riscv: align stack in clone [BZ #28702]

The RISC-V ABI [1] mandates that "the stack pointer shall be aligned to
a 128-bit boundary upon procedure entry". This as not the case in clone.

This fixes the misc/tst-misalign-clone-internal and
misc/tst-misalign-clone tests.

Fixes bug 28702.

[1] https://github.com/riscv-non-isa/riscv-elf-psabi-doc

diff --git a/sysdeps/unix/sysv/linux/riscv/clone.S b/sysdeps/unix/sysv/linux/riscv/clone.S
index 12f91a20d3bb34f5ac7183763fa11386bde233df..161e83c7e3786b8d719726b34ea1c9be8268a835 100644 (file)
--- a/sysdeps/unix/sysv/linux/riscv/clone.S
+++ b/sysdeps/unix/sysv/linux/riscv/clone.S
@@ -32,6 +32,9 @@
        .text
 LEAF (__clone)
 
+       /* Align stack to a 128-bit boundary as per RISC-V ABI.  */
+       andi            a1,a1,ALMASK
+
        /* Sanity check arguments.  */
        beqz            a0,L (invalid)  /* No NULL function pointers.  */
        beqz            a1,L (invalid)  /* No NULL stack pointers.  */