On 2019/8/6 15:59, Christophe Leroy wrote:
Le 05/08/2019 à 08:43, Jason Yan a écrit :
One may want to disable kaslr when boot, so provide a cmdline parameter
'nokaslr' to support this.
Signed-off-by: Jason Yan <yanaijie@xxxxxxxxxx>
Cc: Diana Craciun <diana.craciun@xxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Diana Craciun <diana.craciun@xxxxxxx>
Tested-by: Diana Craciun <diana.craciun@xxxxxxx>
Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxx>
Tiny comment below.
---
arch/powerpc/kernel/kaslr_booke.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/arch/powerpc/kernel/kaslr_booke.c
b/arch/powerpc/kernel/kaslr_booke.c
index 4b3f19a663fc..7c3cb41e7122 100644
--- a/arch/powerpc/kernel/kaslr_booke.c
+++ b/arch/powerpc/kernel/kaslr_booke.c
@@ -361,6 +361,18 @@ static unsigned long __init
kaslr_choose_location(void *dt_ptr, phys_addr_t size
return kaslr_offset;
}
+static inline __init bool kaslr_disabled(void)
+{
+ char *str;
+
+ str = strstr(boot_command_line, "nokaslr");
+ if ((str == boot_command_line) ||
+ (str > boot_command_line && *(str - 1) == ' '))
+ return true;
I don't think additional () are needed for the left part 'str ==
boot_command_line'
Agree.
+
+ return false;
+}
+
/*
* To see if we need to relocate the kernel to a random offset
* void *dt_ptr - address of the device tree
@@ -376,6 +388,8 @@ 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);
.
