[PATCH v6 08/12] powerpc/fsl_booke/kaslr: clear the original kernel if randomized
From: Jason Yan <yanaijie@huawei.com>
Date: 2019-08-09 09:52:20
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
The original kernel still exists in the memory, clear it now. 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> Reviewed-by: Christophe Leroy <redacted> Reviewed-by: Diana Craciun <redacted> Tested-by: Diana Craciun <redacted> --- 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 51a0b3749724..9a360b6124ed 100644
--- a/arch/powerpc/kernel/kaslr_booke.c
+++ b/arch/powerpc/kernel/kaslr_booke.c@@ -373,3 +373,14 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) reloc_kernel_entry(dt_ptr, kernstart_virt_addr); } + +void __init kaslr_late_init(void) +{ + /* If randomized, clear the original kernel */ + if (kernstart_virt_addr != KERNELBASE) { + unsigned long kernel_sz; + + kernel_sz = (unsigned long)_end - kernstart_virt_addr; + memzero_explicit((void *)KERNELBASE, kernel_sz); + } +}
diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index 213997d69729..64b2ac8a5343 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h@@ -151,8 +151,10 @@ extern void loadcam_multi(int first_idx, int num, int tmp_idx); #ifdef CONFIG_RANDOMIZE_BASE void kaslr_early_init(void *dt_ptr, phys_addr_t size); +void kaslr_late_init(void); #else static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {} +static inline void kaslr_late_init(void) {} #endif struct tlbcam {
diff --git a/arch/powerpc/mm/nohash/fsl_booke.c b/arch/powerpc/mm/nohash/fsl_booke.c
index 2dc27cf88add..b4eb06ceb189 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_late_init(); return; }
--
2.17.2