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authorAndreas Schwab <schwab@suse.de>2020-04-27 17:13:34 +0200
committerPalmer Dabbelt <palmerdabbelt@google.com>2020-05-04 14:22:34 -0700
commit0a9f2a6161dcd6be057f6c501453d28b3c4a3b0c (patch)
tree88aeef0ecf9413f999a43f48a49a5f8e8941cedb /arch
parentc749bb2d554825e007cbc43b791f54e124dadfce (diff)
riscv: add Linux note to vdso
The Linux note in the vdso allows glibc to check the running kernel version without having to issue the uname syscall. Signed-off-by: Andreas Schwab <schwab@suse.de> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/riscv/kernel/vdso/Makefile2
-rw-r--r--arch/riscv/kernel/vdso/note.S12
2 files changed, 13 insertions, 1 deletions
diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
index a4ee3a0e7d20..4c8b2a4a6a70 100644
--- a/arch/riscv/kernel/vdso/Makefile
+++ b/arch/riscv/kernel/vdso/Makefile
@@ -12,7 +12,7 @@ vdso-syms += getcpu
vdso-syms += flush_icache
# Files to link into the vdso
-obj-vdso = $(patsubst %, %.o, $(vdso-syms))
+obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o
# Build rules
targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-dummy.o
diff --git a/arch/riscv/kernel/vdso/note.S b/arch/riscv/kernel/vdso/note.S
new file mode 100644
index 000000000000..2a956c942211
--- /dev/null
+++ b/arch/riscv/kernel/vdso/note.S
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text.
+ * Here we can supply some information useful to userland.
+ */
+
+#include <linux/elfnote.h>
+#include <linux/version.h>
+
+ELFNOTE_START(Linux, 0, "a")
+ .long LINUX_VERSION_CODE
+ELFNOTE_END