[v7,09/12] powerpc/fsl_booke/kaslr: support nokaslr cmdline parameter

Commit Message

Jason Yan Sept. 20, 2019, 9:45 a.m. UTC

One may want to disable kaslr when boot, so provide a cmdline parameter
'nokaslr' to support this.

Signed-off-by: Jason Yan <[e-mail]>
Cc: Diana Craciun <[e-mail]>
Cc: Michael Ellerman <[e-mail]>
Cc: Christophe Leroy <[e-mail]>
Cc: Benjamin Herrenschmidt <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Nicholas Piggin <[e-mail]>
Cc: Kees Cook <[e-mail]>
Reviewed-by: Diana Craciun <[e-mail]>
Tested-by: Diana Craciun <[e-mail]>
Reviewed-by: Christophe Leroy <[e-mail]>
---
 arch/powerpc/mm/nohash/kaslr_booke.c | 7 +++++++
 1 file changed, 7 insertions(+)

Patch

diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c b/arch/powerpc/mm/nohash/kaslr_booke.c
index aa1b60c782e7..4a75f2d9bf0e 100644
--- a/arch/powerpc/mm/nohash/kaslr_booke.c
+++ b/arch/powerpc/mm/nohash/kaslr_booke.c
@@ -281,6 +281,11 @@  static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long index
 	return koffset;
 }
 
+static inline __init bool kaslr_disabled(void)
+{
+	return strstr(boot_command_line, "nokaslr") != NULL;
+}
+
 static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size,
 						  unsigned long kernel_sz)
 {
@@ -290,6 +295,8 @@  static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size
 	unsigned long index;
 
 	kaslr_get_cmdline(dt_ptr);
+	if (kaslr_disabled())
+		return 0;
 
 	random = get_boot_seed(dt_ptr);