Patchwork [07/15] mips: Use Linux kABI for syscall return

login
register
mail settings
Submitter Adhemerval Zanella Netto
Date Feb. 10, 2020, 7:20 p.m.
Message ID <20200210192038.23588-7-adhemerval.zanella@linaro.org>
Download mbox | patch
Permalink /patch/37874/
State New
Headers show

Comments

Adhemerval Zanella Netto - Feb. 10, 2020, 7:20 p.m.
It changes the mips INTERNAL_SYSCALL* and internal_syscall*  macros
to return a negative value instead of 'a3' register value on 'err'
macro argument.

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 mips64-linux-gnu, mips64n32-linux-gnu, and mips-linux-gnu.
---
 sysdeps/unix/sysv/linux/mips/mips32/sysdep.h | 32 ++++++++------------
 sysdeps/unix/sysv/linux/mips/mips64/sysdep.h | 28 +++++++----------
 sysdeps/unix/sysv/linux/mips/sysdep.h        | 16 ----------
 3 files changed, 23 insertions(+), 53 deletions(-)

Patch

diff --git a/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h b/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h
index beefcf284b..6842ff5211 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h
+++ b/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h
@@ -61,13 +61,14 @@ 
      result_var; })
 
 #undef INTERNAL_SYSCALL_DECL
-#define INTERNAL_SYSCALL_DECL(err) long err __attribute__ ((unused))
+#define INTERNAL_SYSCALL_DECL(err) do { } while (0)
 
 #undef INTERNAL_SYSCALL_ERROR_P
-#define INTERNAL_SYSCALL_ERROR_P(val, err)   ((void) (val), (long) (err))
+#define INTERNAL_SYSCALL_ERROR_P(val, err) \
+  ((unsigned long) (val) >= (unsigned long) -4095)
 
 #undef INTERNAL_SYSCALL_ERRNO
-#define INTERNAL_SYSCALL_ERRNO(val, err)     ((void) (err), val)
+#define INTERNAL_SYSCALL_ERRNO(val, err)     (-(val))
 
 /* Note that the original Linux syscall restart convention required the
    instruction immediately preceding SYSCALL to initialize $v0 with the
@@ -128,7 +129,6 @@  union __mips_syscall_return
 ({									\
 	union __mips_syscall_return _sc_ret;				\
 	_sc_ret.val = __mips16_syscall##nr (args, number);		\
-	err = _sc_ret.reg.v1;						\
 	_sc_ret.reg.v0;							\
 })
 
@@ -167,8 +167,7 @@  union __mips_syscall_return
 	: "=r" (__v0), "=r" (__a3)					\
 	: input								\
 	: __SYSCALL_CLOBBERS);						\
-	err = __a3;							\
-	_sys_result = __v0;						\
+	_sys_result = __a3 != 0 ? -__v0 : __v0;				\
 	}								\
 	_sys_result;							\
 })
@@ -191,8 +190,7 @@  union __mips_syscall_return
 	: "=r" (__v0), "=r" (__a3)					\
 	: input, "r" (__a0)						\
 	: __SYSCALL_CLOBBERS);						\
-	err = __a3;							\
-	_sys_result = __v0;						\
+	_sys_result = __a3 != 0 ? -__v0 : __v0;				\
 	}								\
 	_sys_result;							\
 })
@@ -216,8 +214,7 @@  union __mips_syscall_return
 	: "=r" (__v0), "=r" (__a3)					\
 	: input, "r" (__a0), "r" (__a1)					\
 	: __SYSCALL_CLOBBERS);						\
-	err = __a3;							\
-	_sys_result = __v0;						\
+	_sys_result = __a3 != 0 ? -__v0 : __v0;				\
 	}								\
 	_sys_result;							\
 })
@@ -243,8 +240,7 @@  union __mips_syscall_return
 	: "=r" (__v0), "=r" (__a3)					\
 	: input, "r" (__a0), "r" (__a1), "r" (__a2)			\
 	: __SYSCALL_CLOBBERS);						\
-	err = __a3;							\
-	_sys_result = __v0;						\
+	_sys_result = __a3 != 0 ? -__v0 : __v0;				\
 	}								\
 	_sys_result;							\
 })
@@ -270,8 +266,7 @@  union __mips_syscall_return
 	: "=r" (__v0), "+r" (__a3)					\
 	: input, "r" (__a0), "r" (__a1), "r" (__a2)			\
 	: __SYSCALL_CLOBBERS);						\
-	err = __a3;							\
-	_sys_result = __v0;						\
+	_sys_result = __a3 != 0 ? -__v0 : __v0;				\
 	}								\
 	_sys_result;							\
 })
@@ -300,8 +295,7 @@  libc_hidden_proto (__mips_syscall5, nomips16)
 				       (long) (arg4),			\
 				       (long) (arg5),			\
 				       (long) (number));		\
-	err = _sc_ret.reg.v1;						\
-	_sc_ret.reg.v0;							\
+	_sc_ret.reg.v1 != 0 ? -_sc_ret.reg.v0 : _sc_ret.reg.v0;		\
 })
 
 long long __nomips16 __mips_syscall6 (long arg1, long arg2, long arg3,
@@ -320,8 +314,7 @@  libc_hidden_proto (__mips_syscall6, nomips16)
 				       (long) (arg5),			\
 				       (long) (arg6),			\
 				       (long) (number));		\
-	err = _sc_ret.reg.v1;						\
-	_sc_ret.reg.v0;							\
+	_sc_ret.reg.v1 != 0 ? -_sc_ret.reg.v0 : _sc_ret.reg.v0;		\
 })
 
 long long __nomips16 __mips_syscall7 (long arg1, long arg2, long arg3,
@@ -342,8 +335,7 @@  libc_hidden_proto (__mips_syscall7, nomips16)
 				       (long) (arg6),			\
 				       (long) (arg7),			\
 				       (long) (number));		\
-	err = _sc_ret.reg.v1;						\
-	_sc_ret.reg.v0;							\
+	_sc_ret.reg.v1 != 0 ? -_sc_ret.reg.v0 : _sc_ret.reg.v0;		\
 })
 
 #if __mips_isa_rev >= 6
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/sysdep.h b/sysdeps/unix/sysv/linux/mips/mips64/sysdep.h
index 617e229a67..072016f07e 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/mips/mips64/sysdep.h
@@ -69,13 +69,14 @@  typedef long int __syscall_arg_t;
      result_var; })
 
 #undef INTERNAL_SYSCALL_DECL
-#define INTERNAL_SYSCALL_DECL(err) long err __attribute__ ((unused))
+#define INTERNAL_SYSCALL_DECL(err) do { } while (0)
 
 #undef INTERNAL_SYSCALL_ERROR_P
-#define INTERNAL_SYSCALL_ERROR_P(val, err)   ((void) (val), (long) (err))
+#define INTERNAL_SYSCALL_ERROR_P(val, err) \
+  ((unsigned long) (val) >= (unsigned long) -4095)
 
 #undef INTERNAL_SYSCALL_ERRNO
-#define INTERNAL_SYSCALL_ERRNO(val, err)     ((void) (err), val)
+#define INTERNAL_SYSCALL_ERRNO(val, err)     (-(val))
 
 /* Note that the original Linux syscall restart convention required the
    instruction immediately preceding SYSCALL to initialize $v0 with the
@@ -133,8 +134,7 @@  typedef long int __syscall_arg_t;
 	: "=r" (__v0), "=r" (__a3)					\
 	: input								\
 	: __SYSCALL_CLOBBERS);						\
-	err = __a3;							\
-	_sys_result = __v0;						\
+	_sys_result = __a3 != 0 ? -__v0 : __v0;				\
 	}								\
 	_sys_result;							\
 })
@@ -157,8 +157,7 @@  typedef long int __syscall_arg_t;
 	: "=r" (__v0), "=r" (__a3)					\
 	: input, "r" (__a0)						\
 	: __SYSCALL_CLOBBERS);						\
-	err = __a3;							\
-	_sys_result = __v0;						\
+	_sys_result = __a3 != 0 ? -__v0 : __v0;				\
 	}								\
 	_sys_result;							\
 })
@@ -182,8 +181,7 @@  typedef long int __syscall_arg_t;
 	: "=r" (__v0), "=r" (__a3)					\
 	: input, "r" (__a0), "r" (__a1)					\
 	: __SYSCALL_CLOBBERS);						\
-	err = __a3;							\
-	_sys_result = __v0;						\
+	_sys_result = __a3 != 0 ? -__v0 : __v0;				\
 	}								\
 	_sys_result;							\
 })
@@ -209,8 +207,7 @@  typedef long int __syscall_arg_t;
 	: "=r" (__v0), "=r" (__a3)					\
 	: input, "r" (__a0), "r" (__a1), "r" (__a2)			\
 	: __SYSCALL_CLOBBERS);						\
-	err = __a3;							\
-	_sys_result = __v0;						\
+	_sys_result = __a3 != 0 ? -__v0 : __v0;				\
 	}								\
 	_sys_result;							\
 })
@@ -236,8 +233,7 @@  typedef long int __syscall_arg_t;
 	: "=r" (__v0), "+r" (__a3)					\
 	: input, "r" (__a0), "r" (__a1), "r" (__a2)			\
 	: __SYSCALL_CLOBBERS);						\
-	err = __a3;							\
-	_sys_result = __v0;						\
+	_sys_result = __a3 != 0 ? -__v0 : __v0;				\
 	}								\
 	_sys_result;							\
 })
@@ -264,8 +260,7 @@  typedef long int __syscall_arg_t;
 	: "=r" (__v0), "+r" (__a3)					\
 	: input, "r" (__a0), "r" (__a1), "r" (__a2), "r" (__a4)		\
 	: __SYSCALL_CLOBBERS);						\
-	err = __a3;							\
-	_sys_result = __v0;						\
+	_sys_result = __a3 != 0 ? -__v0 : __v0;				\
 	}								\
 	_sys_result;							\
 })
@@ -294,8 +289,7 @@  typedef long int __syscall_arg_t;
 	: input, "r" (__a0), "r" (__a1), "r" (__a2), "r" (__a4),	\
 	  "r" (__a5)							\
 	: __SYSCALL_CLOBBERS);						\
-	err = __a3;							\
-	_sys_result = __v0;						\
+	_sys_result = __a3 != 0 ? -__v0 : __v0;				\
 	}								\
 	_sys_result;							\
 })
diff --git a/sysdeps/unix/sysv/linux/mips/sysdep.h b/sysdeps/unix/sysv/linux/mips/sysdep.h
index cdfc0b1b58..877768a249 100644
--- a/sysdeps/unix/sysv/linux/mips/sysdep.h
+++ b/sysdeps/unix/sysv/linux/mips/sysdep.h
@@ -28,19 +28,3 @@ 
 #endif
 #define HAVE_GETTIMEOFDAY_VSYSCALL      "__vdso_gettimeofday"
 #define HAVE_CLOCK_GETRES_VSYSCALL      "__vdso_clock_getres"
-
-#ifndef __ASSEMBLER__
-
-/* Standard MIPS syscalls have an error flag, and return a positive errno
-   when the error flag is set. Emulate this behaviour for vsyscalls so that
-   the INTERNAL_SYSCALL_{ERROR_P,ERRNO} macros work correctly.  */
-#define INTERNAL_VSYSCALL_CALL(funcptr, err, nr, args...)		\
-  ({									\
-    long _ret = funcptr (args);						\
-    err = ((unsigned long) (_ret) >= (unsigned long) -4095L);		\
-    if (err)								\
-      _ret = -_ret;							\
-    _ret;								\
-  })
-
-#endif /* __ASSEMBLER__  */