Re: [RFC PATCH 09/10] powerpc/fsl_booke/kaslr: support nokaslr cmdline parameter
From: Christophe Leroy <hidden>
Date: 2019-07-29 11:39:02
Also in:
lkml
Le 17/07/2019 à 10:06, Jason Yan a écrit :
quoted hunk ↗ jump to hunk
One may want to disable kaslr when boot, so provide a cmdline parameter 'nokaslr' to support this. Signed-off-by: Jason Yan <yanaijie@huawei.com> Cc: Diana Craciun <redacted> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Christophe Leroy <redacted> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <redacted> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Kees Cook <redacted> --- 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 00339c05879f..e65a5d9d2ff1 100644 --- a/arch/powerpc/kernel/kaslr_booke.c +++ b/arch/powerpc/kernel/kaslr_booke.c@@ -373,6 +373,18 @@ 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(early_command_line, "nokaslr");
Why using early_command_line instead of boot_command_line ?
+ if ((str == early_command_line) || + (str > early_command_line && *(str - 1) == ' '))
Is that stuff really needed ? Why not just: return strstr(early_command_line, "nokaslr") != NULL;
+ return true; + + return false; +}
quoted hunk ↗ jump to hunk
+ /* * To see if we need to relocate the kernel to a random offset * void *dt_ptr - address of the device tree@@ -388,6 +400,8 @@ 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);
Christophe