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Diffstat (limited to 'man3/dlinfo.3')
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diff --git a/man3/dlinfo.3 b/man3/dlinfo.3 deleted file mode 100644 index 8fd42fc..0000000 --- a/man3/dlinfo.3 +++ /dev/null @@ -1,317 +0,0 @@ -'\" t -.\" Copyright (C) 2015 Michael Kerrisk <mtk.manpages@gmail.com> -.\" -.\" SPDX-License-Identifier: Linux-man-pages-copyleft -.\" -.TH dlinfo 3 2023-10-31 "Linux man-pages 6.7" -.SH NAME -dlinfo \- obtain information about a dynamically loaded object -.SH LIBRARY -Dynamic linking library -.RI ( libdl ", " \-ldl ) -.SH SYNOPSIS -.nf -.B #define _GNU_SOURCE -.B #include <link.h> -.B #include <dlfcn.h> -.P -.BR "int dlinfo(void *restrict " handle ", int " request \ -", void *restrict " info ); -.fi -.SH DESCRIPTION -The -.BR dlinfo () -function obtains information about the dynamically loaded object -referred to by -.I handle -(typically obtained by an earlier call to -.BR dlopen (3) -or -.BR dlmopen (3)). -The -.I request -argument specifies which information is to be returned. -The -.I info -argument is a pointer to a buffer used to store information -returned by the call; the type of this argument depends on -.IR request . -.P -The following values are supported for -.I request -(with the corresponding type for -.I info -shown in parentheses): -.TP -.BR RTLD_DI_LMID " (\fILmid_t *\fP)" -Obtain the ID of the link-map list (namespace) in which -.I handle -is loaded. -.TP -.BR RTLD_DI_LINKMAP " (\fIstruct link_map **\fP)" -Obtain a pointer to the -.I link_map -structure corresponding to -.IR handle . -The -.I info -argument points to a pointer to a -.I link_map -structure, defined in -.I <link.h> -as: -.IP -.in +4n -.EX -struct link_map { - ElfW(Addr) l_addr; /* Difference between the - address in the ELF file and - the address in memory */ - char *l_name; /* Absolute pathname where - object was found */ - ElfW(Dyn) *l_ld; /* Dynamic section of the - shared object */ - struct link_map *l_next, *l_prev; - /* Chain of loaded objects */ -\& - /* Plus additional fields private to the - implementation */ -}; -.EE -.in -.TP -.BR RTLD_DI_ORIGIN " (\fIchar *\fP)" -Copy the pathname of the origin of the shared object corresponding to -.I handle -to the location pointed to by -.IR info . -.TP -.BR RTLD_DI_SERINFO " (\fIDl_serinfo *\fP)" -Obtain the library search paths for the shared object referred to by -.IR handle . -The -.I info -argument is a pointer to a -.I Dl_serinfo -that contains the search paths. -Because the number of search paths may vary, -the size of the structure pointed to by -.I info -can vary. -The -.B RTLD_DI_SERINFOSIZE -request described below allows applications to size the buffer suitably. -The caller must perform the following steps: -.RS -.IP (1) 5 -Use a -.B RTLD_DI_SERINFOSIZE -request to populate a -.I Dl_serinfo -structure with the size -.RI ( dls_size ) -of the structure needed for the subsequent -.B RTLD_DI_SERINFO -request. -.IP (2) -Allocate a -.I Dl_serinfo -buffer of the correct size -.RI ( dls_size ). -.IP (3) -Use a further -.B RTLD_DI_SERINFOSIZE -request to populate the -.I dls_size -and -.I dls_cnt -fields of the buffer allocated in the previous step. -.IP (4) -Use a -.B RTLD_DI_SERINFO -to obtain the library search paths. -.RE -.IP -The -.I Dl_serinfo -structure is defined as follows: -.IP -.in +4n -.EX -typedef struct { - size_t dls_size; /* Size in bytes of - the whole buffer */ - unsigned int dls_cnt; /* Number of elements - in \[aq]dls_serpath\[aq] */ - Dl_serpath dls_serpath[1]; /* Actually longer, - \[aq]dls_cnt\[aq] elements */ -} Dl_serinfo; -.EE -.in -.IP -Each of the -.I dls_serpath -elements in the above structure is a structure of the following form: -.IP -.in +4n -.EX -typedef struct { - char *dls_name; /* Name of library search - path directory */ - unsigned int dls_flags; /* Indicates where this - directory came from */ -} Dl_serpath; -.EE -.in -.IP -The -.I dls_flags -field is currently unused, and always contains zero. -.TP -.BR RTLD_DI_SERINFOSIZE " (\fIDl_serinfo *\fP)" -Populate the -.I dls_size -and -.I dls_cnt -fields of the -.I Dl_serinfo -structure pointed to by -.I info -with values suitable for allocating a buffer for use in a subsequent -.B RTLD_DI_SERINFO -request. -.TP -.BR RTLD_DI_TLS_MODID " (\fIsize_t *\fP, since glibc 2.4)" -Obtain the module ID of this shared object's TLS (thread-local storage) -segment, as used in TLS relocations. -If this object does not define a TLS segment, zero is placed in -.IR *info . -.TP -.BR RTLD_DI_TLS_DATA " (\fIvoid **\fP, since glibc 2.4)" -Obtain a pointer to the calling -thread's TLS block corresponding to this shared object's TLS segment. -If this object does not define a PT_TLS segment, -or if the calling thread has not allocated a block for it, -NULL is placed in -.IR *info . -.SH RETURN VALUE -On success, -.BR dlinfo () -returns 0. -On failure, it returns \-1; the cause of the error can be diagnosed using -.BR dlerror (3). -.SH ATTRIBUTES -For an explanation of the terms used in this section, see -.BR attributes (7). -.TS -allbox; -lbx lb lb -l l l. -Interface Attribute Value -T{ -.na -.nh -.BR dlinfo () -T} Thread safety MT-Safe -.TE -.SH VERSIONS -The sets of requests supported by the various implementations -overlaps only partially. -.SH STANDARDS -GNU. -.SH HISTORY -glibc 2.3.3. -Solaris. -.SH EXAMPLES -The program below opens a shared objects using -.BR dlopen (3) -and then uses the -.B RTLD_DI_SERINFOSIZE -and -.B RTLD_DI_SERINFO -requests to obtain the library search path list for the library. -Here is an example of what we might see when running the program: -.P -.in +4n -.EX -$ \fB./a.out /lib64/libm.so.6\fP -dls_serpath[0].dls_name = /lib64 -dls_serpath[1].dls_name = /usr/lib64 -.EE -.in -.SS Program source -\& -.\" SRC BEGIN (dlinfo.c) -.EX -#define _GNU_SOURCE -#include <dlfcn.h> -#include <link.h> -#include <stdio.h> -#include <stdlib.h> -\& -int -main(int argc, char *argv[]) -{ - void *handle; - Dl_serinfo serinfo; - Dl_serinfo *sip; -\& - if (argc != 2) { - fprintf(stderr, "Usage: %s <libpath>\en", argv[0]); - exit(EXIT_FAILURE); - } -\& - /* Obtain a handle for shared object specified on command line. */ -\& - handle = dlopen(argv[1], RTLD_NOW); - if (handle == NULL) { - fprintf(stderr, "dlopen() failed: %s\en", dlerror()); - exit(EXIT_FAILURE); - } -\& - /* Discover the size of the buffer that we must pass to - RTLD_DI_SERINFO. */ -\& - if (dlinfo(handle, RTLD_DI_SERINFOSIZE, &serinfo) == \-1) { - fprintf(stderr, "RTLD_DI_SERINFOSIZE failed: %s\en", dlerror()); - exit(EXIT_FAILURE); - } -\& - /* Allocate the buffer for use with RTLD_DI_SERINFO. */ -\& - sip = malloc(serinfo.dls_size); - if (sip == NULL) { - perror("malloc"); - exit(EXIT_FAILURE); - } -\& - /* Initialize the \[aq]dls_size\[aq] and \[aq]dls_cnt\[aq] fields in the newly - allocated buffer. */ -\& - if (dlinfo(handle, RTLD_DI_SERINFOSIZE, sip) == \-1) { - fprintf(stderr, "RTLD_DI_SERINFOSIZE failed: %s\en", dlerror()); - exit(EXIT_FAILURE); - } -\& - /* Fetch and print library search list. */ -\& - if (dlinfo(handle, RTLD_DI_SERINFO, sip) == \-1) { - fprintf(stderr, "RTLD_DI_SERINFO failed: %s\en", dlerror()); - exit(EXIT_FAILURE); - } -\& - for (size_t j = 0; j < serinfo.dls_cnt; j++) - printf("dls_serpath[%zu].dls_name = %s\en", - j, sip\->dls_serpath[j].dls_name); -\& - exit(EXIT_SUCCESS); -} -.EE -.\" SRC END -.SH SEE ALSO -.BR dl_iterate_phdr (3), -.BR dladdr (3), -.BR dlerror (3), -.BR dlopen (3), -.BR dlsym (3), -.BR ld.so (8) |