2019-08-09 09:53:21

by Jason Yan

[permalink] [raw]
Subject: [PATCH v6 09/12] powerpc/fsl_booke/kaslr: support nokaslr cmdline parameter

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

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

diff --git a/arch/powerpc/kernel/kaslr_booke.c b/arch/powerpc/kernel/kaslr_booke.c
index 9a360b6124ed..fd32ae10c218 100644
--- a/arch/powerpc/kernel/kaslr_booke.c
+++ b/arch/powerpc/kernel/kaslr_booke.c
@@ -334,6 +334,11 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size
return kaslr_offset;
}

+static inline __init bool kaslr_disabled(void)
+{
+ return strstr(boot_command_line, "nokaslr") != NULL;
+}
+
/*
* To see if we need to relocate the kernel to a random offset
* void *dt_ptr - address of the device tree
@@ -349,6 +354,8 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size)
kernel_sz = (unsigned long)_end - KERNELBASE;

kaslr_get_cmdline(dt_ptr);
+ if (kaslr_disabled())
+ return;

offset = kaslr_choose_location(dt_ptr, size, kernel_sz);

--
2.17.2