[PATCH 03/15] sparc: Use Linux kABI for syscall return
Adhemerval Zanella
adhemerval.zanella@linaro.org
Tue Feb 11 18:55:00 GMT 2020
On 11/02/2020 08:15, Florian Weimer wrote:
> * Adhemerval Zanella:
>
>> + if (__glibc_unlikely (__g1 != 0)) \
>
> This change is inconsistent with the other updates, which use __g1 ==
> -1. Is this deliberate?
>
> Thanks,
> Florian
>
In fact __SYSCALL_STRING already sets the 'o0' to a negative value if
the 'xcc' condition is set (indicating that the syscall has failed).
The 'g1' check is superfluous, it will be always true since 'g1' will
be either 0 or 1.
And both the set and check of 'g1' result is also superfluous, since 'o0'
will already hold all the required information.
Below is an updated patch, checked on sparc64-linux-gnu and
sparcv9-linux-gnu.
--
It changes the sparc internal_syscall* macros to return a negative
value instead the 'g1' register value on 'err' macro argument.
The __SYSCALL_STRING macro is also changed to no set the 'g1'
value, since 'o1' already holds all the required information
to check if syscall has failed.
The macro INTERNAL_SYSCALL_DECL is no longer required, and the
INTERNAL_SYSCALL_ERROR_P follows the other Linux kABIS. The
redefinition of INTERNAL_VSYSCALL_CALL is also no longer
required.
Checked on sparc64-linux-gnu and sparcv9-linux-gnu. It fixes
the sporadic issues on sparc32 where clock_nanosleep does not
act as cancellation entrypoint.
---
.../unix/sysv/linux/sparc/sparc32/sysdep.h | 3 +-
.../unix/sysv/linux/sparc/sparc64/sysdep.h | 3 +-
sysdeps/unix/sysv/linux/sparc/sysdep.h | 80 +++++++++----------
3 files changed, 38 insertions(+), 48 deletions(-)
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/sysdep.h b/sysdeps/unix/sysv/linux/sparc/sparc32/sysdep.h
index 8461261674..2c3754770b 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/sysdep.h
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/sysdep.h
@@ -110,9 +110,8 @@ ENTRY(name); \
#define __SYSCALL_STRING \
"ta 0x10;" \
"bcc 1f;" \
- " mov 0, %%g1;" \
+ " nop;" \
"sub %%g0, %%o0, %%o0;" \
- "mov 1, %%g1;" \
"1:"
#define __SYSCALL_CLOBBERS \
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/sysdep.h b/sysdeps/unix/sysv/linux/sparc/sparc64/sysdep.h
index b9a4c75cbd..2010faf50f 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/sysdep.h
@@ -109,9 +109,8 @@ ENTRY(name); \
#define __SYSCALL_STRING \
"ta 0x6d;" \
"bcc,pt %%xcc, 1f;" \
- " mov 0, %%g1;" \
+ " nop;" \
"sub %%g0, %%o0, %%o0;" \
- "mov 1, %%g1;" \
"1:"
#define __SYSCALL_CLOBBERS \
diff --git a/sysdeps/unix/sysv/linux/sparc/sysdep.h b/sysdeps/unix/sysv/linux/sparc/sysdep.h
index 0c32780d9c..a0dfdbe079 100644
--- a/sysdeps/unix/sysv/linux/sparc/sysdep.h
+++ b/sysdeps/unix/sysv/linux/sparc/sysdep.h
@@ -34,13 +34,6 @@
#else /* __ASSEMBLER__ */
-#define INTERNAL_VSYSCALL_CALL(funcptr, err, nr, args...) \
- ({ \
- long _ret = funcptr (args); \
- err = ((unsigned long) (_ret) >= (unsigned long) -4095L); \
- _ret; \
- })
-
# define VDSO_NAME "LINUX_2.6"
# define VDSO_HASH 61765110
@@ -65,108 +58,107 @@
})
#undef INTERNAL_SYSCALL_DECL
-#define INTERNAL_SYSCALL_DECL(err) \
- register long err __asm__("g1");
+#define INTERNAL_SYSCALL_DECL(err) do { } while (0)
#undef INTERNAL_SYSCALL
#define INTERNAL_SYSCALL(name, err, nr, args...) \
- inline_syscall##nr(__SYSCALL_STRING, err, __NR_##name, args)
+ internal_syscall##nr(__SYSCALL_STRING, err, __NR_##name, args)
#undef INTERNAL_SYSCALL_NCS
#define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \
- inline_syscall##nr(__SYSCALL_STRING, err, name, args)
+ internal_syscall##nr(__SYSCALL_STRING, err, name, args)
#undef INTERNAL_SYSCALL_ERROR_P
#define INTERNAL_SYSCALL_ERROR_P(val, err) \
- ((void) (val), __builtin_expect((err) != 0, 0))
+ ((unsigned long) (val) > -4096UL)
#undef INTERNAL_SYSCALL_ERRNO
#define INTERNAL_SYSCALL_ERRNO(val, err) (-(val))
-#define inline_syscall0(string,err,name,dummy...) \
+#define internal_syscall0(string,err,name,dummy...) \
({ \
+ register long int __g1 __asm__ ("g1") = (name); \
register long __o0 __asm__ ("o0"); \
- err = name; \
- __asm __volatile (string : "=r" (err), "=r" (__o0) : \
- "0" (err) : \
+ __asm __volatile (string : "=r" (__o0) : \
+ "0" (__g1) : \
__SYSCALL_CLOBBERS); \
__o0; \
})
-#define inline_syscall1(string,err,name,arg1) \
+#define internal_syscall1(string,err,name,arg1) \
({ \
+ register long int __g1 __asm__("g1") = (name); \
register long __o0 __asm__ ("o0") = (long)(arg1); \
- err = name; \
- __asm __volatile (string : "=r" (err), "=r" (__o0) : \
- "0" (err), "1" (__o0) : \
+ __asm __volatile (string : "=r" (__o0) : \
+ "r" (__g1), "0" (__o0) : \
__SYSCALL_CLOBBERS); \
__o0; \
})
-#define inline_syscall2(string,err,name,arg1,arg2) \
+#define internal_syscall2(string,err,name,arg1,arg2) \
({ \
+ register long int __g1 __asm__("g1") = (name); \
register long __o0 __asm__ ("o0") = (long)(arg1); \
register long __o1 __asm__ ("o1") = (long)(arg2); \
- err = name; \
- __asm __volatile (string : "=r" (err), "=r" (__o0) : \
- "0" (err), "1" (__o0), "r" (__o1) : \
+ __asm __volatile (string : "=r" (__o0) : \
+ "r" (__g1), "0" (__o0), "r" (__o1) : \
__SYSCALL_CLOBBERS); \
__o0; \
})
-#define inline_syscall3(string,err,name,arg1,arg2,arg3) \
+#define internal_syscall3(string,err,name,arg1,arg2,arg3) \
({ \
+ register long int __g1 __asm__("g1") = (name); \
register long __o0 __asm__ ("o0") = (long)(arg1); \
register long __o1 __asm__ ("o1") = (long)(arg2); \
register long __o2 __asm__ ("o2") = (long)(arg3); \
- err = name; \
- __asm __volatile (string : "=r" (err), "=r" (__o0) : \
- "0" (err), "1" (__o0), "r" (__o1), \
+ __asm __volatile (string : "=r" (__o0) : \
+ "r" (__g1), "0" (__o0), "r" (__o1), \
"r" (__o2) : \
__SYSCALL_CLOBBERS); \
__o0; \
})
-#define inline_syscall4(string,err,name,arg1,arg2,arg3,arg4) \
+#define internal_syscall4(string,err,name,arg1,arg2,arg3,arg4) \
({ \
+ register long int __g1 __asm__("g1") = (name); \
register long __o0 __asm__ ("o0") = (long)(arg1); \
register long __o1 __asm__ ("o1") = (long)(arg2); \
register long __o2 __asm__ ("o2") = (long)(arg3); \
register long __o3 __asm__ ("o3") = (long)(arg4); \
- err = name; \
- __asm __volatile (string : "=r" (err), "=r" (__o0) : \
- "0" (err), "1" (__o0), "r" (__o1), \
+ __asm __volatile (string : "=r" (__o0) : \
+ "r" (__g1), "0" (__o0), "r" (__o1), \
"r" (__o2), "r" (__o3) : \
__SYSCALL_CLOBBERS); \
__o0; \
})
-#define inline_syscall5(string,err,name,arg1,arg2,arg3,arg4,arg5) \
+#define internal_syscall5(string,err,name,arg1,arg2,arg3,arg4,arg5) \
({ \
+ register long int __g1 __asm__("g1") = (name); \
register long __o0 __asm__ ("o0") = (long)(arg1); \
register long __o1 __asm__ ("o1") = (long)(arg2); \
register long __o2 __asm__ ("o2") = (long)(arg3); \
register long __o3 __asm__ ("o3") = (long)(arg4); \
register long __o4 __asm__ ("o4") = (long)(arg5); \
- err = name; \
- __asm __volatile (string : "=r" (err), "=r" (__o0) : \
- "0" (err), "1" (__o0), "r" (__o1), \
+ __asm __volatile (string : "=r" (__o0) : \
+ "r" (__g1), "0" (__o0), "r" (__o1), \
"r" (__o2), "r" (__o3), "r" (__o4) : \
__SYSCALL_CLOBBERS); \
__o0; \
})
-#define inline_syscall6(string,err,name,arg1,arg2,arg3,arg4,arg5,arg6) \
+#define internal_syscall6(string,err,name,arg1,arg2,arg3,arg4,arg5,arg6)\
({ \
+ register long int __g1 __asm__("g1") = (name); \
register long __o0 __asm__ ("o0") = (long)(arg1); \
register long __o1 __asm__ ("o1") = (long)(arg2); \
register long __o2 __asm__ ("o2") = (long)(arg3); \
register long __o3 __asm__ ("o3") = (long)(arg4); \
register long __o4 __asm__ ("o4") = (long)(arg5); \
register long __o5 __asm__ ("o5") = (long)(arg6); \
- err = name; \
- __asm __volatile (string : "=r" (err), "=r" (__o0) : \
- "0" (err), "1" (__o0), "r" (__o1), \
+ __asm __volatile (string : "=r" (__o0) : \
+ "r" (__g1), "0" (__o0), "r" (__o1), \
"r" (__o2), "r" (__o3), "r" (__o4), \
"r" (__o5) : \
__SYSCALL_CLOBBERS); \
@@ -182,13 +174,13 @@
register long __o4 __asm__ ("o4") = (long)(arg5); \
register long __g1 __asm__ ("g1") = __NR_clone; \
__asm __volatile (__SYSCALL_STRING : \
- "=r" (__g1), "=r" (__o0), "=r" (__o1) : \
- "0" (__g1), "1" (__o0), "2" (__o1), \
+ "=r" (__o0), "=r" (__o1) : \
+ "r" (__g1), "0" (__o0), "1" (__o1), \
"r" (__o2), "r" (__o3), "r" (__o4) : \
__SYSCALL_CLOBBERS); \
- if (INTERNAL_SYSCALL_ERROR_P (__o0, __g1)) \
+ if (__glibc_unlikely ((unsigned long int) (__o0) > -4096UL)) \
{ \
- __set_errno (INTERNAL_SYSCALL_ERRNO (__o0, __g1)); \
+ __set_errno (-__o0); \
__o0 = -1L; \
} \
else \
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