[tip: x86/misc] x86: Fix return value of __setup handlers

[tip-bot2 for Randy Dunlap]

The following commit has been merged into the x86/misc branch of tip:

Commit-ID:     12441ccdf5e2f5a01a46e344976cbbd3d46845c9
Gitweb:        https://git.kernel.org/tip/12441ccdf5e2f5a01a46e344976cbbd3d46845c9
Author:        Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
AuthorDate:    Sun, 13 Mar 2022 18:27:25 -07:00
Committer:     Borislav Petkov <bp@xxxxxxx>
CommitterDate: Wed, 04 May 2022 16:47:57 +02:00

x86: Fix return value of __setup handlers

__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
---
 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(-)

diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 235a579..1000d45 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -438,7 +438,7 @@ bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
 static __init int vdso_setup(char *s)
 {
 	vdso64_enabled = simple_strtoul(s, NULL, 0);
-	return 0;
+	return 1;
 }
 __setup("vdso=", vdso_setup);
 
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index b70344b..ed7d9cf 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -170,7 +170,7 @@ 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 8321c43..350c247 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -91,7 +91,7 @@ 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/memtype.c b/arch/x86/mm/pat/memtype.c
index 4ba2a3e..d5ef64d 100644
--- a/arch/x86/mm/pat/memtype.c
+++ b/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);