[PATCH 4.19 085/287] x86: Fix return value of __setup handlers

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>

[ Upstream commit 12441ccdf5e2f5a01a46e344976cbbd3d46845c9 ]

__setup() handlers should return 1 to obsolete_checksetup() in
init/main.c to indicate that the boot option has been handled. A return
of 0 causes the boot option/value to be listed as an Unknown kernel
parameter and added to init's (limited) argument (no '=') or environment
(with '=') strings. So return 1 from these x86 __setup handlers.

Examples:

  Unknown kernel command line parameters "apicpmtimer
    BOOT_IMAGE=/boot/bzImage-517rc8 vdso=1 ring3mwait=disable", will be
    passed to user space.

  Run /sbin/init as init process
   with arguments:
     /sbin/init
     apicpmtimer
   with environment:
     HOME=/
     TERM=linux
     BOOT_IMAGE=/boot/bzImage-517rc8
     vdso=1
     ring3mwait=disable

Fixes: 2aae950b21e4 ("x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu")
Fixes: 77b52b4c5c66 ("x86: add "debugpat" boot option")
Fixes: e16fd002afe2 ("x86/cpufeature: Enable RING3MWAIT for Knights Landing")
Fixes: b8ce33590687 ("x86_64: convert to clock events")
Reported-by: Igor Zhbanov <i.zhbanov@xxxxxxxxxxxx>
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Link: https://lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@xxxxxxxxxxxx
Link: https://lore.kernel.org/r/20220314012725.26661-1-rdunlap@xxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/x86/entry/vdso/vma.c   | 2 +-
 arch/x86/kernel/apic/apic.c | 2 +-
 arch/x86/kernel/cpu/intel.c | 2 +-
 arch/x86/mm/pat.c           | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 46caca4d9141..a1c31bb23170 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -329,7 +329,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 static __init int vdso_setup(char *s)
 {
 	vdso64_enabled = simple_strtoul(s, NULL, 0);
-	return 0;
+	return 1;
 }
 __setup("vdso=", vdso_setup);
 #endif
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 9791828f3fcd..926939978c1c 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -166,7 +166,7 @@ static __init int setup_apicpmtimer(char *s)
 {
 	apic_calibrate_pmtmr = 1;
 	notsc_setup(NULL);
-	return 0;
+	return 1;
 }
 __setup("apicpmtimer", setup_apicpmtimer);
 #endif
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index a5287b18a63f..76692590eff8 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -71,7 +71,7 @@ static bool ring3mwait_disabled __read_mostly;
 static int __init ring3mwait_disable(char *__unused)
 {
 	ring3mwait_disabled = true;
-	return 0;
+	return 1;
 }
 __setup("ring3mwait=disable", ring3mwait_disable);
 
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 324e26d0607b..b33304c0042a 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -74,7 +74,7 @@ int pat_debug_enable;
 static int __init pat_debug_setup(char *str)
 {
 	pat_debug_enable = 1;
-	return 0;
+	return 1;
 }
 __setup("debugpat", pat_debug_setup);
 
-- 
2.35.1