cmsg.3: CONFORMING TO: note which CMSG_* APIs are in current and upcoming POSIX

[thirdparty/man-pages.git] / man8 / ld.so.8

diff --git a/man8/ld.so.8 b/man8/ld.so.8
index 7755361e8db6d25a530eaa2320d56d8ec1af3dc8..f34eca3d88300df952b03e5ca402be7ac3696c0e 100644 (file)
--- a/man8/ld.so.8
+++ b/man8/ld.so.8
@@ -2,7 +2,7 @@
 .\" This is in the public domain
 .\" %%%LICENSE_END
 .\"
-.TH LD.SO 8 2019-02-27 "GNU" "Linux Programmer's Manual"
+.TH LD.SO 8 2019-08-02 "GNU" "Linux Programmer's Manual"
 .SH NAME
 ld.so, ld\-linux.so \- dynamic linker/loader
 .SH SYNOPSIS
@@ -33,17 +33,17 @@ during compilation.
 .PP
 The program
 .B ld.so
-handles a.out binaries, a format used long ago;
+handles a.out binaries, a binary format used long ago.
+The program
 .B ld\-linux.so*
 (\fI/lib/ld\-linux.so.1\fP for libc5, \fI/lib/ld\-linux.so.2\fP for glibc2)
-handles ELF,
-which everybody has been using for years now.
-Otherwise, both have the same behavior, and use the same
-support files and programs as
-.BR ldd (1),
+handles binaries that are in the more modern ELF format.
+Both programs have the same behavior, and use the same
+support files and programs
+.RB ( ldd (1),
 .BR ldconfig (8),
 and
-.IR /etc/ld.so.conf .
+.IR /etc/ld.so.conf ).
 .PP
 When resolving shared object dependencies,
 the dynamic linker first inspects each dependency
@@ -111,7 +111,11 @@ Thus, an application located in
 .I somedir/app
 could be compiled with
 .IP
-    gcc \-Wl,\-rpath,\(aq$ORIGIN/../lib\(aq
+.in +4n
+.EX
+gcc \-Wl,\-rpath,\(aq$ORIGIN/../lib\(aq
+.EE
+.in
 .IP
 so that it finds an associated shared object in
 .I somedir/lib
@@ -218,10 +222,28 @@ Various environment variables influence the operation of the dynamic linker.
 .\"
 .SS Secure-execution mode
 For security reasons,
-the effects of some environment variables are voided or modified if
-the dynamic linker determines that the binary should be
-run in secure-execution mode.
-(For details, see the discussion of individual environment variables below.)
+if the dynamic linker determines that a binary should be
+run in secure-execution mode,
+the effects of some environment variables are voided or modified,
+and furthermore those environment variables are stripped from the environment,
+so that the program does not even see the definitions.
+Some of these environment variables affect the operation of
+the dynamic linker itself, and are described below.
+Other environment variables treated in this way include:
+.BR GCONV_PATH ,
+.BR GETCONF_DIR ,
+.BR HOSTALIASES ,
+.BR LOCALDOMAIN ,
+.BR LOCPATH ,
+.BR MALLOC_TRACE ,
+.BR NIS_PATH ,
+.BR NLSPATH ,
+.BR RESOLV_HOST_CONF ,
+.BR RES_OPTIONS ,
+.BR TMPDIR ,
+and
+.BR TZDIR .
+.PP
 A binary is executed in secure-execution mode if the
 .B AT_SECURE
 entry in the auxiliary vector (see
@@ -393,12 +415,13 @@ Then there are lots of more or less obscure variables,
 many obsolete or only for internal use.
 .TP
 .BR LD_AUDIT " (since glibc 2.4)"
-A colon-separated list of user-specified, ELF shared objects
+A list of user-specified, ELF shared objects
 to be loaded before all others in a separate linker namespace
 (i.e., one that does not intrude upon the normal symbol bindings that
 would occur in the process)
-and there is no support for escaping the separator.
 These objects can be used to audit the operation of the dynamic linker.
+The items in the list are colon-separated,
+and there is no support for escaping the separator.
 .IP
 .B LD_AUDIT
 is ignored in secure-execution mode.
@@ -409,7 +432,7 @@ loading a new shared object, resolving a symbol,
 or calling a symbol from another shared object\(emby
 calling an appropriate function within the audit shared object.
 For details, see
-.BR rtld-audit (7).
+.BR rtld\-audit (7).
 The auditing interface is largely compatible with that provided on Solaris,
 as described in its
 .IR "Linker and Libraries Guide" ,
@@ -681,7 +704,6 @@ randomization (ASLR),
 .B LD_PREFER_MAP_32BIT_EXEC
 is always disabled in secure-execution mode.
 .SH FILES
-.PD 0
 .TP
 .I /lib/ld.so
 a.out dynamic linker/loader
@@ -718,7 +740,6 @@ as a temporary workaround to a library misconfiguration issue.)
 .TP
 .I lib*.so*
 shared objects
-.PD
 .SH NOTES
 .SS Hardware capabilities
 Some shared objects are compiled using hardware-specific instructions which do
@@ -731,6 +752,8 @@ machine and selects the most suitable version of a given shared object.
 Hardware capability directories can be cascaded to combine CPU features.
 The list of supported hardware capability names depends on the CPU.
 The following names are currently recognized:
+.\" Presumably, this info comes from sysdeps/i386/dl-procinfo.c and
+.\" similar files
 .TP
 .B Alpha
 ev4, ev5, ev56, ev6, ev67
@@ -762,7 +785,7 @@ mtrr, pat, pbe, pge, pn, pse36, sep, ss, sse, sse2, tm
 .BR getauxval (3),
 .BR elf (5),
 .BR capabilities (7),
-.BR rtld-audit (7),
+.BR rtld\-audit (7),
 .BR ldconfig (8),
 .BR sln (8)
 .\" .SH AUTHORS