From 5aaa7d0fbb885db646ebd6557afc8def93ff860f Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Fri, 27 Sep 2019 18:18:38 +0200
Subject: [PATCH 1/3] Avoid truncating mmap2 offsets if not multiple of page
 size

---
 lib/std/os/linux.zig | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/lib/std/os/linux.zig b/lib/std/os/linux.zig
index eb2f71cf99..9550518842 100644
--- a/lib/std/os/linux.zig
+++ b/lib/std/os/linux.zig
@@ -193,9 +193,29 @@ pub fn umount2(special: [*]const u8, flags: u32) usize {
 
 pub fn mmap(address: ?[*]u8, length: usize, prot: usize, flags: u32, fd: i32, offset: u64) usize {
     if (@hasDecl(@This(), "SYS_mmap2")) {
-        return syscall6(SYS_mmap2, @ptrToInt(address), length, prot, flags, @bitCast(usize, isize(fd)), @truncate(usize, offset / MMAP2_UNIT));
+        // Make sure the offset is also specified in multiples of page size
+        if ((offset & (MMAP2_UNIT - 1)) != 0)
+            return @bitCast(usize, isize(-EINVAL));
+
+        return syscall6(
+            SYS_mmap2,
+            @ptrToInt(address),
+            length,
+            prot,
+            flags,
+            @bitCast(usize, isize(fd)),
+            @truncate(usize, offset / MMAP2_UNIT),
+        );
     } else {
-        return syscall6(SYS_mmap, @ptrToInt(address), length, prot, flags, @bitCast(usize, isize(fd)), offset);
+        return syscall6(
+            SYS_mmap,
+            @ptrToInt(address),
+            length,
+            prot,
+            flags,
+            @bitCast(usize, isize(fd)),
+            offset,
+        );
     }
 }
 

From a220648198aafbd067ddbdc806d5d7ba50ed885b Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Fri, 27 Sep 2019 18:20:00 +0200
Subject: [PATCH 2/3] Backport patch for Musl libc

Allows musl to compile for mipsel targets.

https://www.openwall.com/lists/musl/2019/09/27/1/2
---
 lib/libc/musl/src/setjmp/mips/longjmp.S | 18 ++++++------------
 lib/libc/musl/src/setjmp/mips/setjmp.S  | 18 ++++++------------
 2 files changed, 12 insertions(+), 24 deletions(-)

diff --git a/lib/libc/musl/src/setjmp/mips/longjmp.S b/lib/libc/musl/src/setjmp/mips/longjmp.S
index fdb6c95d25..ecf4085538 100644
--- a/lib/libc/musl/src/setjmp/mips/longjmp.S
+++ b/lib/libc/musl/src/setjmp/mips/longjmp.S
@@ -12,18 +12,12 @@ longjmp:
 	addu    $2, $2, 1
 1:
 #ifndef __mips_soft_float
-	lwc1    $20, 56($4)
-	lwc1    $21, 60($4)
-	lwc1    $22, 64($4)
-	lwc1    $23, 68($4)
-	lwc1    $24, 72($4)
-	lwc1    $25, 76($4)
-	lwc1    $26, 80($4)
-	lwc1    $27, 84($4)
-	lwc1    $28, 88($4)
-	lwc1    $29, 92($4)
-	lwc1    $30, 96($4)
-	lwc1    $31, 100($4)
+	l.d     $f20, 56($4)
+	l.d     $f22, 64($4)
+	l.d     $f24, 72($4)
+	l.d     $f26, 80($4)
+	l.d     $f28, 88($4)
+	l.d     $f30, 96($4)
 #endif
 	lw      $ra,  0($4)
 	lw      $sp,  4($4)
diff --git a/lib/libc/musl/src/setjmp/mips/setjmp.S b/lib/libc/musl/src/setjmp/mips/setjmp.S
index 501d5264e6..7ae8832d51 100644
--- a/lib/libc/musl/src/setjmp/mips/setjmp.S
+++ b/lib/libc/musl/src/setjmp/mips/setjmp.S
@@ -22,18 +22,12 @@ setjmp:
 	sw      $30, 40($4)
 	sw      $28, 44($4)
 #ifndef __mips_soft_float
-	swc1    $20, 56($4)
-	swc1    $21, 60($4)
-	swc1    $22, 64($4)
-	swc1    $23, 68($4)
-	swc1    $24, 72($4)
-	swc1    $25, 76($4)
-	swc1    $26, 80($4)
-	swc1    $27, 84($4)
-	swc1    $28, 88($4)
-	swc1    $29, 92($4)
-	swc1    $30, 96($4)
-	swc1    $31, 100($4)
+	s.d     $f20, 56($4)
+	s.d     $f22, 64($4)
+	s.d     $f24, 72($4)
+	s.d     $f26, 80($4)
+	s.d     $f28, 88($4)
+	s.d     $f30, 96($4)
 #endif
 	jr      $ra
 	li      $2, 0

From 9ad0541f2c06e0eb3419b3da7fe721affa3aa3b5 Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Fri, 27 Sep 2019 18:20:17 +0200
Subject: [PATCH 3/3] Enable mipsel+libc tests on CI

---
 test/tests.zig | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/test/tests.zig b/test/tests.zig
index 4a9b2c89e6..3c6baeb360 100644
--- a/test/tests.zig
+++ b/test/tests.zig
@@ -140,6 +140,16 @@ const test_targets = [_]TestTarget{
             },
         },
     },
+    TestTarget{
+        .target = Target{
+            .Cross = CrossTarget{
+                .os = .linux,
+                .arch = .mipsel,
+                .abi = .musl,
+            },
+        },
+        .link_libc = true,
+    },
 
     TestTarget{
         .target = Target{