[PATCH] x86: fix return value of __setup handlers

[Randy Dunlap]

__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")
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Reported-by: Igor Zhbanov <i.zhbanov@xxxxxxxxxxxx>
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@xxxxxxxxxxxx
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@xxxxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: x86@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/memtype.c   |    2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

--- lnx-517-rc8.orig/arch/x86/entry/vdso/vma.c
+++ lnx-517-rc8/arch/x86/entry/vdso/vma.c
@@ -438,7 +438,7 @@ bool arch_syscall_is_vdso_sigreturn(stru
 static __init int vdso_setup(char *s)
 {
 	vdso64_enabled = simple_strtoul(s, NULL, 0);
-	return 0;
+	return 1;
 }
 __setup("vdso=", vdso_setup);
 
--- lnx-517-rc8.orig/arch/x86/mm/pat/memtype.c
+++ lnx-517-rc8/arch/x86/mm/pat/memtype.c
@@ -101,7 +101,7 @@ 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);
 
--- lnx-517-rc8.orig/arch/x86/kernel/apic/apic.c
+++ lnx-517-rc8/arch/x86/kernel/apic/apic.c
@@ -170,7 +170,7 @@ static __init int setup_apicpmtimer(char
 {
 	apic_calibrate_pmtmr = 1;
 	notsc_setup(NULL);
-	return 0;
+	return 1;
 }
 __setup("apicpmtimer", setup_apicpmtimer);
 #endif
--- lnx-517-rc8.orig/arch/x86/kernel/cpu/intel.c
+++ lnx-517-rc8/arch/x86/kernel/cpu/intel.c
@@ -91,7 +91,7 @@ static bool ring3mwait_disabled __read_m
 static int __init ring3mwait_disable(char *__unused)
 {
 	ring3mwait_disabled = true;
-	return 0;
+	return 1;
 }
 __setup("ring3mwait=disable", ring3mwait_disable);