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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /arch/x86/entry/vdso/vdso32-setup.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/entry/vdso/vdso32-setup.c')
-rw-r--r--arch/x86/entry/vdso/vdso32-setup.c81
1 files changed, 81 insertions, 0 deletions
diff --git a/arch/x86/entry/vdso/vdso32-setup.c b/arch/x86/entry/vdso/vdso32-setup.c
new file mode 100644
index 0000000000..f3b3cacbcb
--- /dev/null
+++ b/arch/x86/entry/vdso/vdso32-setup.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) Copyright 2002 Linus Torvalds
+ * Portions based on the vdso-randomization code from exec-shield:
+ * Copyright(C) 2005-2006, Red Hat, Inc., Ingo Molnar
+ *
+ * This file contains the needed initializations to support sysenter.
+ */
+
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/kernel.h>
+#include <linux/mm_types.h>
+#include <linux/elf.h>
+
+#include <asm/processor.h>
+#include <asm/vdso.h>
+
+#ifdef CONFIG_COMPAT_VDSO
+#define VDSO_DEFAULT 0
+#else
+#define VDSO_DEFAULT 1
+#endif
+
+/*
+ * Should the kernel map a VDSO page into processes and pass its
+ * address down to glibc upon exec()?
+ */
+unsigned int __read_mostly vdso32_enabled = VDSO_DEFAULT;
+
+static int __init vdso32_setup(char *s)
+{
+ vdso32_enabled = simple_strtoul(s, NULL, 0);
+
+ if (vdso32_enabled > 1) {
+ pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n");
+ vdso32_enabled = 0;
+ }
+
+ return 1;
+}
+
+/*
+ * For consistency, the argument vdso32=[012] affects the 32-bit vDSO
+ * behavior on both 64-bit and 32-bit kernels.
+ * On 32-bit kernels, vdso=[012] means the same thing.
+ */
+__setup("vdso32=", vdso32_setup);
+
+#ifdef CONFIG_X86_32
+__setup_param("vdso=", vdso_setup, vdso32_setup, 0);
+#endif
+
+#ifdef CONFIG_X86_64
+
+#ifdef CONFIG_SYSCTL
+/* Register vsyscall32 into the ABI table */
+#include <linux/sysctl.h>
+
+static struct ctl_table abi_table2[] = {
+ {
+ .procname = "vsyscall32",
+ .data = &vdso32_enabled,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE,
+ },
+ {}
+};
+
+static __init int ia32_binfmt_init(void)
+{
+ register_sysctl("abi", abi_table2);
+ return 0;
+}
+__initcall(ia32_binfmt_init);
+#endif /* CONFIG_SYSCTL */
+
+#endif /* CONFIG_X86_64 */