riscv64 brk()/sbrk() implementations,

based off a combination of aarch64/powerpc64
ok kettenis@

diff --git a/lib/libc/arch/riscv64/sys/brk.S b/lib/libc/arch/riscv64/sys/brk.S
new file mode 100644 (file)
index 0000000..74a1c2a
--- /dev/null
+++ b/lib/libc/arch/riscv64/sys/brk.S
@@ -0,0 +1,58 @@
+/*     $OpenBSD: brk.S,v 1.1 2021/05/04 04:17:53 drahn Exp $   */
+/*
+ * Copyright (c) 2021 Dale Rahn <drahn@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "SYS.h"
+
+       .extern __curbrk
+       .extern _C_LABEL(_end)
+
+       .data
+       .align 3
+__minbrk:
+       .dword _C_LABEL(_end)
+       
+
+       .weak   brk
+ENTRY(brk)
+       RETGUARD_SETUP(brk, t6)
+       lla     t1, _C_LABEL(__minbrk)
+       ld      t5, 0(t1)
+       bgeu    a0, t5, .L_brk_call
+       mv      a0, t5
+       
+.L_brk_call:
+       mv      a2, a0
+       lla     t1, _C_LABEL(__curbrk)
+
+       li t0, SYS_break
+       ecall
+
+       /* check for error */
+       beqz    t0, .L_brk_ok
+
+       sw      a0, TP_OFFSET_ERRNO(tp)
+       li      a0, -1
+       j       .L_done
+
+       /* update, __curbrk and return */
+.L_brk_ok:
+       sd      a2, 0(t1)
+       li      a0, 0           /* # return 0 */
+.L_done:
+       RETGUARD_CHECK(brk, t6);
+       ret
+END(brk)

diff --git a/lib/libc/arch/riscv64/sys/sbrk.S b/lib/libc/arch/riscv64/sys/sbrk.S
new file mode 100644 (file)
index 0000000..02d02d3
--- /dev/null
+++ b/lib/libc/arch/riscv64/sys/sbrk.S
@@ -0,0 +1,50 @@
+/*     $OpenBSD: sbrk.S,v 1.1 2021/05/04 04:17:53 drahn Exp $  */
+/*
+ * Copyright (c) 2021 Dale Rahn <drahn@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "SYS.h"
+
+       .extern _C_LABEL(_end)
+
+       .data
+       .align  3
+       .globl  __curbrk
+       .hidden __curbrk
+       .type   __curbrk,@object
+__curbrk:
+       .dword _C_LABEL(_end)
+       END(__curbrk)
+       
+       .weak   sbrk
+ENTRY(sbrk)
+       RETGUARD_SETUP(sbrk, t6)
+
+       lla     t1, _C_LABEL(__curbrk)
+       ld      a2, 0(t1)
+       add     a0, a0, a2      // compute current break
+       mv      t3, a0
+       SYSTRAP(break)
+       beqz    t0, .L_sbrk_ok
+       sw      a0, TP_OFFSET_ERRNO(tp)
+       li      a0, -1
+       j       .L_sbrk_fail
+.L_sbrk_ok:
+       sd      t3, 0(t1)       // save current val of curbrk from above
+       mv      a0, a2          // return old val of curbrk from above
+.L_sbrk_fail:
+       RETGUARD_CHECK(sbrk, t6);
+       ret
+END(sbrk)