Commit a6fb6dcfc96ad63f9a21110165728da0b8311660 | zig

author	LemonBoy <thatlemon@gmail.com> 2020-03-03 17:19:40+01:00
committer	Andrew Kelley <andrew@ziglang.org> 2020-03-03 11:59:16-05:00
log	a6fb6dcfc96ad63f9a21110165728da0b8311660
tree	e45d24811bdcb06dfb258c1f59f074b2a8bf21d5
parent	226b801830857a9075fdd8180739105bb73eed0e

linux: Correct pread64 syscall for ARM/MIPS

Closes #4615

2 files changed, 28 insertions(+), 13 deletions(-)

lib
- std
  - os
    linux.zig
    test.zig

lib/std/os/linux.zig+28-9

 @@ -39,6 +39,13 @@ pub fn getauxval(index: usize) usize {
     return 0;
 }
+// Some architectures require 64bit parameters for some syscalls to be passed in
+// even-aligned register pair
+const require_aligned_register_pair = //
+    comptime builtin.arch.isMIPS() or
+    comptime builtin.arch.isARM() or
+    comptime builtin.arch.isThumb();
 /// Get the errno from a syscall return value, or 0 for no error.
 pub fn getErrno(r: usize) u12 {
     const signed_r = @bitCast(isize, r);
 @@ -318,14 +325,26 @@ pub fn symlinkat(existing: [*:0]const u8, newfd: i32, newpath: [*:0]const u8) us
 pub fn pread(fd: i32, buf: [*]u8, count: usize, offset: u64) usize {
     if (@hasDecl(@This(), "SYS_pread64")) {
-        return syscall5(
+        if (require_aligned_register_pair) {
-            SYS_pread64,
+            return syscall6(
-            @bitCast(usize, @as(isize, fd)),
+                SYS_pread64,
-            @ptrToInt(buf),
+                @bitCast(usize, @as(isize, fd)),
-            count,
+                @ptrToInt(buf),
-            @truncate(usize, offset),
+                count,
-            @truncate(usize, offset >> 32),
+                0,
-        );
+                @truncate(usize, offset),
+                @truncate(usize, offset >> 32),
+            );
+        } else {
+            return syscall5(
+                SYS_pread64,
+                @bitCast(usize, @as(isize, fd)),
+                @ptrToInt(buf),
+                count,
+                @truncate(usize, offset),
+                @truncate(usize, offset >> 32),
+            );
+        }
     } else {
         return syscall4(SYS_pread, @bitCast(usize, @as(isize, fd)), @ptrToInt(buf), count, offset);
     }
 @@ -344,7 +363,7 @@ pub fn faccessat(dirfd: i32, path: [*:0]const u8, mode: u32, flags: u32) usize {
 }
 pub fn pipe(fd: *[2]i32) usize {
-    if (builtin.arch == .mipsel) {
+    if (comptime builtin.arch.isMIPS()) {
         return syscall_pipe(fd);
     } else if (@hasDecl(@This(), "SYS_pipe")) {
         return syscall1(SYS_pipe, @ptrToInt(fd));

lib/std/os/test.zig-4

 @@ -45,10 +45,6 @@ fn testThreadIdFn(thread_id: *Thread.Id) void {
 }
 test "sendfile" {
-    if (std.Target.current.cpu.arch == .mipsel) {
-        // https://github.com/ziglang/zig/issues/4615
-        return error.SkipZigTest;
-    }
     try fs.makePath(a, "os_test_tmp");
     defer fs.deleteTree("os_test_tmp") catch {};