Subject: linux-next: build failure after merge of the y2038 tree

From: Stephen Rothwell <[email-masked]>
Date: Tue, 27 Mar 2018 18:26:19 +1100

Hi Arnd,

After merging the y2038 tree, today's linux-next build (sparc defconfig)
failed like this:

In file included from include/linux/compat.h:22:0,
                 from arch/sparc/kernel/systbls.h:7,
                 from arch/sparc/kernel/sys_sparc_32.c:30:
arch/sparc/include/asm/compat.h: In function 'arch_compat_alloc_user_space':
arch/sparc/include/asm/compat.h:162:46: error: 'struct thread_info' has no member named 'kregs'
  struct pt_regs *regs = current_thread_info()->kregs;
                                              ^~
arch/sparc/include/asm/compat.h:165:6: error: implicit declaration of function 'test_thread_64bit_stack'; did you mean 'setup_thread_stack'? [-Werror=implicit-function-declaration]
  if (test_thread_64bit_stack(usp))
      ^~~~~~~~~~~~~~~~~~~~~~~
      setup_thread_stack
In file included from include/asm-generic/preempt.h:5:0,
                 from ./arch/sparc/include/generated/asm/preempt.h:1,
                 from include/linux/preempt.h:81,
                 from include/linux/rcupdate.h:40,
                 from include/linux/rculist.h:11,
                 from include/linux/sched/signal.h:5,
                 from arch/sparc/kernel/sys_sparc_32.c:11:
arch/sparc/include/asm/compat.h:168:23: error: 'TIF_32BIT' undeclared (first use in this function); did you mean 'MAP_32BIT'?
  if (test_thread_flag(TIF_32BIT))
                       ^
include/linux/thread_info.h:91:45: note: in definition of macro 'test_thread_flag'
  test_ti_thread_flag(current_thread_info(), flag)
                                             ^~~~
arch/sparc/include/asm/compat.h:168:23: note: each undeclared identifier is reported only once for each function it appears in
  if (test_thread_flag(TIF_32BIT))
                       ^
include/linux/thread_info.h:91:45: note: in definition of macro 'test_thread_flag'
  test_ti_thread_flag(current_thread_info(), flag)
                                             ^~~~
arch/sparc/include/asm/compat.h: In function 'is_compat_task':
arch/sparc/include/asm/compat.h:237:26: error: 'TIF_32BIT' undeclared (first use in this function); did you mean 'MAP_32BIT'?
  return test_thread_flag(TIF_32BIT);
                          ^
include/linux/thread_info.h:91:45: note: in definition of macro 'test_thread_flag'
  test_ti_thread_flag(current_thread_info(), flag)
                                             ^~~~
In file included from include/linux/compat.h:22:0,
                 from arch/sparc/kernel/systbls.h:7,
                 from arch/sparc/kernel/sys_sparc_32.c:30:
arch/sparc/include/asm/compat.h: In function 'in_compat_syscall':
arch/sparc/include/asm/compat.h:243:9: error: implicit declaration of function 'pt_regs_trap_type'; did you mean 'resource_type'? [-Werror=implicit-function-declaration]
  return pt_regs_trap_type(current_pt_regs()) == 0x110;
         ^~~~~~~~~~~~~~~~~
         resource_type

and lots more :-(

I suspect it is caused by commit

  d1a353a4a8cc ("compat: add an asm-generic/compat.h file")

It looks like the sparc asm/compat.h does not expect to be included in
32 bit builds?

I have reverted the entire y2038 tree merge for today.

-- 
Cheers,
Stephen Rothwell