MIPS: Fix exception handler memcpy()

MIPS: Fix exception handler memcpy()

[YunQiang Su]

From: Ben Hutchings <ben@decadent.org.uk>

The exception handler subroutines are declared as a single char, but
when copied to the required addresses the copy length is 0x80.

When range checks are enabled for memcpy() this results in a build
failure, with error messages such as:

In file included from arch/mips/mti-malta/malta-init.c:15:
In function 'memcpy',
    inlined from 'mips_nmi_setup' at arch/mips/mti-malta/malta-init.c:98:2:
include/linux/string.h:376:4: error: call to '__read_overflow2' declared with attribute error: detected read beyond size of object passed as 2nd parameter
  376 |    __read_overflow2();
      |    ^~~~~~~~~~~~~~~~~~

Change the declarations to use type char[].

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: YunQiang Su <syq@debian.org>
---
--- a/arch/mips/loongson2ef/common/init.c
+++ b/arch/mips/loongson2ef/common/init.c
@@ -19,10 +19,10 @@ unsigned long __maybe_unused _loongson_a
 static void __init mips_nmi_setup(void)
 {
 	void *base;
-	extern char except_vec_nmi;
+	extern char except_vec_nmi[];
 
 	base = (void *)(CAC_BASE + 0x380);
-	memcpy(base, &except_vec_nmi, 0x80);
+	memcpy(base, except_vec_nmi, 0x80);
 	flush_icache_range((unsigned long)base, (unsigned long)base + 0x80);
 }
 
--- a/arch/mips/loongson64/init.c
+++ b/arch/mips/loongson64/init.c
@@ -16,10 +16,10 @@
 static void __init mips_nmi_setup(void)
 {
 	void *base;
-	extern char except_vec_nmi;
+	extern char except_vec_nmi[];
 
 	base = (void *)(CAC_BASE + 0x380);
-	memcpy(base, &except_vec_nmi, 0x80);
+	memcpy(base, except_vec_nmi, 0x80);
 	flush_icache_range((unsigned long)base, (unsigned long)base + 0x80);
 }
 
--- a/arch/mips/mti-malta/malta-init.c
+++ b/arch/mips/mti-malta/malta-init.c
@@ -90,24 +90,24 @@ static void __init console_config(void)
 static void __init mips_nmi_setup(void)
 {
 	void *base;
-	extern char except_vec_nmi;
+	extern char except_vec_nmi[];
 
 	base = cpu_has_veic ?
 		(void *)(CAC_BASE + 0xa80) :
 		(void *)(CAC_BASE + 0x380);
-	memcpy(base, &except_vec_nmi, 0x80);
+	memcpy(base, except_vec_nmi, 0x80);
 	flush_icache_range((unsigned long)base, (unsigned long)base + 0x80);
 }
 
 static void __init mips_ejtag_setup(void)
 {
 	void *base;
-	extern char except_vec_ejtag_debug;
+	extern char except_vec_ejtag_debug[];
 
 	base = cpu_has_veic ?
 		(void *)(CAC_BASE + 0xa00) :
 		(void *)(CAC_BASE + 0x300);
-	memcpy(base, &except_vec_ejtag_debug, 0x80);
+	memcpy(base, except_vec_ejtag_debug, 0x80);
 	flush_icache_range((unsigned long)base, (unsigned long)base + 0x80);
 }
 
--- a/arch/mips/pistachio/init.c
+++ b/arch/mips/pistachio/init.c
@@ -83,12 +83,12 @@ phys_addr_t mips_cdmm_phys_base(void)
 static void __init mips_nmi_setup(void)
 {
 	void *base;
-	extern char except_vec_nmi;
+	extern char except_vec_nmi[];
 
 	base = cpu_has_veic ?
 		(void *)(CAC_BASE + 0xa80) :
 		(void *)(CAC_BASE + 0x380);
-	memcpy(base, &except_vec_nmi, 0x80);
+	memcpy(base, except_vec_nmi, 0x80);
 	flush_icache_range((unsigned long)base,
 			   (unsigned long)base + 0x80);
 }
@@ -96,12 +96,12 @@ static void __init mips_nmi_setup(void)
 static void __init mips_ejtag_setup(void)
 {
 	void *base;
-	extern char except_vec_ejtag_debug;
+	extern char except_vec_ejtag_debug[];
 
 	base = cpu_has_veic ?
 		(void *)(CAC_BASE + 0xa00) :
 		(void *)(CAC_BASE + 0x300);
-	memcpy(base, &except_vec_ejtag_debug, 0x80);
+	memcpy(base, except_vec_ejtag_debug, 0x80);
 	flush_icache_range((unsigned long)base,
 			   (unsigned long)base + 0x80);
 }

Re: MIPS: Fix exception handler memcpy()

[Thomas Bogendoerfer]

On Sat, May 23, 2020 at 11:50:34PM +0800, YunQiang Su wrote:
> From: Ben Hutchings <ben@decadent.org.uk>
> 
> The exception handler subroutines are declared as a single char, but
> when copied to the required addresses the copy length is 0x80.
> 
> When range checks are enabled for memcpy() this results in a build
> failure, with error messages such as:
> 
> In file included from arch/mips/mti-malta/malta-init.c:15:
> In function 'memcpy',
>     inlined from 'mips_nmi_setup' at arch/mips/mti-malta/malta-init.c:98:2:
> include/linux/string.h:376:4: error: call to '__read_overflow2' declared with attribute error: detected read beyond size of object passed as 2nd parameter
>   376 |    __read_overflow2();
>       |    ^~~~~~~~~~~~~~~~~~
> 
> Change the declarations to use type char[].
> 
> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
> Signed-off-by: YunQiang Su <syq@debian.org>

applied to mips-next.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]