From 571b78a1d829263003a8560cca2c6d109bb19f0a Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Fri, 26 Jul 2013 00:08:25 +0200
Subject: m68k/atari: ARAnyM - Fix NatFeat module support
commit e8184e10f89736a23ea6eea8e24cd524c5c513d2 upstream.
As pointed out by Andreas Schwab, pointers passed to ARAnyM NatFeat calls
should be physical addresses, not virtual addresses.
Fortunately on Atari, physical and virtual kernel addresses are the same,
as long as normal kernel memory is concerned, so this usually worked fine
without conversion.
But for modules, pointers to literal strings are located in vmalloc()ed
memory. Depending on the version of ARAnyM, this causes the nf_get_id()
call to just fail, or worse, crash ARAnyM itself with e.g.
Gotcha! Illegal memory access. Atari PC = $968c
This is a big issue for distro kernels, who want to have all drivers as
loadable modules in an initrd.
Add a wrapper for nf_get_id() that copies the literal to the stack to
work around this issue.
Reported-by: Thorsten Glaser <tg@debian.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/m68k/emu/natfeat.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
diff --git a/arch/m68k/emu/natfeat.c b/arch/m68k/emu/natfeat.c
index 2291a7d69d4..fa277aecfb7 100644
--- a/arch/m68k/emu/natfeat.c
+++ b/arch/m68k/emu/natfeat.c
@@ -18,9 +18,11 @@
#include <asm/machdep.h>
#include <asm/natfeat.h>
+extern long nf_get_id2(const char *feature_name);
+
asm("\n"
-" .global nf_get_id,nf_call\n"
-"nf_get_id:\n"
+" .global nf_get_id2,nf_call\n"
+"nf_get_id2:\n"
" .short 0x7300\n"
" rts\n"
"nf_call:\n"
@@ -29,12 +31,25 @@ asm("\n"
"1: moveq.l #0,%d0\n"
" rts\n"
" .section __ex_table,\"a\"\n"
-" .long nf_get_id,1b\n"
+" .long nf_get_id2,1b\n"
" .long nf_call,1b\n"
" .previous");
-EXPORT_SYMBOL_GPL(nf_get_id);
EXPORT_SYMBOL_GPL(nf_call);
+long nf_get_id(const char *feature_name)
+{
+ /* feature_name may be in vmalloc()ed memory, so make a copy */
+ char name_copy[32];
+ size_t n;
+
+ n = strlcpy(name_copy, feature_name, sizeof(name_copy));
+ if (n >= sizeof(name_copy))
+ return 0;
+
+ return nf_get_id2(name_copy);
+}
+EXPORT_SYMBOL_GPL(nf_get_id);
+
void nfprint(const char *fmt, ...)
{
static char buf[256];
--
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