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-rw-r--r--include/linux/build-salt.h20
-rw-r--r--init/Kconfig9
-rw-r--r--init/version.c3
-rw-r--r--scripts/mod/modpost.c3
4 files changed, 35 insertions, 0 deletions
diff --git a/include/linux/build-salt.h b/include/linux/build-salt.h
new file mode 100644
index 000000000000..bb007bd05e7a
--- /dev/null
+++ b/include/linux/build-salt.h
@@ -0,0 +1,20 @@
+#ifndef __BUILD_SALT_H
+#define __BUILD_SALT_H
+
+#include <linux/elfnote.h>
+
+#define LINUX_ELFNOTE_BUILD_SALT 0x100
+
+#ifdef __ASSEMBLER__
+
+#define BUILD_SALT \
+ ELFNOTE(Linux, LINUX_ELFNOTE_BUILD_SALT, .asciz CONFIG_BUILD_SALT)
+
+#else
+
+#define BUILD_SALT \
+ ELFNOTE32("Linux", LINUX_ELFNOTE_BUILD_SALT, CONFIG_BUILD_SALT)
+
+#endif
+
+#endif /* __BUILD_SALT_H */
diff --git a/init/Kconfig b/init/Kconfig
index 041f3a022122..d39b31484c52 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -107,6 +107,15 @@ config LOCALVERSION_AUTO
which is done within the script "scripts/setlocalversion".)
+config BUILD_SALT
+ string "Build ID Salt"
+ default ""
+ help
+ The build ID is used to link binaries and their debug info. Setting
+ this option will use the value in the calculation of the build id.
+ This is mostly useful for distributions which want to ensure the
+ build is unique between builds. It's safe to leave the default.
+
config HAVE_KERNEL_GZIP
bool
diff --git a/init/version.c b/init/version.c
index bfb4e3f4955e..ef4012ec4375 100644
--- a/init/version.c
+++ b/init/version.c
@@ -7,6 +7,7 @@
*/
#include <generated/compile.h>
+#include <linux/build-salt.h>
#include <linux/export.h>
#include <linux/uts.h>
#include <linux/utsname.h>
@@ -49,3 +50,5 @@ const char linux_proc_banner[] =
"%s version %s"
" (" LINUX_COMPILE_BY "@" LINUX_COMPILE_HOST ")"
" (" LINUX_COMPILER ") %s\n";
+
+BUILD_SALT;
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 1663fb19343a..dc6d714e4dcb 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -2125,10 +2125,13 @@ static int check_modname_len(struct module *mod)
**/
static void add_header(struct buffer *b, struct module *mod)
{
+ buf_printf(b, "#include <linux/build-salt.h>\n");
buf_printf(b, "#include <linux/module.h>\n");
buf_printf(b, "#include <linux/vermagic.h>\n");
buf_printf(b, "#include <linux/compiler.h>\n");
buf_printf(b, "\n");
+ buf_printf(b, "BUILD_SALT;\n");
+ buf_printf(b, "\n");
buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
buf_printf(b, "\n");