From: Vincentius Robby (vincentius_at_umich_dot_edu)
Date: Wed Sep 03 2008 - 20:59:00 PDT
Hello Paul,
Ah, I'm learning a lot here..
The next step that I haven't been able to figure out is the errors
which I referenced in the previous e-mail:
then mv -f ".deps/libcr_la-cr_syscall.Tpo"
".deps/libcr_la-cr_syscall.Plo"; else rm -f
".deps/libcr_la-cr_syscall.Tpo"; exit 1; fi
gcc -DHAVE_CONFIG_H -I. -I../../libcr -I.. -D_GNU_SOURCE
-D_REENTRANT -I../include -I../../include -I../../libcr/arch/sparc/
-Wall -Wno-unused-function -fno-stack-protector -g -O2 -MT
libcr_la-cr_syscall.lo -MD -MP -MF .deps/libcr_la-cr_syscall.Tpo -c
../../libcr/cr_syscall.c -fPIC -DPIC -o .libs/libcr_la-cr_syscall.o
../../libcr/cr_syscall.c:169: error: expected ')' before 'int'
../../libcr/cr_syscall.c:170: error: expected ')' before 'const'
../../libcr/cr_syscall.c:171: error: expected ')' before 'int'
../../libcr/cr_syscall.c: In function '__cri_sched_yield':
../../libcr/cr_syscall.c:172: warning: initialization makes integer
from pointer without a cast
../../libcr/cr_syscall.c: At top level:
../../libcr/cr_syscall.c:173: error: expected ')' before 'const'
../../libcr/cr_syscall.c:174: error: expected ')' before 'int'
../../libcr/cr_syscall.c:176: error: expected ')' before 'int'
../../libcr/cr_syscall.c:183: error: expected ')' before 'int'
../../libcr/cr_syscall.c:189: error: expected ')' before 'int'
make[2]: *** [libcr_la-cr_syscall.lo] Error 1
make[2]: Leaving directory `/opt/blcr-0.7.3_vincent/builddir/libcr'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/opt/blcr-0.7.3_vincent/builddir'
make: *** [all] Error 2
Here is the snippet from cr_syscall.c
169:cri_syscall3(int, __cri_ioctl, __NR_ioctl, int, int, void*)
170:cri_syscall3(int, __cri_open, __NR_open, const char*, int, int)
171:cri_syscall1(int, __cri_close, __NR_close, int);
172:cri_syscall0(int, __cri_sched_yield, __NR_sched_yield)
173:cri_syscall2(int, __cri_nanosleep, __NR_nanosleep, const struct
timespec*, struct timespec*)
174:cri_syscall1(int, __cri_exit, __NR_exit, int)
It appears to be the result of a badly written macro. I attempted to
check for any missing or extra brackets but was unable to spot any.
Here is the code for cri_syscall3:
#define cri_syscall3(type,name,nr,arg1,arg2,arg3) \
type name(type1 arg1,type2 arg2,type3 arg3,int *errno_p) \
{ \
register long __o0 __asm__ ("o0") = (long)(arg1); \
register long __o1 __asm__ ("o1") = (long)(arg2); \
register long __o2 __asm__ ("o2") = (long)(arg3); \
register long __g1 __asm__ ("g1") = name; \
__asm __volatile (CRI_SYSCALL_STRING : \
"=r" (__g1), "=r" (__o0) : \
"0" (__g1), "1" (__o0), "r" (__o1), \
"r" (__o2) : \
_CRI_SYSCALL_CLOBBERS); \
cri_syscall_cleanup(__o0, errno_p); \
return (type)__o0; \
}
If you have some time, would you check whether this is written
correctly? Hopefully this is the last step of porting to sparc.
Thank you.
--
Vincentius Robby
Quoting "Paul H. Hargrove" <PHHargrove_at_lbl_dot_gov>:
> The syscall macros you wrote may have taken my suggestion too
> literally, or perhaps I was not as clear as I intended. I sometimes
> take for granted how much of the non-obvious stuff I already know.
>
> 1) The macros from glibc are gcc-specific "expression statements"
> (or something like that), which is why they are bracketed as ({ body
> }). Such an compound expression evaluates to its last statement,
> which is __o0 in the case of the glibc syscall macros.
>
> 2) BLCR needs a macro that expands to define entire function, with a
> returned value, not just an expression which evaluates to the
> desired value. So, we need to pass __o0 into the
> cri_syscall_cleanup() macro, and then return it.
>
> 3) BLCR want's to look at the value and if it is bigger than
> 0xFFFFF000 (or 0xFFFFFFFFFFFFF000 on 64-bit) put its negative into
> *errno_p (if non-NULL) and change the return value to -1. That is
> the purpose of cri_syscall_cleanup(). This differs just slightly
> from the normal kernel return ABI.
>
> 4) The "memory", "cc", "cx", "dx" stuff is x86-specific register
> clobbers which you should remove.
>
> 5) The "string" is supplied by one of the ALL_CAPS macros earlier in
> .../sparc/sysdep.h, which in turn use values that are defined in
> .../sparc/sparc32/sysdep.h or .../sparc/sparc64/sysdep.h (same files
> which provide the value for __SYSCALL_CLOBBERS. I believe you want
> "string" to be __INTERNAL_SYSCALL_STRING, being sure to get the
> correct 32-bit or 64-bit version. However, the
> __INTERNAL_SYSCALL_STRING appears to handle the errno-related stuff
> a little bit on its own, so we don't want to use it exactly. In
> fact, I think that we can discard attempts as being optimal and just
> strip the error handing out of __INTERNAL_SYSCALL_STRING and leave
> it all in cri_syscall_cleanup().
>
> So changes needed:
> a) remove the x86-specific asm() from cri_syscall_cleanup()
> b) remove lone "__o0;" line
> c) pass __o0 in place of __g1 to cri_syscall_cleanup()
> d) return __o0 (with an explicit cast to "type" to avoid gcc warnings)
> e) insert the proper value in place of "string" and __SYSCALL_CLOBBERS
>
> So, I think you want the following:
>
> #if (SIZEOF_VOID_P == 4)
> #define CRI_SYSCALL_CLOBBERS "g2", "g3", "g4", "g5", "g6", \
> "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", \
> "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", \
> "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23", \
> "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31", \
> "cc", "memory"
> #define CRI_SYSCALL_STRING "ta 0x10;"
> #elif (SIZEOF_VOID_P == 8)
> #define CRI_SYSCALL_CLOBBERS "g2", "g3", "g4", "g5", "g6", \
> "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", \
> "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", \
> "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23", \
> "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31", \
> "f32", "f34", "f36", "f38", "f40", "f42", "f44", "f46", \
> "f48", "f50", "f52", "f54", "f56", "f58", "f60", "f62", \
> "cc", "memory"
> #define CRI_SYSCALL_STRING "ta 0x6d;"
> #else
> #error "Unknown SIZEOF_VOID_P"
> #endif
>
> #define cri_syscall_cleanup(res,errno_p) \
> if ((unsigned long)res >= (unsigned long)(-4096)) { \
> if (errno_p != NULL) { *errno_p = -res; } \
> res = -1; \
> }
>
> #define cri_syscall0(type,name,nr) \
> type name(int *errno_p) \
> { \
> register long __o0 __asm__ ("o0"); \
> register long __g1 __asm__ ("g1") = name; \
> __asm __volatile (CRI_SYSCALL_STRING : \
> "=r" (__g1), "=r" (__o0) : \
> "0" (__g1) : \
> CRI_SYSCALL_CLOBBERS); \
> cri_syscall_cleanup(__o0, errno_p); \
> return (type)__o0; \
> }
>
> #define cri_syscall1(type,name,nr,arg1) \
> type name(type1 arg1,int *errno_p) \
> { \
> register long __o0 __asm__ ("o0") = (long)(arg1); \
> register long __g1 __asm__ ("g1") = name; \
> __asm __volatile (CRI_SYSCALL_STRING : \
> "=r" (__g1), "=r" (__o0) : \
> "0" (__g1), "1" (__o0) : \
> _CRI_SYSCALL_CLOBBERS); \
> cri_syscall_cleanup(__o0, errno_p); \
> return (type)__o0; \
> }
>
> Just to be 100% proper about this code I've included here:
> Signed-off-by: Paul H. Hargrove <PHHargrove_at_lbl_dot_gov>
>
> -Paul
>
>
> --
> Paul H. Hargrove PHHargrove_at_lbl_dot_gov
> Future Technologies Group HPC Research Department
> Tel: +1-510-495-2352
> Lawrence Berkeley National Laboratory Fax: +1-510-486-6900
>
>
>
>