linux-kernel - [RFC][PATCH 15/18] x86/xen: Make irq

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 21 Jun 2021 13:12:48 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     jpoimboe@...hat.com, tglx@...utronix.de
Cc:     linux-kernel@...r.kernel.org, peterz@...radead.org,
        joro@...tes.org, boris.ostrovsky@...cle.com, jgross@...e.com,
        x86@...nel.org, mbenes@...e.com
Subject: [RFC][PATCH 15/18] x86/xen: Make irq_disable() noinstr

vmlinux.o: warning: objtool: pv_ops[31]: native_irq_disable
vmlinux.o: warning: objtool: pv_ops[31]: __raw_callee_save_xen_irq_disable
vmlinux.o: warning: objtool: pv_ops[31]: xen_irq_disable_direct
vmlinux.o: warning: objtool: lock_is_held_type()+0x5b: call to pv_ops[31]() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
 arch/x86/kernel/paravirt.c |    7 ++++++-
 arch/x86/xen/irq.c         |    4 ++--
 arch/x86/xen/xen-asm.S     |    3 +--
 3 files changed, 9 insertions(+), 5 deletions(-)

--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -263,6 +263,11 @@ static noinstr void pv_native_irq_enable
 	native_irq_enable();
 }
 
+static noinstr void pv_native_irq_disable(void)
+{
+	native_irq_disable();
+}
+
 struct paravirt_patch_template pv_ops = {
 	/* Cpu ops. */
 	.cpu.io_delay		= native_io_delay,
@@ -306,7 +311,7 @@ struct paravirt_patch_template pv_ops =
 
 	/* Irq ops. */
 	.irq.save_fl		= __PV_IS_CALLEE_SAVE(native_save_fl),
-	.irq.irq_disable	= __PV_IS_CALLEE_SAVE(native_irq_disable),
+	.irq.irq_disable	= __PV_IS_CALLEE_SAVE(pv_native_irq_disable),
 	.irq.irq_enable		= __PV_IS_CALLEE_SAVE(pv_native_irq_enable),
 	.irq.safe_halt		= native_safe_halt,
 	.irq.halt		= native_halt,
--- a/arch/x86/xen/irq.c
+++ b/arch/x86/xen/irq.c
@@ -42,7 +42,7 @@ asmlinkage __visible noinstr unsigned lo
 }
 __PV_CALLEE_SAVE_REGS_THUNK(xen_save_fl, ".noinstr.text");
 
-asmlinkage __visible void xen_irq_disable(void)
+asmlinkage __visible noinstr void xen_irq_disable(void)
 {
 	/* There's a one instruction preempt window here.  We need to
 	   make sure we're don't switch CPUs between getting the vcpu
@@ -51,7 +51,7 @@ asmlinkage __visible void xen_irq_disabl
 	this_cpu_read(xen_vcpu)->evtchn_upcall_mask = 1;
 	preempt_enable_no_resched();
 }
-PV_CALLEE_SAVE_REGS_THUNK(xen_irq_disable);
+__PV_CALLEE_SAVE_REGS_THUNK(xen_irq_disable, ".noinstr.text");
 
 asmlinkage __visible noinstr void xen_irq_enable(void)
 {
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm.S
@@ -21,6 +21,7 @@
 #include <linux/init.h>
 #include <linux/linkage.h>
 
+.pushsection .noinstr.text, "ax"
 /*
  * Disabling events is simply a matter of making the event mask
  * non-zero.
@@ -30,8 +31,6 @@ SYM_FUNC_START(xen_irq_disable_direct)
 	ret
 SYM_FUNC_END(xen_irq_disable_direct)
 
-.pushsection .noinstr.text, "ax"
-
 /*
  * Force an event check by making a hypercall, but preserve regs
  * before making the call.