Re: [PATCH 3/3] powerpc: Fix pre-update addressing in inline assembly

From: Christophe Leroy
Date: Mon Oct 19 2020 - 14:24:05 EST




Le 19/10/2020 à 17:35, kernel test robot a écrit :
Hi Christophe,

I love your patch! Yet something to improve:

[auto build test ERROR on powerpc/next]
[also build test ERROR on linus/master next-20201016]
[cannot apply to kvm-ppc/kvm-ppc-next mpe/next v5.9]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url: https://github.com/0day-ci/linux/commits/Christophe-Leroy/powerpc-uaccess-Don-t-use-m-constraint-with-GCC-4-9/20201019-201504
base: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc64-randconfig-r012-20201019 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 094e9f4779eb9b5c6a49014f2f80b8cbb833572f)
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
# install powerpc64 cross compiling tool for clang build
# apt-get install binutils-powerpc64-linux-gnu
# https://github.com/0day-ci/linux/commit/d57fd8d270993414b8c0414d7be4b03cc3de1856
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Christophe-Leroy/powerpc-uaccess-Don-t-use-m-constraint-with-GCC-4-9/20201019-201504
git checkout d57fd8d270993414b8c0414d7be4b03cc3de1856
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc64

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All errors (new ones prefixed by >>):

In file included from arch/powerpc/kernel/asm-offsets.c:14:
In file included from include/linux/compat.h:14:
In file included from include/linux/sem.h:5:
In file included from include/uapi/linux/sem.h:5:
In file included from include/linux/ipc.h:5:
In file included from include/linux/spinlock.h:51:
In file included from include/linux/preempt.h:78:
In file included from ./arch/powerpc/include/generated/asm/preempt.h:1:
In file included from include/asm-generic/preempt.h:5:
In file included from include/linux/thread_info.h:21:
In file included from arch/powerpc/include/asm/current.h:13:
In file included from arch/powerpc/include/asm/paca.h:31:
In file included from arch/powerpc/include/asm/atomic.h:13:
In file included from arch/powerpc/include/asm/ppc_asm.h:9:
In file included from arch/powerpc/include/asm/processor.h:40:
arch/powerpc/include/asm/ptrace.h:288:20: error: use of undeclared identifier 'THREAD_SIZE'
return ((addr & ~(THREAD_SIZE - 1)) ==
^
arch/powerpc/include/asm/ptrace.h:289:35: error: use of undeclared identifier 'THREAD_SIZE'
(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));

Most likely a circular inclusion problem.

I'll have to put it in a header that doesn't include pile of other stuff. The least bad candidate seems to be asm-const.h

Christophe

^
In file included from arch/powerpc/kernel/asm-offsets.c:21:
include/linux/mman.h:137:9: warning: division by zero is undefined [-Wdivision-by-zero]
_calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) |
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/mman.h:115:21: note: expanded from macro '_calc_vm_trans'
: ((x) & (bit1)) / ((bit1) / (bit2))))
^ ~~~~~~~~~~~~~~~~~
include/linux/mman.h:138:9: warning: division by zero is undefined [-Wdivision-by-zero]
_calc_vm_trans(flags, MAP_SYNC, VM_SYNC );
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/mman.h:115:21: note: expanded from macro '_calc_vm_trans'
: ((x) & (bit1)) / ((bit1) / (bit2))))
^ ~~~~~~~~~~~~~~~~~
2 warnings and 2 errors generated.
make[2]: *** [scripts/Makefile.build:117: arch/powerpc/kernel/asm-offsets.s] Error 1
make[2]: Target '__build' not remade because of errors.
make[1]: *** [Makefile:1202: prepare0] Error 2
make[1]: Target 'prepare' not remade because of errors.
make: *** [Makefile:185: __sub-make] Error 2
make: Target 'prepare' not remade because of errors.

vim +/THREAD_SIZE +288 arch/powerpc/include/asm/ptrace.h

359e4284a3f37ab Mahesh Salgaonkar 2010-04-07 275
359e4284a3f37ab Mahesh Salgaonkar 2010-04-07 276 /**
359e4284a3f37ab Mahesh Salgaonkar 2010-04-07 277 * regs_within_kernel_stack() - check the address in the stack
359e4284a3f37ab Mahesh Salgaonkar 2010-04-07 278 * @regs: pt_regs which contains kernel stack pointer.
359e4284a3f37ab Mahesh Salgaonkar 2010-04-07 279 * @addr: address which is checked.
359e4284a3f37ab Mahesh Salgaonkar 2010-04-07 280 *
359e4284a3f37ab Mahesh Salgaonkar 2010-04-07 281 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
359e4284a3f37ab Mahesh Salgaonkar 2010-04-07 282 * If @addr is within the kernel stack, it returns true. If not, returns false.
359e4284a3f37ab Mahesh Salgaonkar 2010-04-07 283 */
359e4284a3f37ab Mahesh Salgaonkar 2010-04-07 284
359e4284a3f37ab Mahesh Salgaonkar 2010-04-07 285 static inline bool regs_within_kernel_stack(struct pt_regs *regs,
359e4284a3f37ab Mahesh Salgaonkar 2010-04-07 286 unsigned long addr)
359e4284a3f37ab Mahesh Salgaonkar 2010-04-07 287 {
359e4284a3f37ab Mahesh Salgaonkar 2010-04-07 @288 return ((addr & ~(THREAD_SIZE - 1)) ==
359e4284a3f37ab Mahesh Salgaonkar 2010-04-07 289 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
359e4284a3f37ab Mahesh Salgaonkar 2010-04-07 290 }
359e4284a3f37ab Mahesh Salgaonkar 2010-04-07 291

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