Arm: Fix LSB of GOT for Thumb2 only PLT.

[deliverable/binutils-gdb.git] / ld / ld.texi

diff --git a/ld/ld.texi b/ld/ld.texi
index eb7bcb993383fa57392acd45dda66956c9995f1f..9f562935bed06d67708e2cd72d276de5ec694f71 100644 (file)
--- a/ld/ld.texi
+++ b/ld/ld.texi
@@ -459,6 +459,48 @@ will contain a colon separated list of audit interfaces to use.  This
 option is only meaningful on ELF platforms supporting the rtld-audit interface.
 The -P option is provided for Solaris compatibility.
 
+@kindex --enable-non-contiguous-regions
+@item --enable-non-contiguous-regions
+This option avoids generating an error if an input section does not
+fit a matching output section. The linker tries to allocate the input
+section to subseque nt matching output sections, and generates an
+error only if no output section is large enough.  This is useful when
+several non-contiguous memory regions are available and the input
+section does not require a particular one.  The order in which input
+sections are evaluated does not change, for instance:
+
+@smallexample
+  MEMORY @{
+    MEM1 (rwx) : ORIGIN : 0x1000, LENGTH = 0x14
+    MEM2 (rwx) : ORIGIN : 0x1000, LENGTH = 0x40
+    MEM3 (rwx) : ORIGIN : 0x2000, LENGTH = 0x40
+  @}
+  SECTIONS @{
+    mem1 : @{ *(.data.*); @} > MEM1
+    mem2 : @{ *(.data.*); @} > MEM2
+    mem3 : @{ *(.data.*); @} > MEM2
+  @}
+
+  with input sections:
+  .data.1: size 8
+  .data.2: size 0x10
+  .data.3: size 4
+
+  results in .data.1 affected to mem1, and .data.2 and .data.3
+  affected to mem2, even though .data.3 would fit in mem3.
+@end smallexample
+
+This option is incompatible with INSERT statements because it changes
+the way input sections are mapped to output sections.
+
+@kindex --enable-non-contiguous-regions-warnings
+@item --enable-non-contiguous-regions-warnings
+This option enables warnings when
+@code{--enable-non-contiguous-regions} allows possibly unexpected
+matches in sections mapping, potentially leading to silently
+discarding a section instead of failing because it does not fit any
+output region.
+
 @cindex entry point, from command line
 @kindex -e @var{entry}
 @kindex --entry=@var{entry}
@@ -2011,6 +2053,7 @@ runtime linker would do.
 
 The linker uses the following search paths to locate required shared
 libraries:
+
 @enumerate
 @item
 Any directories specified by @option{-rpath-link} options.
@@ -2040,8 +2083,18 @@ libraries needed by it. The @code{DT_RPATH} entries are ignored if
 @item
 The default directories, normally @file{/lib} and @file{/usr/lib}.
 @item
-For a native linker on an ELF system, if the file @file{/etc/ld.so.conf}
-exists, the list of directories found in that file.
+For a linker for a Linux system, if the file @file{/etc/ld.so.conf}
+exists, the list of directories found in that file.  Note: the path
+to this file is prefixed with the @code{sysroot} value, if that is
+defined, and then any @code{prefix} string if the linker was
+configured with the @command{--prefix=<path>} option.
+@item
+For a native linker on a FreeBSD system, any directories specified by
+the @code{_PATH_ELF_HINTS} macro defined in the @file{elf-hints.h}
+header file.
+@item
+Any directories specifed by a @code{SEARCH_DIR} command in the
+linker script being used.
 @end enumerate
 
 If the required shared library is not found, the linker will issue a
@@ -7595,18 +7648,27 @@ disable the optimization.
 @cindex PowerPC64 __tls_get_addr optimization
 @kindex --tls-get-addr-optimize
 @kindex --no-tls-get-addr-optimize
+@kindex --tls-get-addr-regsave
+@kindex --no-tls-get-addr-regsave
 @item --tls-get-addr-optimize
 @itemx --no-tls-get-addr-optimize
-These options control whether PowerPC64 @command{ld} uses a special
+These options control how PowerPC64 @command{ld} uses a special
 stub to call __tls_get_addr.  PowerPC64 glibc 2.22 and later support
 an optimization that allows the second and subsequent calls to
 @code{__tls_get_addr} for a given symbol to be resolved by the special
-stub without calling in to glibc.  By default the linker enables this
-option when glibc advertises the availability of __tls_get_addr_opt.
-Forcing this option on when using an older glibc won't do much besides
-slow down your applications, but may be useful if linking an
-application against an older glibc with the expectation that it will
-normally be used on systems having a newer glibc.
+stub without calling in to glibc.  By default the linker enables
+generation of the stub when glibc advertises the availability of
+__tls_get_addr_opt.
+Using @option{--tls-get-addr-optimize} with an older glibc won't do
+much besides slow down your applications, but may be useful if linking
+an application against an older glibc with the expectation that it
+will normally be used on systems having a newer glibc.
+@option{--tls-get-addr-regsave} forces generation of a stub that saves
+and restores volatile registers around the call into glibc.  Normally,
+this is done when the linker detects a call to __tls_get_addr_desc.
+Such calls then go via the register saving stub to __tls_get_addr_opt.
+@option{--no-tls-get-addr-regsave} disables generation of the
+register saves.
 
 @cindex PowerPC64 OPD optimization
 @kindex --no-opd-optimize