From: Masahiro Yamada <masahiroy@xxxxxxxxxx>
commit 7ad4bd887d27c6b6ffbef216f19c19f8fe2b8f52 upstream.
You cannot include <generated/compile.h> here because it is generated
in init/Makefile but there is no guarantee that it happens before
arch/powerpc/mm/nohash/kaslr_booke.c is compiled for parallel builds.
The places where you can reliably include <generated/compile.h> are:
- init/ (because init/Makefile can specify the dependency)
- arch/*/boot/ (because it is compiled after vmlinux)
Commit f231e4333312 ("hexagon: get rid of #include <generated/compile.h>")
fixed the last breakage at that time, but powerpc re-added this.
<generated/compile.h> was unneeded because 'build_str' is almost the
same as 'linux_banner' defined in init/version.c
Let's copy the solution from MIPS.
(get_random_boot() in arch/mips/kernel/relocate.c)
Fixes: 6a38ea1d7b94 ("powerpc/fsl_booke/32: randomize the kernel image offset")
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Acked-by: Scott Wood <oss@xxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220604085050.4078927-1-masahiroy@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/mm/nohash/kaslr_booke.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
--- a/arch/powerpc/mm/nohash/kaslr_booke.c
+++ b/arch/powerpc/mm/nohash/kaslr_booke.c
@@ -18,7 +18,6 @@
#include <asm/prom.h>
#include <asm/kdump.h>
#include <mm/mmu_decl.h>
-#include <generated/compile.h>
#include <generated/utsrelease.h>
struct regions {
@@ -36,10 +35,6 @@ struct regions {
int reserved_mem_size_cells;
};
-/* Simplified build-specific string for starting entropy. */
-static const char build_str[] = UTS_RELEASE " (" LINUX_COMPILE_BY "@"
- LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION;
-
struct regions __initdata regions;
static __init void kaslr_get_cmdline(void *fdt)
@@ -72,7 +67,8 @@ static unsigned long __init get_boot_see
{
unsigned long hash = 0;
- hash = rotate_xor(hash, build_str, sizeof(build_str));
+ /* build-specific string for starting entropy. */
+ hash = rotate_xor(hash, linux_banner, strlen(linux_banner));
hash = rotate_xor(hash, fdt, fdt_totalsize(fdt));
return hash;
