While adding MIPS support to breakpad I came across a few problems with the
current version of lss support:
* LSS_ERRNO may involve a function call so LSS_RETURN must preserve $v0 value
* syscall clobbers $25/t9
* __v0 needs "+r" constraint when it contains the system call number
* Simplified and made consistent the O32 versions of syscall5/syscall6
* __r7 needs "+r" constraint in clone syscall
* __r7/__v1 need "+r" constraint in pipe syscall
AUTHOR=chris.jw.dearman
Review URL: https://chromiumcodereview.appspot.com/10067027
git-svn-id: http://linux-syscall-support.googlecode.com/svn/trunk/lss@10 829466d3-f3f5-3ae4-62ad-de35cf9bba21
diff --git a/linux_syscall_support.h b/linux_syscall_support.h
index 24b405d..7b7e59c 100644
--- a/linux_syscall_support.h
+++ b/linux_syscall_support.h
@@ -1424,7 +1424,8 @@
#define LSS_RETURN(type, res, err) \
do { \
if (err) { \
- LSS_ERRNO = (res); \
+ unsigned long __errnovalue = (res); \
+ LSS_ERRNO = __errnovalue; \
res = -1; \
} \
return (type) (res); \
@@ -2213,10 +2214,11 @@
#define LSS_BODY(type,name,r7,...) \
register unsigned long __v0 __asm__("$2") = __NR_##name; \
__asm__ __volatile__ ("syscall\n" \
- : "=&r"(__v0), r7 (__r7) \
+ : "+r"(__v0), r7 (__r7) \
: "0"(__v0), ##__VA_ARGS__ \
: "$8", "$9", "$10", "$11", "$12", \
- "$13", "$14", "$15", "$24", "memory"); \
+ "$13", "$14", "$15", "$24", "$25", \
+ "memory"); \
LSS_RETURN(type, __v0, __r7)
#undef _syscall0
#define _syscall0(type, name) \
@@ -2262,20 +2264,19 @@
type5 arg5) { \
LSS_REG(4, arg1); LSS_REG(5, arg2); LSS_REG(6, arg3); \
LSS_REG(7, arg4); \
- register unsigned long __v0 __asm__("$2"); \
+ register unsigned long __v0 __asm__("$2") = __NR_##name; \
__asm__ __volatile__ (".set noreorder\n" \
- "lw $2, %6\n" \
"subu $29, 32\n" \
- "sw $2, 16($29)\n" \
- "li $2, %2\n" \
+ "sw %5, 16($29)\n" \
"syscall\n" \
"addiu $29, 32\n" \
".set reorder\n" \
- : "=&r"(__v0), "+r" (__r7) \
- : "i" (__NR_##name), "r"(__r4), "r"(__r5), \
- "r"(__r6), "m" ((unsigned long)arg5) \
+ : "+r"(__v0), "+r" (__r7) \
+ : "r"(__r4), "r"(__r5), \
+ "r"(__r6), "r" ((unsigned long)arg5) \
: "$8", "$9", "$10", "$11", "$12", \
- "$13", "$14", "$15", "$24", "memory"); \
+ "$13", "$14", "$15", "$24", "$25", \
+ "memory"); \
LSS_RETURN(type, __v0, __r7); \
}
#else
@@ -2300,23 +2301,21 @@
type5 arg5, type6 arg6) { \
LSS_REG(4, arg1); LSS_REG(5, arg2); LSS_REG(6, arg3); \
LSS_REG(7, arg4); \
- register unsigned long __v0 __asm__("$2"); \
+ register unsigned long __v0 __asm__("$2") = __NR_##name; \
__asm__ __volatile__ (".set noreorder\n" \
- "lw $2, %6\n" \
- "lw $8, %7\n" \
"subu $29, 32\n" \
- "sw $2, 16($29)\n" \
- "sw $8, 20($29)\n" \
- "li $2, %2\n" \
+ "sw %5, 16($29)\n" \
+ "sw %6, 20($29)\n" \
"syscall\n" \
"addiu $29, 32\n" \
".set reorder\n" \
- : "=&r"(__v0), "+r" (__r7) \
- : "i" (__NR_##name), "r"(__r4), "r"(__r5), \
+ : "+r"(__v0), "+r" (__r7) \
+ : "r"(__r4), "r"(__r5), \
"r"(__r6), "r" ((unsigned long)arg5), \
"r" ((unsigned long)arg6) \
: "$8", "$9", "$10", "$11", "$12", \
- "$13", "$14", "$15", "$24", "memory"); \
+ "$13", "$14", "$15", "$24", "$25", \
+ "memory"); \
LSS_RETURN(type, __v0, __r7); \
}
#else
@@ -2416,12 +2415,12 @@
#else
"daddu $29,16\n"
#endif
- : "=&r" (__v0), "=r" (__r7)
+ : "=&r" (__v0), "+r" (__r7)
: "i"(-EINVAL), "i"(__NR_clone), "i"(__NR_exit),
"r"(fn), "r"(__stack), "r"(__flags), "r"(arg),
"r"(__ptid), "r"(__r7), "r"(__ctid)
: "$9", "$10", "$11", "$12", "$13", "$14", "$15",
- "$24", "memory");
+ "$24", "$25", "memory");
}
LSS_RETURN(int, __v0, __r7);
}
@@ -3339,12 +3338,13 @@
register unsigned long __v1 __asm__("$3");
register unsigned long __r7 __asm__("$7");
__asm__ __volatile__ ("syscall\n"
- : "=&r"(__v0), "=&r"(__v1), "+r" (__r7)
+ : "+r"(__v0), "=r"(__v1), "=r" (__r7)
: "0"(__v0)
: "$8", "$9", "$10", "$11", "$12",
- "$13", "$14", "$15", "$24", "memory");
+ "$13", "$14", "$15", "$24", "$25", "memory");
if (__r7) {
- LSS_ERRNO = __v0;
+ unsigned long __errnovalue = __v0;
+ LSS_ERRNO = __errnovalue;
return -1;
} else {
p[0] = __v0;
