Messages in this thread | | | From | Jann Horn <> | Date | Thu, 15 Oct 2020 23:46:26 +0200 | Subject | Re: [linux-stable-rc:linux-5.4.y 665/2391] drivers/android/binder.c:3776: Error: unrecognized keyword/register name `l.lwz |
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+openrisc folks
On Thu, Oct 15, 2020 at 11:28 PM kernel test robot <lkp@intel.com> wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-5.4.y > head: 85b0841aab15c12948af951d477183ab3df7de14 > commit: c5665cafbedd2e2a523fe933e452391a02d3adb3 [665/2391] binder: Prevent context manager from incrementing ref 0 > config: openrisc-randconfig-r002-20201014 (attached as .config) > compiler: or1k-linux-gcc (GCC) 9.3.0 > 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/stable/linux-stable-rc.git/commit/?id=c5665cafbedd2e2a523fe933e452391a02d3adb3 > git remote add linux-stable-rc https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git > git fetch --no-tags linux-stable-rc linux-5.4.y > git checkout c5665cafbedd2e2a523fe933e452391a02d3adb3 > # save the attached .config to linux build tree > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=openrisc > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <lkp@intel.com> > > All errors (new ones prefixed by >>): > > drivers/android/binder.c: Assembler messages: > >> drivers/android/binder.c:3776: Error: unrecognized keyword/register name `l.lwz ?ap,4(r25)' > drivers/android/binder.c:3781: Error: unrecognized keyword/register name `l.addi ?ap,r0,0'
binder is basically doing this:
u64 data_ptr; if (get_user(data_ptr, (u64 __user *)ptr)) return -EFAULT;
and GCC complains that that doesn't turn into valid assembly on openrisc, where get_user() of size 8 expands into this:
#define __get_user_asm2(x, addr, err) \ { \ unsigned long long __gu_tmp; \ __asm__ __volatile__( \ "1: l.lwz %1,0(%2)\n" \ "2: l.lwz %H1,4(%2)\n" \ "3:\n" \ ".section .fixup,\"ax\"\n" \ "4: l.addi %0,r0,%3\n" \ " l.addi %1,r0,0\n" \ " l.addi %H1,r0,0\n" \ " l.j 3b\n" \ " l.nop\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n" \ " .align 2\n" \ " .long 1b,4b\n" \ " .long 2b,4b\n" \ ".previous" \ : "=r"(err), "=&r"(__gu_tmp) \ : "r"(addr), "i"(-EFAULT), "0"(err)); \ (x) = (__typeof__(*(addr)))( \ (__typeof__((x)-(x)))__gu_tmp); \ }
and apparently the "l.lwz %H1,4(%2)" and "l.addi %H1,r0,0" don't turn into valid assembly when %H1 expands to "?ap"?
I don't know anything about OpenRISC, but this seems like it's probably an issue in the get_user() implementation.
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