From: Paul H. Hargrove (PHHargrove_at_lbl_dot_gov)
Date: Wed Sep 03 2008 - 13:31:04 PDT
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
Vincentius Robby wrote:
> Hello Paul,
>
> Apologies, regarding the directory I forgot to add the CR_ARCH32
> option because I was working on a 64-bit sparc machine for testing this.
> While my question regarding the fetch and add still stands, I am
> playing around with the syscall handlers now. Currently the errors I
> am encountering are:
> 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:172: error: expected string literal before
> 'string'
> ../../libcr/cr_syscall.c:172: warning: statement with no effect
> ../../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'
>
> and this is what the beginning of libcr/arch/sparc/cr_arch.h looks like:
> #define cri_syscall_cleanup(res,errno_p) \
> __asm__ volatile ("" ::: "memory", "cc", "cx", "dx");\
> 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 (string : "=r" (__g1), "=r" (__o0) : \
> "0" (__g1) : \
> __SYSCALL_CLOBBERS); \
> __o0; \
> cri_syscall_cleanup(__g1, errno_p); \
> }
>
> #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 (string : "=r" (__g1), "=r" (__o0) : \
> "0" (__g1), "1" (__o0) : \
> __SYSCALL_CLOBBERS); \
> __o0; \
> cri_syscall_cleanup(__g1, errno_p); \
> }
>
> One question I have is where it is written __asm __volatile (string :,
> is the string to be replaced by 'type'? Originally the inline_syscall
> has arguments (string,name) so I assumed I had to change the 'string'
> to 'type' in the __asm __volatile arguments but after these errors I
> changed it back, but either way it was not a solution to the errors.
> Is this what you mentioned for the inclusion syscall_cleanup routine
> as well?
>
> Thank you.
>
--
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