[PATCH v5 -next 13/16] x86: vdso: move the sysctl to arch/x86/entry/vdso/vdso32-setup.c
From: Kaixiong Yu <hidden>
Date: 2025-01-11 07:13:06
Also in:
linux-fsdevel, linux-mm, linux-nfs, linux-sh, lkml, netdev
Subsystem:
proc sysctl, the rest, x86 architecture (32-bit and 64-bit), x86 entry code, x86 vdso · Maintainers:
Kees Cook, Joel Granados, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski
When CONFIG_X86_32 is defined and CONFIG_UML is not defined, vdso_enabled belongs to arch/x86/entry/vdso/vdso32-setup.c. So, move it into its own file. Before this patch, vdso_enabled was allowed to be set to a value exceeding 1 on x86_32 architecture. After this patch is applied, vdso_enabled is not permitted to set the value more than 1. It does not matter, because according to the function load_vdso32(), only vdso_enabled is set to 1, VDSO would be enabled. Other values all mean "disabled". The same limitation could be seen in the function vdso32_setup(). Signed-off-by: Kaixiong Yu <redacted> Reviewed-by: Kees Cook <kees@kernel.org> --- v5: - Accept Brian Gerst's suggestion to reduce the preprocessor condition "#elif (defined(CONFIG_X86_32) && !defined(CONFIG_UML))" v4: - const qualify struct ctl_table vdso_table --- --- arch/x86/entry/vdso/vdso32-setup.c | 16 +++++++++++----- kernel/sysctl.c | 8 +------- 2 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/arch/x86/entry/vdso/vdso32-setup.c b/arch/x86/entry/vdso/vdso32-setup.c
index 76e4e74f35b5..8894013eea1d 100644
--- a/arch/x86/entry/vdso/vdso32-setup.c
+++ b/arch/x86/entry/vdso/vdso32-setup.c@@ -51,15 +51,17 @@ __setup("vdso32=", vdso32_setup); __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[] = { +static const struct ctl_table vdso_table[] = { { +#ifdef CONFIG_X86_64 .procname = "vsyscall32", +#else + .procname = "vdso_enabled", +#endif .data = &vdso32_enabled, .maxlen = sizeof(int), .mode = 0644,
@@ -71,10 +73,14 @@ static struct ctl_table abi_table2[] = { static __init int ia32_binfmt_init(void) { - register_sysctl("abi", abi_table2); +#ifdef CONFIG_X86_64 + /* Register vsyscall32 into the ABI table */ + register_sysctl("abi", vdso_table); +#else + register_sysctl_init("vm", vdso_table); +#endif return 0; } __initcall(ia32_binfmt_init); #endif /* CONFIG_SYSCTL */ -#endif /* CONFIG_X86_64 */
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 860dea8f1587..7ff07b7560b4 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c@@ -2013,17 +2013,11 @@ static struct ctl_table kern_table[] = { }; static struct ctl_table vm_table[] = { -#if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \ - (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL)) +#if defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL) { .procname = "vdso_enabled", -#ifdef CONFIG_X86_32 - .data = &vdso32_enabled, - .maxlen = sizeof(vdso32_enabled), -#else .data = &vdso_enabled, .maxlen = sizeof(vdso_enabled), -#endif .mode = 0644, .proc_handler = proc_dointvec, .extra1 = SYSCTL_ZERO,
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2.34.1