Re: [PATCH] consistently use MAX_ERRNO in __syscall_return

["H. Peter Anvin" <hpa@zytor.com>]

Randy.Dunlap wrote:
>>>>  
>>>>  #define NR_syscalls 318
>>>> +#include <linux/err.h>
>>> include/linux/err.h: Assembler messages:
>>> include/linux/err.h:20: Error: no such instruction: `static inline void *ERR_PTR(long error)'
>>> include/linux/err.h:21: Error: junk at end of line, first unrecognized character is `{'
>>> include/linux/err.h:22: Error: no such instruction: `return (void *)error'
>>> include/linux/err.h:23: Error: junk at end of line, first unrecognized character is `}'
>>> include/linux/err.h:25: Error: no such instruction: `static inline long PTR_ERR(const void *ptr)'
>>> include/linux/err.h:26: Error: junk at end of line, first unrecognized character is `{'
>>> include/linux/err.h:27: Error: no such instruction: `return (long)ptr'
>>> include/linux/err.h:28: Error: junk at end of line, first unrecognized character is `}'
>>> include/linux/err.h:30: Error: no such instruction: `static inline long IS_ERR(const void *ptr)'
>>> include/linux/err.h:31: Error: junk at end of line, first unrecognized character is `{'
>>> include/linux/err.h:32: Error: no such instruction: `return unlikely(((unsigned long)ptr)>=(unsigned long)-4095)'
>>> include/linux/err.h:33: Error: junk at end of line, first unrecognized character is `}'
>>> distcc[7619] ERROR: compile (null) on localhost failed
>>> make[1]: *** [arch/i386/kernel/vsyscall-sysenter.o] Error 1
>>> make: *** [arch/i386/kernel/vsyscall-sysenter.o] Error 2
> 
> Built for me on i386 and x86_64.
> 
>> unlikely() shouldn't be used in code exported to user space.  At least 
>> one architecture simply open-codes the __builtin_expect(); or we could
>> introduce __likely() and __unlikely() for the benefit of userspace.
> 
> How did you determine that this had something to do with
> userspace?
> 

The vsyscalls are userspace code.  Doesn't mean they operate by 
userspace naming rules, of course, but still...

	-hpa