riscv: Add vector registers to __SYSCALL_CLOBBERS

The Linux kernel ABI specifies that the vector registers are not preserved
across system calls, but the __SYSCALL_CLOBBERS macro doesn't mention them.
This could possibly lead to compilers trying to keep data in the vector
registers across the syscall leading to corruption.  Add the vector registers
to __SYSCALL_CLOBBERS when the vector extension is enabled.  If the vector
extension is enabled, then require GCC 15 or later and RVV 1.0 or later.

Fixes: 36960f0c76 ("RISC-V: Linux Syscall Interface")
Signed-off-by: Peter Bergner <bergner@tenstorrent.com>

diff --git a/sysdeps/riscv/preconfigure b/sysdeps/riscv/preconfigure
index a5de5ccb7d12397b0ec3b6782321b9d92363a77c..a96cd0d7f87c7fbfa1138ca6387ebe49ee2520ac 100644 (file)
--- a/sysdeps/riscv/preconfigure
+++ b/sysdeps/riscv/preconfigure
@@ -7,6 +7,7 @@ riscv*)
     flen=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | sed -n 's/^#define __riscv_flen \(.*\)/\1/p'`
     float_abi=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | sed -n 's/^#define __riscv_float_abi_\([^ ]*\) .*/\1/p'`
     atomic=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | grep '#define __riscv_atomic' | cut -d' ' -f2`
+    vector=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | sed -n 's/^#define __riscv_v \(.*\)/\1/p'`
 
     case "$xlen" in
     64 | 32)
@@ -55,6 +56,12 @@ riscv*)
        ;;
     esac
 
+    if test -n "$vector"; then
+       version=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | sed -n 's/^#define __GNUC__ \(.*\)/\1/p'`
+       test $version -lt 15 && as_fn_error 1 "glibc requires GCC 15 or later for the V extension" "$LINENO" 5
+       test $vector -lt "1000000" && as_fn_error 1 "glibc requires at least RVV 1.0 for the V extension" "$LINENO" 5
+    fi
+
     base_machine=riscv
     machine=riscv/rv$xlen/$float_machine
 

diff --git a/sysdeps/riscv/preconfigure.ac b/sysdeps/riscv/preconfigure.ac
index a5c30e0dbfc452e8f607bb18d761c55d7db1a356..f95ffe83fb76d113fe4fbc8a2d3936894d809069 100644 (file)
--- a/sysdeps/riscv/preconfigure.ac
+++ b/sysdeps/riscv/preconfigure.ac
@@ -7,6 +7,7 @@ riscv*)
     flen=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | sed -n 's/^#define __riscv_flen \(.*\)/\1/p'`
     float_abi=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | sed -n 's/^#define __riscv_float_abi_\([^ ]*\) .*/\1/p'`
     atomic=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | grep '#define __riscv_atomic' | cut -d' ' -f2`
+    vector=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | sed -n 's/^#define __riscv_v \(.*\)/\1/p'`
 
     case "$xlen" in
     64 | 32)
@@ -55,6 +56,12 @@ riscv*)
        ;;
     esac
 
+    if test -n "$vector"; then
+       version=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | sed -n 's/^#define __GNUC__ \(.*\)/\1/p'`
+       test $version -lt 15 && AC_MSG_ERROR([glibc requires GCC 15 or later for the V extension], [1])
+       test $vector -lt "1000000" && AC_MSG_ERROR([glibc requires at least RVV 1.0 for the V extension], [1])
+    fi
+
     base_machine=riscv
     machine=riscv/rv$xlen/$float_machine
 

diff --git a/sysdeps/unix/sysv/linux/riscv/sysdep.h b/sysdeps/unix/sysv/linux/riscv/sysdep.h
index 05e0e0523d3f744cd7ec1341afc5126746bc80e8..7f0eb070455a661cd367bf2ed7085918f299288b 100644 (file)
--- a/sysdeps/unix/sysv/linux/riscv/sysdep.h
+++ b/sysdeps/unix/sysv/linux/riscv/sysdep.h
@@ -355,7 +355,14 @@
        _sys_result;                                                    \
 })
 
+#ifdef __riscv_v
+# define __SYSCALL_CLOBBERS "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v8", "v9", \
+                            "v10", "v11", "v12", "v13", "v14", "v15", "v16", "v17", "v18", "v19", \
+                            "v20", "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", \
+                            "v30", "v31", "vl", "vtype", "vxrm", "vxsat", "memory"
+#else
 # define __SYSCALL_CLOBBERS "memory"
+#endif
 
 extern long int __syscall_error (long int neg_errno);