我有一个我成功构建的porgram，但是当我运行该程序时，我得到了一个段错误。
在这个程序的构建中，我建立了许多库的链接：
-llib1 -llib2 -llib3
segfault与源代码无关，但它与库加载lib2有关。
我尝试了一个hello world program
#include <stdio.h>
#include <stdlib.h>
int main()
{
printf("hello world! \n");
}
我使用-llib1 -llib2 -llib3
但是当我使用-llib1 -llib3
一般情况下（没有详细信息）可能导致此段错误的原因是什么？
修改
lib2在其一个头文件中包含以下行
# ifdef __GNUC__
__attribute__ ((__format__ (__printf__, 3, 4)))
# endif /* __GNUC__ */
以上代码是否会导致段错？
来自开源libminixml
minixml.h
extern int mxmlSetTextf(mxml_node_t *node, int whitespace,
const char *format, ...)
# ifdef __GNUC__
__attribute__ ((__format__ (__printf__, 3, 4)))
# endif /* __GNUC__ */
;
extern int mxmlSetUserData(mxml_node_t *node, void *data);
整个 minixml.h 文件：
#ifndef _mxml_h_
# define _mxml_h_
/*
* Include necessary headers...
*/
# include <stdio.h>
# include <stdlib.h>
# include <string.h>
# include <ctype.h>
# include <errno.h>
/*
* Constants...
*/
# define MXML_TAB 8 /* Tabs every N columns */
# define MXML_NO_CALLBACK 0 /* Don't use a type callback */
# define MXML_INTEGER_CALLBACK mxml_integer_cb
/* Treat all data as integers */
# define MXML_OPAQUE_CALLBACK mxml_opaque_cb
/* Treat all data as opaque */
# define MXML_REAL_CALLBACK mxml_real_cb
/* Treat all data as real numbers */
# define MXML_TEXT_CALLBACK 0 /* Treat all data as text */
# define MXML_IGNORE_CALLBACK mxml_ignore_cb
/* Ignore all non-element content */
# define MXML_NO_PARENT 0 /* No parent for the node */
# define MXML_DESCEND 1 /* Descend when finding/walking */
# define MXML_NO_DESCEND 0 /* Don't descend when finding/walking */
# define MXML_DESCEND_FIRST -1 /* Descend for first find */
# define MXML_WS_BEFORE_OPEN 0 /* Callback for before open tag */
# define MXML_WS_AFTER_OPEN 1 /* Callback for after open tag */
# define MXML_WS_BEFORE_CLOSE 2 /* Callback for before close tag */
# define MXML_WS_AFTER_CLOSE 3 /* Callback for after close tag */
# define MXML_ADD_BEFORE 0 /* Add node before specified node */
# define MXML_ADD_AFTER 1 /* Add node after specified node */
# define MXML_ADD_TO_PARENT NULL /* Add node relative to parent */
/*
* Data types...
*/
typedef enum mxml_sax_event_e /**** SAX event type. ****/
{
MXML_SAX_CDATA, /* CDATA node */
MXML_SAX_COMMENT, /* Comment node */
MXML_SAX_DATA, /* Data node */
MXML_SAX_DIRECTIVE, /* Processing directive node */
MXML_SAX_ELEMENT_CLOSE, /* Element closed */
MXML_SAX_ELEMENT_OPEN /* Element opened */
} mxml_sax_event_t;
typedef enum mxml_type_e /**** The XML node type. ****/
{
MXML_IGNORE = -1, /* Ignore/throw away node @since Mini-XML 2.3@ */
MXML_ELEMENT, /* XML element with attributes */
MXML_INTEGER, /* Integer value */
MXML_OPAQUE, /* Opaque string */
MXML_REAL, /* Real value */
MXML_TEXT, /* Text fragment */
MXML_CUSTOM /* Custom data @since Mini-XML 2.1@ */
} mxml_type_t;
typedef void (*mxml_custom_destroy_cb_t)(void *);
/**** Custom data destructor ****/
typedef void (*mxml_error_cb_t)(const char *);
/**** Error callback function ****/
typedef struct mxml_attr_s /**** An XML element attribute value. @private@ ****/
{
char *name; /* Attribute name */
char *value; /* Attribute value */
} mxml_attr_t;
typedef struct mxml_element_s /**** An XML element value. @private@ ****/
{
char *name; /* Name of element */
int num_attrs; /* Number of attributes */
mxml_attr_t *attrs; /* Attributes */
} mxml_element_t;
typedef struct mxml_text_s /**** An XML text value. @private@ ****/
{
int whitespace; /* Leading whitespace? */
char *string; /* Fragment string */
} mxml_text_t;
typedef struct mxml_custom_s /**** An XML custom value. @private@ ****/
{
void *data; /* Pointer to (allocated) custom data */
mxml_custom_destroy_cb_t destroy; /* Pointer to destructor function */
} mxml_custom_t;
typedef union mxml_value_u /**** An XML node value. @private@ ****/
{
mxml_element_t element; /* Element */
int integer; /* Integer number */
char *opaque; /* Opaque string */
double real; /* Real number */
mxml_text_t text; /* Text fragment */
mxml_custom_t custom; /* Custom data @since Mini-XML 2.1@ */
} mxml_value_t;
struct mxml_node_s /**** An XML node. @private@ ****/
{
mxml_type_t type; /* Node type */
struct mxml_node_s *next; /* Next node under same parent */
struct mxml_node_s *prev; /* Previous node under same parent */
struct mxml_node_s *parent; /* Parent node */
struct mxml_node_s *child; /* First child node */
struct mxml_node_s *last_child; /* Last child node */
mxml_value_t value; /* Node value */
int ref_count; /* Use count */
void *user_data; /* User data */
};
typedef struct mxml_node_s mxml_node_t; /**** An XML node. ****/
struct mxml_index_s /**** An XML node index. @private@ ****/
{
char *attr; /* Attribute used for indexing or NULL */
int num_nodes; /* Number of nodes in index */
int alloc_nodes; /* Allocated nodes in index */
int cur_node; /* Current node */
mxml_node_t **nodes; /* Node array */
};
typedef struct mxml_index_s mxml_index_t;
/**** An XML node index. ****/
typedef int (*mxml_custom_load_cb_t)(mxml_node_t *, const char *);
/**** Custom data load callback function ****/
typedef char *(*mxml_custom_save_cb_t)(mxml_node_t *);
/**** Custom data save callback function ****/
typedef int (*mxml_entity_cb_t)(const char *);
/**** Entity callback function */
typedef mxml_type_t (*mxml_load_cb_t)(mxml_node_t *);
/**** Load callback function ****/
typedef const char *(*mxml_save_cb_t)(mxml_node_t *, int);
/**** Save callback function ****/
typedef void (*mxml_sax_cb_t)(mxml_node_t *, mxml_sax_event_t, void *);
/**** SAX callback function ****/
/*
* C++ support...
*/
# ifdef __cplusplus
extern "C" {
# endif /* __cplusplus */
/*
* Prototypes...
*/
extern void mxmlAdd(mxml_node_t *parent, int where,
mxml_node_t *child, mxml_node_t *node);
extern void mxmlDelete(mxml_node_t *node);
extern void mxmlElementDeleteAttr(mxml_node_t *node,
const char *name);
extern const char *mxmlElementGetAttrValue(mxml_node_t *node, const char *name);
extern const char *mxmlElementGetAttrName(mxml_node_t *node, const char *value);
extern void mxmlElementSetAttr(mxml_node_t *node, const char *name,
const char *value);
extern void mxmlElementSetAttrf(mxml_node_t *node, const char *name,
const char *format, ...)
# ifdef __GNUC_ttt__
__attribute__ ((__format__ (__printf__, 3, 4)))
# endif /* __GNUC__ */
;
extern int mxmlEntityAddCallback(mxml_entity_cb_t cb);
extern const char *mxmlEntityGetName(int val);
extern int mxmlEntityGetValue(const char *name);
extern void mxmlEntityRemoveCallback(mxml_entity_cb_t cb);
extern mxml_node_t *mxmlFindElement(mxml_node_t *node, mxml_node_t *top,
const char *name, const char *attr,
const char *value, int descend);
extern mxml_node_t *mxmlFindElementText(mxml_node_t *node, mxml_node_t *top,
const char *text, int descend);
extern mxml_node_t *mxmlFindPath(mxml_node_t *node, const char *path);
extern const char *mxmlGetCDATA(mxml_node_t *node);
extern const void *mxmlGetCustom(mxml_node_t *node);
extern const char *mxmlGetElement(mxml_node_t *node);
extern mxml_node_t *mxmlGetFirstChild(mxml_node_t *node);
extern int mxmlGetInteger(mxml_node_t *node);
extern mxml_node_t *mxmlGetLastChild(mxml_node_t *node);
extern mxml_node_t *mxmlGetNextSibling(mxml_node_t *node);
extern const char *mxmlGetOpaque(mxml_node_t *node);
extern mxml_node_t *mxmlGetParent(mxml_node_t *node);
extern mxml_node_t *mxmlGetPrevSibling(mxml_node_t *node);
extern double mxmlGetReal(mxml_node_t *node);
extern int mxmlGetRefCount(mxml_node_t *node);
extern const char *mxmlGetText(mxml_node_t *node, int *whitespace);
extern mxml_type_t mxmlGetType(mxml_node_t *node);
extern void *mxmlGetUserData(mxml_node_t *node);
extern void mxmlIndexDelete(mxml_index_t *ind);
extern mxml_node_t *mxmlIndexEnum(mxml_index_t *ind);
extern mxml_node_t *mxmlIndexFind(mxml_index_t *ind,
const char *element,
const char *value);
extern int mxmlIndexGetCount(mxml_index_t *ind);
extern mxml_index_t *mxmlIndexNew(mxml_node_t *node, const char *element,
const char *attr);
extern mxml_node_t *mxmlIndexReset(mxml_index_t *ind);
extern mxml_node_t *mxmlLoadFd(mxml_node_t *top, int fd,
mxml_type_t (*cb)(mxml_node_t *));
extern mxml_node_t *mxmlLoadFile(mxml_node_t *top, FILE *fp,
mxml_type_t (*cb)(mxml_node_t *));
extern mxml_node_t *mxmlLoadString(mxml_node_t *top, const char *s,
mxml_type_t (*cb)(mxml_node_t *));
extern mxml_node_t *mxmlNewCDATA(mxml_node_t *parent, const char *string);
extern mxml_node_t *mxmlNewCustom(mxml_node_t *parent, void *data,
mxml_custom_destroy_cb_t destroy);
extern mxml_node_t *mxmlNewElement(mxml_node_t *parent, const char *name);
extern mxml_node_t *mxmlNewInteger(mxml_node_t *parent, int integer);
extern mxml_node_t *mxmlNewOpaque(mxml_node_t *parent, const char *opaque);
extern mxml_node_t *mxmlNewReal(mxml_node_t *parent, double real);
extern mxml_node_t *mxmlNewText(mxml_node_t *parent, int whitespace,
const char *string);
extern mxml_node_t *mxmlNewTextf(mxml_node_t *parent, int whitespace,
const char *format, ...)
# ifdef __GNUC_ttt__
__attribute__ ((__format__ (__printf__, 3, 4)))
# endif /* __GNUC__ */
;
extern mxml_node_t *mxmlNewXML(const char *version);
extern int mxmlRelease(mxml_node_t *node);
extern void mxmlRemove(mxml_node_t *node);
extern int mxmlRetain(mxml_node_t *node);
extern char *mxmlSaveAllocString(mxml_node_t *node,
mxml_save_cb_t cb);
extern int mxmlSaveFd(mxml_node_t *node, int fd,
mxml_save_cb_t cb);
extern int mxmlSaveFile(mxml_node_t *node, FILE *fp,
mxml_save_cb_t cb);
extern int mxmlSaveString(mxml_node_t *node, char *buffer,
int bufsize, mxml_save_cb_t cb);
extern mxml_node_t *mxmlSAXLoadFd(mxml_node_t *top, int fd,
mxml_type_t (*cb)(mxml_node_t *),
mxml_sax_cb_t sax, void *sax_data);
extern mxml_node_t *mxmlSAXLoadFile(mxml_node_t *top, FILE *fp,
mxml_type_t (*cb)(mxml_node_t *),
mxml_sax_cb_t sax, void *sax_data);
extern mxml_node_t *mxmlSAXLoadString(mxml_node_t *top, const char *s,
mxml_type_t (*cb)(mxml_node_t *),
mxml_sax_cb_t sax, void *sax_data);
extern int mxmlSetCDATA(mxml_node_t *node, const char *data);
extern int mxmlSetCustom(mxml_node_t *node, void *data,
mxml_custom_destroy_cb_t destroy);
extern void mxmlSetCustomHandlers(mxml_custom_load_cb_t load,
mxml_custom_save_cb_t save);
extern int mxmlSetElement(mxml_node_t *node, const char *name);
extern void mxmlSetErrorCallback(mxml_error_cb_t cb);
extern int mxmlSetInteger(mxml_node_t *node, int integer);
extern int mxmlSetOpaque(mxml_node_t *node, const char *opaque);
extern int mxmlSetReal(mxml_node_t *node, double real);
extern int mxmlSetText(mxml_node_t *node, int whitespace,
const char *string);
extern int mxmlSetTextf(mxml_node_t *node, int whitespace,
const char *format, ...)
# ifdef __GNUC_ttt__
__attribute__ ((__format__ (__printf__, 3, 4)))
# endif /* __GNUC__ */
;
extern int mxmlSetUserData(mxml_node_t *node, void *data);
extern void mxmlSetWrapMargin(int column);
extern mxml_node_t *mxmlWalkNext(mxml_node_t *node, mxml_node_t *top,
int descend);
extern mxml_node_t *mxmlWalkPrev(mxml_node_t *node, mxml_node_t *top,
int descend);
/*
* Semi-private functions...
*/
extern void mxml_error(const char *format, ...);
extern mxml_type_t mxml_ignore_cb(mxml_node_t *node);
extern mxml_type_t mxml_integer_cb(mxml_node_t *node);
extern mxml_type_t mxml_opaque_cb(mxml_node_t *node);
extern mxml_type_t mxml_real_cb(mxml_node_t *node);
/*
* C++ support...
*/
# ifdef __cplusplus
}
# endif /* __cplusplus */
#endif /* !_mxml_h_ */
在 minixml.h
中定义了3次strace的
strace ./test
execve("./test", ["./test"], [/* 10 vars */]) = 0
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|0x4000000, -1, 0) = 0x77885000
stat("/etc/ld.so.cache", 0x7fa6a5a0) = -1 ENOENT (No such file or directory)
open("/lib/libmicroxml.so.1", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/lib/libmicroxml.so.1", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/lib/libmicroxml.so.1", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0755, st_size=40128, ...}) = 0
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|0x4000000, -1, 0) = 0x77884000
read(3, "\177ELF\1\2\1\0\0\0\0\0\0\0\0\0\0\3\0\10\0\0\0\1\0\0\34@\0\0\0004"..., 4096) = 4096
old_mmap(NULL, 106496, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x77856000
old_mmap(0x77856000, 37332, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED, 3, 0) = 0x77856000
old_mmap(0x7786f000, 3264, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 3, 0x9000) = 0x7786f000
close(3) = 0
munmap(0x77884000, 4096) = 0
open("/lib/libgcc_s.so.1", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=78232, ...}) = 0
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|0x4000000, -1, 0) = 0x77884000
read(3, "\177ELF\1\2\1\0\0\0\0\0\0\0\0\0\0\3\0\10\0\0\0\1\0\0006\320\0\0\0004"..., 4096) = 4096
old_mmap(NULL, 147456, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x77832000
old_mmap(0x77832000, 76928, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED, 3, 0) = 0x77832000
old_mmap(0x77855000, 408, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 3, 0x13000) = 0x77855000
close(3) = 0
munmap(0x77884000, 4096) = 0
open("/lib/libc.so.0", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0755, st_size=413076, ...}) = 0
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|0x4000000, -1, 0) = 0x77884000
read(3, "\177ELF\1\2\1\0\0\0\0\0\0\0\0\0\0\3\0\10\0\0\0\1\0\0\253`\0\0\0004"..., 4096) = 4096
old_mmap(NULL, 503808, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x777b7000
old_mmap(0x777b7000, 405592, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED, 3, 0) = 0x777b7000
old_mmap(0x7782a000, 7572, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 3, 0x63000) = 0x7782a000
old_mmap(0x7782c000, 21036, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7782c000
close(3) = 0
munmap(0x77884000, 4096) = 0
open("/usr/lib/libgcc_s.so.1", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0755, st_size=169712, ...}) = 0
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|0x4000000, -1, 0) = 0x77884000
read(3, "\177ELF\1\2\1\0\0\0\0\0\0\0\0\0\0\3\0\10\0\0\0\1\0\0\307\220\0\0\0004"..., 4096) = 4096
old_mmap(NULL, 237568, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7777d000
old_mmap(0x7777d000, 169036, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED, 3, 0) = 0x7777d000
old_mmap(0x777b6000, 1776, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 3, 0x29000) = 0x777b6000
close(3) = 0
munmap(0x77884000, 4096) = 0
open("/usr/lib/libc.so.0", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0755, st_size=425968, ...}) = 0
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|0x4000000, -1, 0) = 0x77884000
read(3, "\177ELF\1\2\1\0\0\0\0\0\0\0\0\0\0\3\0\10\0\0\0\1\0\0\267`\0\0\0004"..., 4096) = 4096
old_mmap(NULL, 516096, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x776ff000
old_mmap(0x776ff000, 418924, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED, 3, 0) = 0x776ff000
old_mmap(0x77775000, 8176, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 3, 0x66000) = 0x77775000
old_mmap(0x77777000, 21784, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x77777000
close(3) = 0
munmap(0x77884000, 4096) = 0
open("/lib/libc.so.0", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0755, st_size=413076, ...}) = 0
close(3) = 0
stat("/lib/ld-uClibc.so.0", {st_mode=S_IFREG|0755, st_size=28976, ...}) = 0
open("/lib/libc.so.0", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0755, st_size=413076, ...}) = 0
close(3) = 0
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|0x4000000, -1, 0) = 0x77884000
set_thread_area(0x7788b440) = 0
mprotect(0x7782a000, 4096, PROT_READ) = 0
mprotect(0x77775000, 4096, PROT_READ) = 0
mprotect(0x77886000, 4096, PROT_READ) = 0
--- SIGSEGV (Segmentation fault) @ 0 (0) ---
+++ killed by SIGSEGV +++
Segmentation fault
答案 0 :(得分：1)
在共享库中，如果函数是使用__attribute__((constructor))定义的，则在加载共享库时它将自动执行。
由于您没有从该共享库调用任何函数，因此必须在该库的初始化代码（使用constuctor属性定义的代码）中发生崩溃。这很可能是库中的错误或者那些未满足的库的假设。很可能，它需要存在另一个共享库，这在您的系统中不存在。