[COMMITTED 2.39 1/7] aarch64: Disable ZA state of SME in setjmp and sigsetjmp

[Yury Khrustalev]

Due to the nature of the ZA state, setjmp() should clear it in the
same manner as it is already done by longjmp.

Reviewed-by: Wilco Dijkstra  <Wilco.Dijkstra@arm.com>
(cherry picked from commit a7f6fd976c17b82dc198290b4ab7087f35855a0e)
(cherry picked from commit 1f57ffdf35334ab245544cbb88f3abf2e6c77c54)
(cherry picked from commit cdc1665bb188319b5f16ee05c04de7f2ba580e27)
---
 sysdeps/aarch64/setjmp.S | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/sysdeps/aarch64/setjmp.S b/sysdeps/aarch64/setjmp.S
index 43fdb1b2fb..e0c65cf035 100644
--- a/sysdeps/aarch64/setjmp.S
+++ b/sysdeps/aarch64/setjmp.S
@@ -37,6 +37,29 @@ ENTRY (__sigsetjmp)
 	PTR_ARG (0)
 
 1:
+
+#if IS_IN(libc)
+	/* Disable ZA state of SME in libc.a and libc.so, but not in ld.so.  */
+# if HAVE_AARCH64_PAC_RET
+	PACIASP
+	cfi_window_save
+# endif
+	stp	x29, x30, [sp, -16]!
+	cfi_adjust_cfa_offset (16)
+	cfi_rel_offset (x29, 0)
+	cfi_rel_offset (x30, 8)
+	mov	x29, sp
+	bl	__libc_arm_za_disable
+	ldp	x29, x30, [sp], 16
+	cfi_adjust_cfa_offset (-16)
+	cfi_restore (x29)
+	cfi_restore (x30)
+# if HAVE_AARCH64_PAC_RET
+	AUTIASP
+	cfi_window_save
+# endif
+#endif
+
 	stp	x19, x20, [x0, #JB_X19<<3]
 	stp	x21, x22, [x0, #JB_X21<<3]
 	stp	x23, x24, [x0, #JB_X23<<3]
-- 
2.47.3