From: Aurelien Jarno <aurelien@aurel32.net>
Date: Tue, 14 Dec 2021 21:44:35 +0000 (+0100)
Subject: riscv: align stack in clone [BZ #28702]
X-Git-Tag: glibc-2.35~221
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d2e594d71509faf36cf851a69370db34a4f5fa65;p=thirdparty%2Fglibc.git

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 12f91a20d3b..161e83c7e37 100644
--- 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.  */