x86/boot: Rename overlapping memcpy() to memmove()
Instead of having non-standard memcpy() behavior, explicitly call the new
function memmove(), make it available to the decompressors, and switch
the two overlap cases (screen scrolling and ELF parsing) to use memmove().
Additionally documents the purpose of compressed/string.c.
Suggested-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: H.J. Lu <hjl.tools@gmail.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20160426214606.GA5758@www.outflux.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index c57d785..6dde6cc 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -32,9 +32,11 @@
#undef memcpy
#undef memset
#define memzero(s, n) memset((s), 0, (n))
+#define memmove memmove
/* Functions used by the included decompressor code below. */
static void error(char *m);
+void *memmove(void *dest, const void *src, size_t n);
/*
* This is set up by the setup-routine at boot-time
@@ -80,7 +82,7 @@
{
int i;
- memcpy(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2);
+ memmove(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2);
for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2)
vidmem[i] = ' ';
}
@@ -307,7 +309,7 @@
#else
dest = (void *)(phdr->p_paddr);
#endif
- memcpy(dest, output + phdr->p_offset, phdr->p_filesz);
+ memmove(dest, output + phdr->p_offset, phdr->p_filesz);
break;
default: /* Ignore other PT_* */ break;
}