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authorJosh Poimboeuf <jpoimboe@redhat.com>2018-01-30 22:13:33 -0600
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-02-07 11:14:13 -0800
commit6e337065e6de2a79f2e508ec8e04fdc845edaeb7 (patch)
treeda651bff55244e1c73802add6e3d426fedf7a7e0
parent061c8e740e90bed5db0faafe3ba3e678e809d4ab (diff)
download96b-common-6e337065e6de2a79f2e508ec8e04fdc845edaeb7.tar.gz
x86/paravirt: Remove 'noreplace-paravirt' cmdline option
commit 12c69f1e94c89d40696e83804dd2f0965b5250cd The 'noreplace-paravirt' option disables paravirt patching, leaving the original pv indirect calls in place. That's highly incompatible with retpolines, unless we want to uglify paravirt even further and convert the paravirt calls to retpolines. As far as I can tell, the option doesn't seem to be useful for much other than introducing surprising corner cases and making the kernel vulnerable to Spectre v2. It was probably a debug option from the early paravirt days. So just remove it. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Juergen Gross <jgross@suse.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ashok Raj <ashok.raj@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jason Baron <jbaron@akamai.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Alok Kataria <akataria@vmware.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Dan Williams <dan.j.williams@intel.com> Link: https://lkml.kernel.org/r/20180131041333.2x6blhxirc2kclrq@treble Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt2
-rw-r--r--arch/x86/kernel/alternative.c14
2 files changed, 0 insertions, 16 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 46b26bfee27b..1e762c210f1b 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2742,8 +2742,6 @@
norandmaps Don't use address space randomization. Equivalent to
echo 0 > /proc/sys/kernel/randomize_va_space
- noreplace-paravirt [X86,IA-64,PV_OPS] Don't patch paravirt_ops
-
noreplace-smp [X86-32,SMP] Don't replace SMP instructions
with UP alternatives
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 30571fdaaf6f..a481763a3776 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -46,17 +46,6 @@ static int __init setup_noreplace_smp(char *str)
}
__setup("noreplace-smp", setup_noreplace_smp);
-#ifdef CONFIG_PARAVIRT
-static int __initdata_or_module noreplace_paravirt = 0;
-
-static int __init setup_noreplace_paravirt(char *str)
-{
- noreplace_paravirt = 1;
- return 1;
-}
-__setup("noreplace-paravirt", setup_noreplace_paravirt);
-#endif
-
#define DPRINTK(fmt, args...) \
do { \
if (debug_alternative) \
@@ -599,9 +588,6 @@ void __init_or_module apply_paravirt(struct paravirt_patch_site *start,
struct paravirt_patch_site *p;
char insnbuf[MAX_PATCH_LEN];
- if (noreplace_paravirt)
- return;
-
for (p = start; p < end; p++) {
unsigned int used;