tree: https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git for-next/lkdtm
head: 2e53b877dc1258d4ac3de98f496bb88ec3bf5e25
commit: 2e53b877dc1258d4ac3de98f496bb88ec3bf5e25 [6/6] lkdtm: Add CFI_BACKWARD to test ROP mitigations
config: sparc-randconfig-r026-20220417 (https://download.01.org/0day-ci/archive/20220417/[email protected]/config)
compiler: sparc-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/commit/?id=2e53b877dc1258d4ac3de98f496bb88ec3bf5e25
git remote add kees https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git
git fetch --no-tags kees for-next/lkdtm
git checkout 2e53b877dc1258d4ac3de98f496bb88ec3bf5e25
# save the config file to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=sparc SHELL=/bin/bash drivers/misc/lkdtm/
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>
All warnings (new ones prefixed by >>):
drivers/misc/lkdtm/cfi.c: In function 'set_return_addr_unchecked':
>> drivers/misc/lkdtm/cfi.c:62:37: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
62 | ((__force __typeof__(addr))((__force u64)(addr) | PAGE_OFFSET))
| ^
drivers/misc/lkdtm/cfi.c:72:13: note: in expansion of macro 'no_pac_addr'
72 | if (no_pac_addr(*ret_addr) == expected)
| ^~~~~~~~~~~
>> drivers/misc/lkdtm/cfi.c:62:10: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
62 | ((__force __typeof__(addr))((__force u64)(addr) | PAGE_OFFSET))
| ^
drivers/misc/lkdtm/cfi.c:72:13: note: in expansion of macro 'no_pac_addr'
72 | if (no_pac_addr(*ret_addr) == expected)
| ^~~~~~~~~~~
drivers/misc/lkdtm/cfi.c: In function 'set_return_addr':
>> drivers/misc/lkdtm/cfi.c:62:37: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
62 | ((__force __typeof__(addr))((__force u64)(addr) | PAGE_OFFSET))
| ^
drivers/misc/lkdtm/cfi.c:87:13: note: in expansion of macro 'no_pac_addr'
87 | if (no_pac_addr(*ret_addr) == expected)
| ^~~~~~~~~~~
>> drivers/misc/lkdtm/cfi.c:62:10: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
62 | ((__force __typeof__(addr))((__force u64)(addr) | PAGE_OFFSET))
| ^
drivers/misc/lkdtm/cfi.c:87:13: note: in expansion of macro 'no_pac_addr'
87 | if (no_pac_addr(*ret_addr) == expected)
| ^~~~~~~~~~~
vim +62 drivers/misc/lkdtm/cfi.c
60
61 #define no_pac_addr(addr) \
> 62 ((__force __typeof__(addr))((__force u64)(addr) | PAGE_OFFSET))
63
--
0-DAY CI Kernel Test Service
https://01.org/lkp
On Sun, Apr 17, 2022 at 07:26:33AM +0800, kernel test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git for-next/lkdtm
> head: 2e53b877dc1258d4ac3de98f496bb88ec3bf5e25
> commit: 2e53b877dc1258d4ac3de98f496bb88ec3bf5e25 [6/6] lkdtm: Add CFI_BACKWARD to test ROP mitigations
> config: sparc-randconfig-r026-20220417 (https://download.01.org/0day-ci/archive/20220417/[email protected]/config)
> compiler: sparc-linux-gcc (GCC) 11.2.0
> reproduce (this is a W=1 build):
> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/commit/?id=2e53b877dc1258d4ac3de98f496bb88ec3bf5e25
> git remote add kees https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git
> git fetch --no-tags kees for-next/lkdtm
> git checkout 2e53b877dc1258d4ac3de98f496bb88ec3bf5e25
> # save the config file to linux build tree
> mkdir build_dir
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=sparc SHELL=/bin/bash drivers/misc/lkdtm/
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <[email protected]>
>
> All warnings (new ones prefixed by >>):
>
> drivers/misc/lkdtm/cfi.c: In function 'set_return_addr_unchecked':
> >> drivers/misc/lkdtm/cfi.c:62:37: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
> 62 | ((__force __typeof__(addr))((__force u64)(addr) | PAGE_OFFSET))
> | ^
> drivers/misc/lkdtm/cfi.c:72:13: note: in expansion of macro 'no_pac_addr'
> 72 | if (no_pac_addr(*ret_addr) == expected)
> | ^~~~~~~~~~~
Hmm. I don't see why this is warning. The macro looks like untagged_addr():
#define untagged_addr(addr) ({ \
u64 __addr = (__force u64)(addr); \
__addr &= __untagged_addr(__addr); \
(__force __typeof__(addr))__addr; \
})
--
Kees Cook
Hi Kees,
On Tue, Apr 19, 2022 at 9:20 PM Kees Cook <[email protected]> wrote:
> On Sun, Apr 17, 2022 at 07:26:33AM +0800, kernel test robot wrote:
> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git for-next/lkdtm
> > head: 2e53b877dc1258d4ac3de98f496bb88ec3bf5e25
> > commit: 2e53b877dc1258d4ac3de98f496bb88ec3bf5e25 [6/6] lkdtm: Add CFI_BACKWARD to test ROP mitigations
> > config: sparc-randconfig-r026-20220417 (https://download.01.org/0day-ci/archive/20220417/[email protected]/config)
Just received a failure for m68k-allmodconfig on next-20220426:
drivers/misc/lkdtm/cfi.c:62:37: error: cast from pointer to integer of
different size [-Werror=pointer-to-int-cast]
drivers/misc/lkdtm/cfi.c:62:10: error: cast to pointer from integer of
different size [-Werror=int-to-pointer-cast]
drivers/misc/lkdtm/cfi.c:62:37: error: cast from pointer to integer of
different size [-Werror=pointer-to-int-cast]
drivers/misc/lkdtm/cfi.c:62:10: error: cast to pointer from integer of
different size [-Werror=int-to-pointer-cast]
> > compiler: sparc-linux-gcc (GCC) 11.2.0
> > reproduce (this is a W=1 build):
> > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> > chmod +x ~/bin/make.cross
> > # https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/commit/?id=2e53b877dc1258d4ac3de98f496bb88ec3bf5e25
> > git remote add kees https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git
> > git fetch --no-tags kees for-next/lkdtm
> > git checkout 2e53b877dc1258d4ac3de98f496bb88ec3bf5e25
> > # save the config file to linux build tree
> > mkdir build_dir
> > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=sparc SHELL=/bin/bash drivers/misc/lkdtm/
> >
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <[email protected]>
> >
> > All warnings (new ones prefixed by >>):
> >
> > drivers/misc/lkdtm/cfi.c: In function 'set_return_addr_unchecked':
> > >> drivers/misc/lkdtm/cfi.c:62:37: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
> > 62 | ((__force __typeof__(addr))((__force u64)(addr) | PAGE_OFFSET))
> > | ^
> > drivers/misc/lkdtm/cfi.c:72:13: note: in expansion of macro 'no_pac_addr'
> > 72 | if (no_pac_addr(*ret_addr) == expected)
> > | ^~~~~~~~~~~
>
> Hmm. I don't see why this is warning. The macro looks like untagged_addr():
>
> #define untagged_addr(addr) ({ \
> u64 __addr = (__force u64)(addr); \
> __addr &= __untagged_addr(__addr); \
> (__force __typeof__(addr))__addr; \
> })
The offending macro is:
#define no_pac_addr(addr) \
((__force __typeof__(addr))((__force u64)(addr) | PAGE_OFFSET))
On 32-bit, addr is a 32-bit pointer, which is cast to a 64-bit integer first,
then to a 32-bit pointer again.
All of these need intermediate casts to uintptr_t.
oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
On Tue, Apr 26, 2022 at 03:03:33PM +0200, Geert Uytterhoeven wrote:
> On Tue, Apr 19, 2022 at 9:20 PM Kees Cook <[email protected]> wrote:
> > On Sun, Apr 17, 2022 at 07:26:33AM +0800, kernel test robot wrote:
> > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git for-next/lkdtm
> > > head: 2e53b877dc1258d4ac3de98f496bb88ec3bf5e25
> > > commit: 2e53b877dc1258d4ac3de98f496bb88ec3bf5e25 [6/6] lkdtm: Add CFI_BACKWARD to test ROP mitigations
> > > config: sparc-randconfig-r026-20220417 (https://download.01.org/0day-ci/archive/20220417/[email protected]/config)
>
> Just received a failure for m68k-allmodconfig on next-20220426:
>
> drivers/misc/lkdtm/cfi.c:62:37: error: cast from pointer to integer of
> different size [-Werror=pointer-to-int-cast]
> drivers/misc/lkdtm/cfi.c:62:10: error: cast to pointer from integer of
> different size [-Werror=int-to-pointer-cast]
> drivers/misc/lkdtm/cfi.c:62:37: error: cast from pointer to integer of
> different size [-Werror=pointer-to-int-cast]
> drivers/misc/lkdtm/cfi.c:62:10: error: cast to pointer from integer of
> different size [-Werror=int-to-pointer-cast]
>
> > > compiler: sparc-linux-gcc (GCC) 11.2.0
> > > reproduce (this is a W=1 build):
> > > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> > > chmod +x ~/bin/make.cross
> > > # https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/commit/?id=2e53b877dc1258d4ac3de98f496bb88ec3bf5e25
> > > git remote add kees https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git
> > > git fetch --no-tags kees for-next/lkdtm
> > > git checkout 2e53b877dc1258d4ac3de98f496bb88ec3bf5e25
> > > # save the config file to linux build tree
> > > mkdir build_dir
> > > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=sparc SHELL=/bin/bash drivers/misc/lkdtm/
> > >
> > > If you fix the issue, kindly add following tag as appropriate
> > > Reported-by: kernel test robot <[email protected]>
> > >
> > > All warnings (new ones prefixed by >>):
> > >
> > > drivers/misc/lkdtm/cfi.c: In function 'set_return_addr_unchecked':
> > > >> drivers/misc/lkdtm/cfi.c:62:37: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
> > > 62 | ((__force __typeof__(addr))((__force u64)(addr) | PAGE_OFFSET))
> > > | ^
> > > drivers/misc/lkdtm/cfi.c:72:13: note: in expansion of macro 'no_pac_addr'
> > > 72 | if (no_pac_addr(*ret_addr) == expected)
> > > | ^~~~~~~~~~~
> >
> > Hmm. I don't see why this is warning. The macro looks like untagged_addr():
> >
> > #define untagged_addr(addr) ({ \
> > u64 __addr = (__force u64)(addr); \
> > __addr &= __untagged_addr(__addr); \
> > (__force __typeof__(addr))__addr; \
> > })
>
> The offending macro is:
>
> #define no_pac_addr(addr) \
> ((__force __typeof__(addr))((__force u64)(addr) | PAGE_OFFSET))
>
> On 32-bit, addr is a 32-bit pointer, which is cast to a 64-bit integer first,
> then to a 32-bit pointer again.
> All of these need intermediate casts to uintptr_t.
As in this?
#define no_pac_addr(addr) \
((__force __typeof__(addr))((uintptr_t)(addr) | PAGE_OFFSET))
--
Kees Cook