[Qemu-devel] [PATCH v3 15/19] linux-user: Split out pread64, pwrite64

[Richard Henderson]

Signed-off-by: Richard Henderson <address@hidden>
---
 linux-user/syscall.h           | 44 +++++++++++++++++++++
 linux-user/syscall.c           | 70 ----------------------------------
 linux-user/syscall_file.c      | 61 +++++++++++++++++++++++++++--
 linux-user/gen_syscall_list.py |  2 +
 linux-user/strace.list         |  6 ---
 5 files changed, 104 insertions(+), 79 deletions(-)

diff --git a/linux-user/syscall.h b/linux-user/syscall.h
index 3fc49d5b65..a157e25bba 100644
--- a/linux-user/syscall.h
+++ b/linux-user/syscall.h
@@ -174,6 +174,50 @@ struct iovec *lock_iovec(int type, abi_ulong target_addr,
 void unlock_iovec(struct iovec *vec, abi_ulong target_addr,
                   abi_ulong count, int copy);
 
+/* Returns true if syscall NUM expects 64bit types aligned even
+ * on pairs of registers.
+ */
+static inline bool regpairs_aligned(void *cpu_env, int num)
+{
+#ifdef TARGET_ARM
+    return ((CPUARMState *)cpu_env)->eabi;
+#elif defined(TARGET_MIPS) && TARGET_ABI_BITS == 32
+    return true;
+#elif defined(TARGET_PPC) && !defined(TARGET_PPC64)
+    /* SysV AVI for PPC32 expects 64bit parameters to be passed on
+     * odd/even pairs of registers which translates to the same as
+     * we start with r3 as arg1
+     */
+    return true;
+#elif defined(TARGET_SH4)
+    /* SH4 doesn't align register pairs, except for p{read,write}64 */
+    switch (num) {
+    case TARGET_NR_pread64:
+    case TARGET_NR_pwrite64:
+        return true;
+    default:
+        return false;
+    }
+#elif defined(TARGET_XTENSA)
+    return true;
+#else
+    return false;
+#endif
+}
+
+static inline uint64_t target_offset64(abi_ulong word0, abi_ulong word1)
+{
+#if TARGET_ABI_BITS == 32
+# ifdef TARGET_WORDS_BIGENDIAN
+    return ((uint64_t)word0 << 32) | word1;
+# else
+    return ((uint64_t)word1 << 32) | word0;
+# endif
+#else
+    return word0;
+#endif
+}
+
 /* Temporary declarations from syscall_foo.c back to main syscall.c.
  * These indicate incomplete conversion.
  */
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 381ee9c3a2..cdc9787240 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -642,38 +642,6 @@ static inline int next_free_host_timer(void)
 }
 #endif
 
-/* ARM EABI and MIPS expect 64bit types aligned even on pairs or registers */
-#ifdef TARGET_ARM
-static inline int regpairs_aligned(void *cpu_env, int num)
-{
-    return ((((CPUARMState *)cpu_env)->eabi) == 1) ;
-}
-#elif defined(TARGET_MIPS) && (TARGET_ABI_BITS == 32)
-static inline int regpairs_aligned(void *cpu_env, int num) { return 1; }
-#elif defined(TARGET_PPC) && !defined(TARGET_PPC64)
-/* SysV AVI for PPC32 expects 64bit parameters to be passed on odd/even pairs
- * of registers which translates to the same as ARM/MIPS, because we start with
- * r3 as arg1 */
-static inline int regpairs_aligned(void *cpu_env, int num) { return 1; }
-#elif defined(TARGET_SH4)
-/* SH4 doesn't align register pairs, except for p{read,write}64 */
-static inline int regpairs_aligned(void *cpu_env, int num)
-{
-    switch (num) {
-    case TARGET_NR_pread64:
-    case TARGET_NR_pwrite64:
-        return 1;
-
-    default:
-        return 0;
-    }
-}
-#elif defined(TARGET_XTENSA)
-static inline int regpairs_aligned(void *cpu_env, int num) { return 1; }
-#else
-static inline int regpairs_aligned(void *cpu_env, int num) { return 0; }
-#endif
-
 #define ERRNO_TABLE_SIZE 1200
 
 /* target_to_host_errno_table[] is initialized from
@@ -6864,22 +6832,6 @@ void syscall_init(void)
     }
 }
 
-#if TARGET_ABI_BITS == 32
-static inline uint64_t target_offset64(uint32_t word0, uint32_t word1)
-{
-#ifdef TARGET_WORDS_BIGENDIAN
-    return ((uint64_t)word0 << 32) | word1;
-#else
-    return ((uint64_t)word1 << 32) | word0;
-#endif
-}
-#else /* TARGET_ABI_BITS == 32 */
-static inline uint64_t target_offset64(uint64_t word0, uint64_t word1)
-{
-    return word0;
-}
-#endif /* TARGET_ABI_BITS != 32 */
-
 #ifdef TARGET_NR_truncate64
 static inline abi_long target_truncate64(void *cpu_env, const char *arg1,
                                          abi_long arg2,
@@ -10078,28 +10030,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
abi_long arg1,
 #else
 #error unreachable
 #endif
-#endif
-#ifdef TARGET_NR_pread64
-    case TARGET_NR_pread64:
-        if (regpairs_aligned(cpu_env, num)) {
-            arg4 = arg5;
-            arg5 = arg6;
-        }
-        if (!(p = lock_user(VERIFY_WRITE, arg2, arg3, 0)))
-            return -TARGET_EFAULT;
-        ret = get_errno(pread64(arg1, p, arg3, target_offset64(arg4, arg5)));
-        unlock_user(p, arg2, ret);
-        return ret;
-    case TARGET_NR_pwrite64:
-        if (regpairs_aligned(cpu_env, num)) {
-            arg4 = arg5;
-            arg5 = arg6;
-        }
-        if (!(p = lock_user(VERIFY_READ, arg2, arg3, 1)))
-            return -TARGET_EFAULT;
-        ret = get_errno(pwrite64(arg1, p, arg3, target_offset64(arg4, arg5)));
-        unlock_user(p, arg2, 0);
-        return ret;
 #endif
     case TARGET_NR_getcwd:
         if (!(p = lock_user(VERIFY_WRITE, arg1, arg2, 0)))
diff --git a/linux-user/syscall_file.c b/linux-user/syscall_file.c
index 4cc7051847..aae9c49599 100644
--- a/linux-user/syscall_file.c
+++ b/linux-user/syscall_file.c
@@ -378,15 +378,70 @@ SYSCALL_IMPL(openat)
 }
 SYSCALL_DEF(openat, ARG_ATDIRFD, ARG_STR, ARG_OPENFLAG, ARG_MODEFLAG);
 
+/* Both pread64 and pwrite64 merge args into a 64-bit offset,
+ * but the input registers and ordering are target specific.
+ */
+#if TARGET_ABI_BITS == 32
+SYSCALL_ARGS(pread64_pwrite64)
+{
+    /* We have already assigned out[0-2].  */
+    int off = regpairs_aligned(cpu_env, TARGET_NR_pread64);
+    out[3] = target_offset64(in[3 + off], in[4 + off]);
+    return def;
+}
+#else
+#define args_pread64_pwrite64 NULL
+#endif
+
+SYSCALL_IMPL(pread64)
+{
+    void *p = lock_user(VERIFY_WRITE, arg2, arg3, 0);
+    abi_long ret;
+
+    if (!p) {
+        return -TARGET_EFAULT;
+    }
+    ret = get_errno(pread64(arg1, p, arg3, arg4));
+    unlock_user(p, arg2, ret);
+    return ret;
+}
+
+const SyscallDef def_pread64 = {
+    .name = "pread64",
+    .args = args_pread64_pwrite64,
+    .impl = impl_pread64,
+    .arg_type = { ARG_DEC, ARG_PTR, ARG_DEC, ARG_DEC64 }
+};
+
+SYSCALL_IMPL(pwrite64)
+{
+    void *p = lock_user(VERIFY_READ, arg2, arg3, 0);
+    abi_long ret;
+
+    if (!p) {
+        return -TARGET_EFAULT;
+    }
+    ret = get_errno(pwrite64(arg1, p, arg3, arg4));
+    unlock_user(p, arg2, 0);
+    return ret;
+}
+
+const SyscallDef def_pwrite64 = {
+    .name = "pwrite64",
+    .args = args_pread64_pwrite64,
+    .impl = impl_pwrite64,
+    .arg_type = { ARG_DEC, ARG_PTR, ARG_DEC, ARG_DEC64 }
+};
+
 /* Both preadv and pwritev merge args 4/5 into a 64-bit offset.
  * Moreover, the parts are *always* in little-endian order.
  */
 #if TARGET_ABI_BITS == 32
 SYSCALL_ARGS(preadv_pwritev)
 {
-    /* We have already assigned out[0-3].  */
-    abi_ulong lo = in[4], hi = in[5];
-    out[4] = ((hi << (TARGET_ABI_BITS - 1)) << 1) | lo;
+    /* We have already assigned out[0-2].  */
+    abi_ulong lo = in[3], hi = in[4];
+    out[3] = ((hi << (TARGET_ABI_BITS - 1)) << 1) | lo;
     return def;
 }
 #else
diff --git a/linux-user/gen_syscall_list.py b/linux-user/gen_syscall_list.py
index ce6dca742c..7481d030ee 100644
--- a/linux-user/gen_syscall_list.py
+++ b/linux-user/gen_syscall_list.py
@@ -27,7 +27,9 @@ import sys
 unconditional_syscalls = [
     "close",
     "openat",
+    "pread64",
     "preadv",
+    "pwrite64",
     "pwritev",
     "read",
     "readv",
diff --git a/linux-user/strace.list b/linux-user/strace.list
index d5ee55ac82..d978cefa31 100644
--- a/linux-user/strace.list
+++ b/linux-user/strace.list
@@ -1025,9 +1025,6 @@
 #ifdef TARGET_NR_prctl
 { TARGET_NR_prctl, "prctl" , NULL, NULL, NULL },
 #endif
-#ifdef TARGET_NR_pread64
-{ TARGET_NR_pread64, "pread64" , NULL, NULL, NULL },
-#endif
 #ifdef TARGET_NR_prlimit64
 { TARGET_NR_prlimit64, "prlimit64" , NULL, NULL, NULL },
 #endif
@@ -1052,9 +1049,6 @@
 #ifdef TARGET_NR_putpmsg
 { TARGET_NR_putpmsg, "putpmsg" , NULL, NULL, NULL },
 #endif
-#ifdef TARGET_NR_pwrite64
-{ TARGET_NR_pwrite64, "pwrite64" , NULL, NULL, NULL },
-#endif
 #ifdef TARGET_NR_query_module
 { TARGET_NR_query_module, "query_module" , NULL, NULL, NULL },
 #endif
-- 
2.17.1