* ether_addr_equal_64bits breakage with gcc-12
@ 2022-02-11 14:12 Marc Kleine-Budde
2022-02-12 0:35 ` Jakub Kicinski
0 siblings, 1 reply; 4+ messages in thread
From: Marc Kleine-Budde @ 2022-02-11 14:12 UTC (permalink / raw)
To: Eric Dumazet; +Cc: netdev, Jakub Kicinski, David S. Miller
[-- Attachment #1: Type: text/plain, Size: 4959 bytes --]
Hello,
the current arm-linux-gnueabihf-gcc 12 snapshot in Debian breaks (at
least with CONFIG_WERROR=y):
| CC net/core/dev.o
| net/core/dev.c: In function ‘bpf_prog_run_generic_xdp’:
| net/core/dev.c:4618:21: warning: ‘ether_addr_equal_64bits’ reading 8 bytes from a region of size 6 [-Wstringop-overread]
| 4618 | orig_host = ether_addr_equal_64bits(eth->h_dest, skb->dev->dev_addr);
| | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| net/core/dev.c:4618:21: note: referencing argument 1 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
| net/core/dev.c:4618:21: note: referencing argument 2 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
| In file included from net/core/dev.c:91:
| include/linux/etherdevice.h:375:20: note: in a call to function ‘ether_addr_equal_64bits’
| 375 | static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
| | ^~~~~~~~~~~~~~~~~~~~~~~
| net/core/dev.c:4619:22: warning: ‘is_multicast_ether_addr_64bits’ reading 8 bytes from a region of size 6 [-Wstringop-overread]
| 4619 | orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
| | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| net/core/dev.c:4619:22: note: referencing argument 1 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
| include/linux/etherdevice.h:137:20: note: in a call to function ‘is_multicast_ether_addr_64bits’
| 137 | static inline bool is_multicast_ether_addr_64bits(const u8 addr[6+2])
| | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| net/core/dev.c:4646:27: warning: ‘ether_addr_equal_64bits’ reading 8 bytes from a region of size 6 [-Wstringop-overread]
| 4646 | (orig_host != ether_addr_equal_64bits(eth->h_dest,
| | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| 4647 | skb->dev->dev_addr)) ||
| | ~~~~~~~~~~~~~~~~~~~
| net/core/dev.c:4646:27: note: referencing argument 1 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
| net/core/dev.c:4646:27: note: referencing argument 2 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
| include/linux/etherdevice.h:375:20: note: in a call to function ‘ether_addr_equal_64bits’
| 375 | static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
| | ^~~~~~~~~~~~~~~~~~~~~~~
| net/core/dev.c:4648:28: warning: ‘is_multicast_ether_addr_64bits’ reading 8 bytes from a region of size 6 [-Wstringop-overread]
| 4648 | (orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
| | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| net/core/dev.c:4648:28: note: referencing argument 1 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
| include/linux/etherdevice.h:137:20: note: in a call to function ‘is_multicast_ether_addr_64bits’
| 137 | static inline bool is_multicast_ether_addr_64bits(const u8 addr[6+2])
| | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| arm-linux-gnueabihf-gcc -v
| Using built-in specs.
| COLLECT_GCC=/usr/bin/arm-linux-gnueabihf-gcc
| COLLECT_LTO_WRAPPER=/usr/lib/gcc-cross/arm-linux-gnueabihf/12/lto-wrapper
| Target: arm-linux-gnueabihf
| Configured with: ../src/configure -v --with-pkgversion='Debian 12-20220126-1' --with-bugurl=file:///usr/share/doc/gcc-12/README.Bugs --enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-12 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-libitm --disable-libquadmath --disable-libquadmath-support --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --without-target-system-zlib --enable-multiarch --disable-sjlj-exceptions --with-arch=armv7-a+fp --with-float=hard --with-mode=thumb --disable-werror --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=arm-linux-gnueabihf --program-prefix=arm-linux-gnueabihf- --includedir=/usr/arm-linux-gnueabihf/include
| Thread model: posix
| Supported LTO compression algorithms: zlib zstd
| gcc version 12.0.1 20220126 (experimental) [master r12-6872-gf3e6ef7d873] (Debian 12-20220126-1)
regards,
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: ether_addr_equal_64bits breakage with gcc-12
2022-02-11 14:12 ether_addr_equal_64bits breakage with gcc-12 Marc Kleine-Budde
@ 2022-02-12 0:35 ` Jakub Kicinski
2022-02-12 1:31 ` Kees Cook
0 siblings, 1 reply; 4+ messages in thread
From: Jakub Kicinski @ 2022-02-12 0:35 UTC (permalink / raw)
To: Marc Kleine-Budde, Kees Cook; +Cc: Eric Dumazet, netdev, David S. Miller
On Fri, 11 Feb 2022 15:12:13 +0100 Marc Kleine-Budde wrote:
> Hello,
>
> the current arm-linux-gnueabihf-gcc 12 snapshot in Debian breaks (at
> least with CONFIG_WERROR=y):
>
> | CC net/core/dev.o
> | net/core/dev.c: In function ‘bpf_prog_run_generic_xdp’:
> | net/core/dev.c:4618:21: warning: ‘ether_addr_equal_64bits’ reading 8 bytes from a region of size 6 [-Wstringop-overread]
> | 4618 | orig_host = ether_addr_equal_64bits(eth->h_dest, skb->dev->dev_addr);
> | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> | net/core/dev.c:4618:21: note: referencing argument 1 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
> | net/core/dev.c:4618:21: note: referencing argument 2 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
> | In file included from net/core/dev.c:91:
> | include/linux/etherdevice.h:375:20: note: in a call to function ‘ether_addr_equal_64bits’
> | 375 | static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
> | | ^~~~~~~~~~~~~~~~~~~~~~~
> | net/core/dev.c:4619:22: warning: ‘is_multicast_ether_addr_64bits’ reading 8 bytes from a region of size 6 [-Wstringop-overread]
> | 4619 | orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
> | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> | net/core/dev.c:4619:22: note: referencing argument 1 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
> | include/linux/etherdevice.h:137:20: note: in a call to function ‘is_multicast_ether_addr_64bits’
> | 137 | static inline bool is_multicast_ether_addr_64bits(const u8 addr[6+2])
> | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> | net/core/dev.c:4646:27: warning: ‘ether_addr_equal_64bits’ reading 8 bytes from a region of size 6 [-Wstringop-overread]
> | 4646 | (orig_host != ether_addr_equal_64bits(eth->h_dest,
> | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> | 4647 | skb->dev->dev_addr)) ||
> | | ~~~~~~~~~~~~~~~~~~~
> | net/core/dev.c:4646:27: note: referencing argument 1 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
> | net/core/dev.c:4646:27: note: referencing argument 2 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
> | include/linux/etherdevice.h:375:20: note: in a call to function ‘ether_addr_equal_64bits’
> | 375 | static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
> | | ^~~~~~~~~~~~~~~~~~~~~~~
> | net/core/dev.c:4648:28: warning: ‘is_multicast_ether_addr_64bits’ reading 8 bytes from a region of size 6 [-Wstringop-overread]
> | 4648 | (orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
> | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> | net/core/dev.c:4648:28: note: referencing argument 1 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
> | include/linux/etherdevice.h:137:20: note: in a call to function ‘is_multicast_ether_addr_64bits’
> | 137 | static inline bool is_multicast_ether_addr_64bits(const u8 addr[6+2])
> | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> | arm-linux-gnueabihf-gcc -v
> | Using built-in specs.
> | COLLECT_GCC=/usr/bin/arm-linux-gnueabihf-gcc
> | COLLECT_LTO_WRAPPER=/usr/lib/gcc-cross/arm-linux-gnueabihf/12/lto-wrapper
> | Target: arm-linux-gnueabihf
> | Configured with: ../src/configure -v --with-pkgversion='Debian 12-20220126-1' --with-bugurl=file:///usr/share/doc/gcc-12/README.Bugs --enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-12 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-libitm --disable-libquadmath --disable-libquadmath-support --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --without-target-system-zlib --enable-multiarch --disable-sjlj-exceptions --with-arch=armv7-a+fp --with-float=hard --with-mode=thumb --disable-werror --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=arm-linux-gnueabihf --program-prefix=arm-linux-gnueabihf- --includedir=/usr/arm-linux-gnueabihf/include
> | Thread model: posix
> | Supported LTO compression algorithms: zlib zstd
> | gcc version 12.0.1 20220126 (experimental) [master r12-6872-gf3e6ef7d873] (Debian 12-20220126-1)
Maybe Kees will have as suggestion - Kees, are there any best practices
for dealing with such issues? For the reference we do a oversized load
from a structure (read 8B of a 6B array):
struct ethhdr {
unsigned char h_dest[6];
unsigned char h_source[6];
__be16 h_proto;
} __attribute__((packed));
But then discard the irrelevant bytes:
#if defined(CONFIG_HAVE_EFFICIENT...
u64 fold = (*(const u64 *)addr1) ^ (*(const u64 *)addr2);
#ifdef __BIG_ENDIAN
return (fold >> 16) == 0;
#else ...
The structure is uAPI, for added fun.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: ether_addr_equal_64bits breakage with gcc-12
2022-02-12 0:35 ` Jakub Kicinski
@ 2022-02-12 1:31 ` Kees Cook
2022-02-12 9:08 ` Marc Kleine-Budde
0 siblings, 1 reply; 4+ messages in thread
From: Kees Cook @ 2022-02-12 1:31 UTC (permalink / raw)
To: Jakub Kicinski; +Cc: Marc Kleine-Budde, Eric Dumazet, netdev, David S. Miller
On Fri, Feb 11, 2022 at 04:35:41PM -0800, Jakub Kicinski wrote:
> On Fri, 11 Feb 2022 15:12:13 +0100 Marc Kleine-Budde wrote:
> > Hello,
> >
> > the current arm-linux-gnueabihf-gcc 12 snapshot in Debian breaks (at
> > least with CONFIG_WERROR=y):
> >
> > | CC net/core/dev.o
> > | net/core/dev.c: In function ‘bpf_prog_run_generic_xdp’:
> > | net/core/dev.c:4618:21: warning: ‘ether_addr_equal_64bits’ reading 8 bytes from a region of size 6 [-Wstringop-overread]
> > | 4618 | orig_host = ether_addr_equal_64bits(eth->h_dest, skb->dev->dev_addr);
> > | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > | net/core/dev.c:4618:21: note: referencing argument 1 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
> > | net/core/dev.c:4618:21: note: referencing argument 2 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
> > | In file included from net/core/dev.c:91:
> > | include/linux/etherdevice.h:375:20: note: in a call to function ‘ether_addr_equal_64bits’
> > | 375 | static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
> > | | ^~~~~~~~~~~~~~~~~~~~~~~
> > | net/core/dev.c:4619:22: warning: ‘is_multicast_ether_addr_64bits’ reading 8 bytes from a region of size 6 [-Wstringop-overread]
> > | 4619 | orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
> > | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > | net/core/dev.c:4619:22: note: referencing argument 1 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
> > | include/linux/etherdevice.h:137:20: note: in a call to function ‘is_multicast_ether_addr_64bits’
> > | 137 | static inline bool is_multicast_ether_addr_64bits(const u8 addr[6+2])
> > | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > | net/core/dev.c:4646:27: warning: ‘ether_addr_equal_64bits’ reading 8 bytes from a region of size 6 [-Wstringop-overread]
> > | 4646 | (orig_host != ether_addr_equal_64bits(eth->h_dest,
> > | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > | 4647 | skb->dev->dev_addr)) ||
> > | | ~~~~~~~~~~~~~~~~~~~
> > | net/core/dev.c:4646:27: note: referencing argument 1 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
> > | net/core/dev.c:4646:27: note: referencing argument 2 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
> > | include/linux/etherdevice.h:375:20: note: in a call to function ‘ether_addr_equal_64bits’
> > | 375 | static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
> > | | ^~~~~~~~~~~~~~~~~~~~~~~
> > | net/core/dev.c:4648:28: warning: ‘is_multicast_ether_addr_64bits’ reading 8 bytes from a region of size 6 [-Wstringop-overread]
> > | 4648 | (orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
> > | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > | net/core/dev.c:4648:28: note: referencing argument 1 of type ‘const u8[8]’ {aka ‘const unsigned char[8]’}
> > | include/linux/etherdevice.h:137:20: note: in a call to function ‘is_multicast_ether_addr_64bits’
> > | 137 | static inline bool is_multicast_ether_addr_64bits(const u8 addr[6+2])
> > | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >
> > | arm-linux-gnueabihf-gcc -v
> > | Using built-in specs.
> > | COLLECT_GCC=/usr/bin/arm-linux-gnueabihf-gcc
> > | COLLECT_LTO_WRAPPER=/usr/lib/gcc-cross/arm-linux-gnueabihf/12/lto-wrapper
> > | Target: arm-linux-gnueabihf
> > | Configured with: ../src/configure -v --with-pkgversion='Debian 12-20220126-1' --with-bugurl=file:///usr/share/doc/gcc-12/README.Bugs --enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-12 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-libitm --disable-libquadmath --disable-libquadmath-support --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --without-target-system-zlib --enable-multiarch --disable-sjlj-exceptions --with-arch=armv7-a+fp --with-float=hard --with-mode=thumb --disable-werror --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=arm-linux-gnueabihf --program-prefix=arm-linux-gnueabihf- --includedir=/usr/arm-linux-gnueabihf/include
> > | Thread model: posix
> > | Supported LTO compression algorithms: zlib zstd
> > | gcc version 12.0.1 20220126 (experimental) [master r12-6872-gf3e6ef7d873] (Debian 12-20220126-1)
>
> Maybe Kees will have as suggestion - Kees, are there any best practices
> for dealing with such issues? For the reference we do a oversized load
> from a structure (read 8B of a 6B array):
Wheee.
So, the short theoretical "don't do that" scenario would be "what
happens if":
struct page *page;
void *ptr;
unsigned char *eth_addr;
page = alloc_pages(GFP_KERNEL, 0);
...
ptr = page_address(page);
...
/* "eth_addr" at end of allocated memory */
eth_addr = ptr + PAGE_SIZE - 6;
/* access fault... */
ether_addr_equal_64bits(eth_addr, ...);
But, yes, pragmatically, this is likely extremely rare.
Regardless, with the other cases like this that got fixed like this, it
was a matter of finding a way to represent the "actual" available memory
(best), or telling the compiler what real contract is (less good).
It looks like alignment isn't a concern, so I'd say adjust the prototype
to reflect the reality, and go with:
diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h
index 2ad71cc90b37..92b10e67d5f8 100644
--- a/include/linux/etherdevice.h
+++ b/include/linux/etherdevice.h
@@ -134,7 +134,7 @@ static inline bool is_multicast_ether_addr(const u8 *addr)
#endif
}
-static inline bool is_multicast_ether_addr_64bits(const u8 addr[6+2])
+static inline bool is_multicast_ether_addr_64bits(const u8 *addr)
{
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
#ifdef __BIG_ENDIAN
@@ -372,8 +372,7 @@ static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
* Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits.
*/
-static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
- const u8 addr2[6+2])
+static inline bool ether_addr_equal_64bits(const u8 *addr1, const u8 *addr2)
{
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
u64 fold = (*(const u64 *)addr1) ^ (*(const u64 *)addr2);
--
Kees Cook
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: ether_addr_equal_64bits breakage with gcc-12
2022-02-12 1:31 ` Kees Cook
@ 2022-02-12 9:08 ` Marc Kleine-Budde
0 siblings, 0 replies; 4+ messages in thread
From: Marc Kleine-Budde @ 2022-02-12 9:08 UTC (permalink / raw)
To: Kees Cook; +Cc: Jakub Kicinski, Eric Dumazet, netdev, David S. Miller
[-- Attachment #1: Type: text/plain, Size: 2559 bytes --]
On 11.02.2022 17:31:22, Kees Cook wrote:
> > Maybe Kees will have as suggestion - Kees, are there any best practices
> > for dealing with such issues? For the reference we do a oversized load
> > from a structure (read 8B of a 6B array):
>
> Wheee.
>
> So, the short theoretical "don't do that" scenario would be "what
> happens if":
>
> struct page *page;
> void *ptr;
> unsigned char *eth_addr;
>
> page = alloc_pages(GFP_KERNEL, 0);
> ...
> ptr = page_address(page);
> ...
> /* "eth_addr" at end of allocated memory */
> eth_addr = ptr + PAGE_SIZE - 6;
> /* access fault... */
> ether_addr_equal_64bits(eth_addr, ...);
>
> But, yes, pragmatically, this is likely extremely rare.
>
> Regardless, with the other cases like this that got fixed like this, it
> was a matter of finding a way to represent the "actual" available memory
> (best), or telling the compiler what real contract is (less good).
>
> It looks like alignment isn't a concern, so I'd say adjust the prototype
> to reflect the reality, and go with:
>
>
> diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h
> index 2ad71cc90b37..92b10e67d5f8 100644
> --- a/include/linux/etherdevice.h
> +++ b/include/linux/etherdevice.h
> @@ -134,7 +134,7 @@ static inline bool is_multicast_ether_addr(const u8 *addr)
> #endif
> }
>
> -static inline bool is_multicast_ether_addr_64bits(const u8 addr[6+2])
> +static inline bool is_multicast_ether_addr_64bits(const u8 *addr)
> {
> #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
> #ifdef __BIG_ENDIAN
> @@ -372,8 +372,7 @@ static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
> * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits.
> */
>
> -static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
> - const u8 addr2[6+2])
> +static inline bool ether_addr_equal_64bits(const u8 *addr1, const u8 *addr2)
> {
> #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
> u64 fold = (*(const u64 *)addr1) ^ (*(const u64 *)addr2);
>
With that patch the warning is gone.
Tested-by: Marc Kleine-Budde <mkl@pengutronix.de>
regards,
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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2022-02-11 14:12 ether_addr_equal_64bits breakage with gcc-12 Marc Kleine-Budde
2022-02-12 0:35 ` Jakub Kicinski
2022-02-12 1:31 ` Kees Cook
2022-02-12 9:08 ` Marc Kleine-Budde
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