *name, const char *version,
|
|
void *dl_caller);
|
|
extern int __dladdr (const void *address, Dl_info *info);
|
|
extern int __dladdr1 (const void *address, Dl_info *info,
|
|
void **extra_info, int flags);
|
|
extern int __dlinfo (void *handle, int request, void *arg);
|
|
extern char *__dlerror (void);
|
|
|
|
#ifndef SHARED
|
|
# undef DL_CALL_FCT
|
|
# define DL_CALL_FCT(fctp, args) ((fctp) args)
|
|
#endif
|
|
|
|
#endif
|
|
#endif
|