lkml.org 
[lkml]   [2019]   [Jul]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC PATCH 08/10] powerpc/fsl_booke/kaslr: clear the original kernel if randomized
Date
The original kernel still exists in the memory, clear it now.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: Diana Craciun <diana.craciun@nxp.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
---
arch/powerpc/kernel/kaslr_booke.c | 11 +++++++++++
arch/powerpc/mm/mmu_decl.h | 2 ++
arch/powerpc/mm/nohash/fsl_booke.c | 1 +
3 files changed, 14 insertions(+)

diff --git a/arch/powerpc/kernel/kaslr_booke.c b/arch/powerpc/kernel/kaslr_booke.c
index 90357f4bd313..00339c05879f 100644
--- a/arch/powerpc/kernel/kaslr_booke.c
+++ b/arch/powerpc/kernel/kaslr_booke.c
@@ -412,3 +412,14 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size)

reloc_kernel_entry(dt_ptr, kimage_vaddr);
}
+
+void __init kaslr_second_init(void)
+{
+ /* If randomized, clear the original kernel */
+ if (kimage_vaddr != KERNELBASE) {
+ unsigned long kernel_sz;
+
+ kernel_sz = (unsigned long)_end - kimage_vaddr;
+ memset((void *)KERNELBASE, 0, kernel_sz);
+ }
+}
diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index 754ae1e69f92..9912ee598f9b 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -150,8 +150,10 @@ extern void loadcam_multi(int first_idx, int num, int tmp_idx);

#ifdef CONFIG_RANDOMIZE_BASE
extern void kaslr_early_init(void *dt_ptr, phys_addr_t size);
+extern void kaslr_second_init(void);
#else
static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {}
+static inline void kaslr_second_init(void) {}
#endif

struct tlbcam {
diff --git a/arch/powerpc/mm/nohash/fsl_booke.c b/arch/powerpc/mm/nohash/fsl_booke.c
index 8d25a8dc965f..fa5a87f5c08e 100644
--- a/arch/powerpc/mm/nohash/fsl_booke.c
+++ b/arch/powerpc/mm/nohash/fsl_booke.c
@@ -269,6 +269,7 @@ notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
kernstart_addr = start;
if (is_second_reloc) {
virt_phys_offset = PAGE_OFFSET - memstart_addr;
+ kaslr_second_init();
return;
}

--
2.17.2
\
 
 \ /
  Last update: 2019-07-17 09:50    [W:0.247 / U:8.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site