[PATCH v6 1/6] powerpc/mm: prepare kernel for KAsan on PPC32
From: Christophe Leroy <hidden>
Date: 2019-02-19 17:23:12
Also in:
linux-mm
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
In kernel/cputable.c, explicitly use memcpy() in order
to allow GCC to replace it with __memcpy() when KASAN is
selected.
Since commit 400c47d81ca38 ("powerpc32: memset: only use dcbz once cache is
enabled"), memset() can be used before activation of the cache,
so no need to use memset_io() for zeroing the BSS.
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Christophe Leroy <redacted>
---
arch/powerpc/kernel/cputable.c | 13 ++++++++++---
arch/powerpc/kernel/setup_32.c | 6 ++----
2 files changed, 12 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c
index 1eab54bc6ee9..cd12f362b61f 100644
--- a/arch/powerpc/kernel/cputable.c
+++ b/arch/powerpc/kernel/cputable.c@@ -2147,7 +2147,11 @@ void __init set_cur_cpu_spec(struct cpu_spec *s) struct cpu_spec *t = &the_cpu_spec; t = PTRRELOC(t); - *t = *s; + /* + * use memcpy() instead of *t = *s so that GCC replaces it + * by __memcpy() when KASAN is active + */ + memcpy(t, s, sizeof(*t)); *PTRRELOC(&cur_cpu_spec) = &the_cpu_spec; }
@@ -2161,8 +2165,11 @@ static struct cpu_spec * __init setup_cpu_spec(unsigned long offset, t = PTRRELOC(t); old = *t; - /* Copy everything, then do fixups */ - *t = *s; + /* + * Copy everything, then do fixups. Use memcpy() instead of *t = *s + * so that GCC replaces it by __memcpy() when KASAN is active + */ + memcpy(t, s, sizeof(*t)); /* * If we are overriding a previous value derived from the real
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 947f904688b0..5e761eb16a6d 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c@@ -73,10 +73,8 @@ notrace unsigned long __init early_init(unsigned long dt_ptr) { unsigned long offset = reloc_offset(); - /* First zero the BSS -- use memset_io, some platforms don't have - * caches on yet */ - memset_io((void __iomem *)PTRRELOC(&__bss_start), 0, - __bss_stop - __bss_start); + /* First zero the BSS */ + memset(PTRRELOC(&__bss_start), 0, __bss_stop - __bss_start); /* * Identify the CPU type and fix up code sections
--
2.13.3