[PATCH 1/2] m68k/atari: ARAnyM - Fix NatFeat module support

[PATCH 1/2] m68k/atari: ARAnyM - Fix NatFeat module support

[Geert Uytterhoeven]

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>
---
Queued for 3.11 and stable

 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 cb574ae..5a8da88 100644
--- a/arch/m68k/emu/natfeat.c
+++ b/arch/m68k/emu/natfeat.c
@@ -19,9 +19,11 @@
 #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"
@@ -30,12 +32,25 @@ 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];
-- 
1.7.9.5

[PATCH 2/2] m68k/atari: ARAnyM - Always use physical addresses in NatFeat calls

[Geert Uytterhoeven]

Pointers passed to ARAnyM NatFeat calls should be physical addresses,
not virtual addresses. This worked before because on Atari, physical and
virtual kernel addresses are the same, as long as normal kernel memory
is concerned.

Correct the few remaining places where virtual addresses were used.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
 arch/m68k/emu/natfeat.c |   14 +++++++-------
 arch/m68k/emu/nfblock.c |    4 ++--
 arch/m68k/emu/nfcon.c   |    8 +++++---
 arch/m68k/emu/nfeth.c   |    7 ++++---
 4 files changed, 18 insertions(+), 15 deletions(-)

diff --git a/arch/m68k/emu/natfeat.c b/arch/m68k/emu/natfeat.c
index 5a8da88..71b78ec 100644
--- a/arch/m68k/emu/natfeat.c
+++ b/arch/m68k/emu/natfeat.c
@@ -19,11 +19,11 @@
 #include <asm/machdep.h>
 #include <asm/natfeat.h>
 
-extern long nf_get_id2(const char *feature_name);
+extern long nf_get_id_phys(unsigned long feature_name);
 
 asm("\n"
-"	.global nf_get_id2,nf_call\n"
-"nf_get_id2:\n"
+"	.global nf_get_id_phys,nf_call\n"
+"nf_get_id_phys:\n"
 "	.short	0x7300\n"
 "	rts\n"
 "nf_call:\n"
@@ -32,7 +32,7 @@ asm("\n"
 "1:	moveq.l	#0,%d0\n"
 "	rts\n"
 "	.section __ex_table,\"a\"\n"
-"	.long	nf_get_id2,1b\n"
+"	.long	nf_get_id_phys,1b\n"
 "	.long	nf_call,1b\n"
 "	.previous");
 EXPORT_SYMBOL_GPL(nf_call);
@@ -47,7 +47,7 @@ long nf_get_id(const char *feature_name)
 	if (n >= sizeof(name_copy))
 		return 0;
 
-	return nf_get_id2(name_copy);
+	return nf_get_id_phys(virt_to_phys(name_copy));
 }
 EXPORT_SYMBOL_GPL(nf_get_id);
 
@@ -59,7 +59,7 @@ void nfprint(const char *fmt, ...)
 
 	va_start(ap, fmt);
 	n = vsnprintf(buf, 256, fmt, ap);
-	nf_call(nf_get_id("NF_STDERR"), buf);
+	nf_call(nf_get_id("NF_STDERR"), virt_to_phys(buf));
 	va_end(ap);
 }
 
@@ -84,7 +84,7 @@ void __init nf_init(void)
 	id = nf_get_id("NF_NAME");
 	if (!id)
 		return;
-	nf_call(id, buf, 256);
+	nf_call(id, virt_to_phys(buf), 256);
 	buf[255] = 0;
 
 	pr_info("NatFeats found (%s, %lu.%lu)\n", buf, version >> 16,
diff --git a/arch/m68k/emu/nfblock.c b/arch/m68k/emu/nfblock.c
index e301133..0721858 100644
--- a/arch/m68k/emu/nfblock.c
+++ b/arch/m68k/emu/nfblock.c
@@ -41,8 +41,8 @@ static inline s32 nfhd_read_write(u32 major, u32 minor, u32 rwflag, u32 recno,
 static inline s32 nfhd_get_capacity(u32 major, u32 minor, u32 *blocks,
 				    u32 *blocksize)
 {
-	return nf_call(nfhd_id + NFHD_GET_CAPACITY, major, minor, blocks,
-		       blocksize);
+	return nf_call(nfhd_id + NFHD_GET_CAPACITY, major, minor,
+		       virt_to_phys(blocks), virt_to_phys(blocksize));
 }
 
 static LIST_HEAD(nfhd_list);
diff --git a/arch/m68k/emu/nfcon.c b/arch/m68k/emu/nfcon.c
index 6685bf4..57e8c8f 100644
--- a/arch/m68k/emu/nfcon.c
+++ b/arch/m68k/emu/nfcon.c
@@ -15,6 +15,7 @@
 #include <linux/slab.h>
 #include <linux/err.h>
 #include <linux/uaccess.h>
+#include <linux/io.h>
 
 #include <asm/natfeat.h>
 
@@ -25,17 +26,18 @@ static struct tty_driver *nfcon_tty_driver;
 static void nfputs(const char *str, unsigned int count)
 {
 	char buf[68];
+	unsigned long phys = virt_to_phys(buf);
 
 	buf[64] = 0;
 	while (count > 64) {
 		memcpy(buf, str, 64);
-		nf_call(stderr_id, buf);
+		nf_call(stderr_id, phys);
 		str += 64;
 		count -= 64;
 	}
 	memcpy(buf, str, count);
 	buf[count] = 0;
-	nf_call(stderr_id, buf);
+	nf_call(stderr_id, phys);
 }
 
 static void nfcon_write(struct console *con, const char *str,
@@ -79,7 +81,7 @@ static int nfcon_tty_put_char(struct tty_struct *tty, unsigned char ch)
 {
 	char temp[2] = { ch, 0 };
 
-	nf_call(stderr_id, temp);
+	nf_call(stderr_id, virt_to_phys(temp));
 	return 1;
 }
 
diff --git a/arch/m68k/emu/nfeth.c b/arch/m68k/emu/nfeth.c
index 695cd73..a0985fd 100644
--- a/arch/m68k/emu/nfeth.c
+++ b/arch/m68k/emu/nfeth.c
@@ -195,7 +195,8 @@ static struct net_device * __init nfeth_probe(int unit)
 	char mac[ETH_ALEN], host_ip[32], local_ip[32];
 	int err;
 
-	if (!nf_call(nfEtherID + XIF_GET_MAC, unit, mac, ETH_ALEN))
+	if (!nf_call(nfEtherID + XIF_GET_MAC, unit, virt_to_phys(mac),
+		     ETH_ALEN))
 		return NULL;
 
 	dev = alloc_etherdev(sizeof(struct nfeth_private));
@@ -217,9 +218,9 @@ static struct net_device * __init nfeth_probe(int unit)
 	}
 
 	nf_call(nfEtherID + XIF_GET_IPHOST, unit,
-		host_ip, sizeof(host_ip));
+		virt_to_phys(host_ip), sizeof(host_ip));
 	nf_call(nfEtherID + XIF_GET_IPATARI, unit,
-		local_ip, sizeof(local_ip));
+		virt_to_phys(local_ip), sizeof(local_ip));
 
 	netdev_info(dev, KBUILD_MODNAME " addr:%s (%s) HWaddr:%pM\n", host_ip,
 		    local_ip, mac);
-- 
1.7.9.5