LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, Peter Zijlstra <peterz@infradead.org>,
	Andy Lutomirski <luto@kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Jiri Kosina <jkosina@suse.cz>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Andrea Arcangeli <aarcange@redhat.com>,
	David Woodhouse <dwmw@amazon.co.uk>,
	Tim Chen <tim.c.chen@linux.intel.com>,
	Andi Kleen <ak@linux.intel.com>,
	Dave Hansen <dave.hansen@intel.com>,
	Casey Schaufler <casey.schaufler@intel.com>,
	Asit Mallick <asit.k.mallick@intel.com>,
	Arjan van de Ven <arjan@linux.intel.com>,
	Jon Masters <jcm@redhat.com>, Waiman Long <longman9394@gmail.com>,
	Greg KH <gregkh@linuxfoundation.org>,
	Dave Stewart <david.c.stewart@intel.com>,
	Kees Cook <keescook@chromium.org>
Subject: [patch V2 17/28] x86/speculation: Add command line control for indirect branch speculation
Date: Sun, 25 Nov 2018 19:33:45 +0100
Message-ID: <20181125185005.082720373@linutronix.de> (raw)
In-Reply-To: <20181125183328.318175777@linutronix.de>

[-- Attachment #0: x86-speculation-Add-command-line-control-for-indirect-branch-speculation.patch --]
[-- Type: text/plain, Size: 8993 bytes --]

Add command line control for user space indirect branch speculation
mitigations. The new option is: spectre_v2_user=

The initial options are:

    -  on:   Unconditionally enabled
    - off:   Unconditionally disabled
    -auto:   Kernel selects mitigation (default off for now)

When the spectre_v2= command line argument is either 'on' or 'off' this
implies that the application to application control follows that state even
if a contradicting spectre_v2_user= argument is supplied.

Originally-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
V1 -> V2: Change the option to spectre_v2_user=
---
 Documentation/admin-guide/kernel-parameters.txt |   32 +++++
 arch/x86/include/asm/nospec-branch.h            |   10 +
 arch/x86/kernel/cpu/bugs.c                      |  133 ++++++++++++++++++++----
 3 files changed, 156 insertions(+), 19 deletions(-)

--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4194,9 +4194,13 @@
 
 	spectre_v2=	[X86] Control mitigation of Spectre variant 2
 			(indirect branch speculation) vulnerability.
+			The default operation protects the kernel from
+			user space attacks.
 
-			on   - unconditionally enable
-			off  - unconditionally disable
+			on   - unconditionally enable, implies
+			       spectre_v2_user=on
+			off  - unconditionally disable, implies
+			       spectre_v2_user=off
 			auto - kernel detects whether your CPU model is
 			       vulnerable
 
@@ -4206,6 +4210,12 @@
 			CONFIG_RETPOLINE configuration option, and the
 			compiler with which the kernel was built.
 
+			Selecting 'on' will also enable the mitigation
+			against user space to user space task attacks.
+
+			Selecting 'off' will disable both the kernel and
+			the user space protections.
+
 			Specific mitigations can also be selected manually:
 
 			retpoline	  - replace indirect branches
@@ -4215,6 +4225,24 @@
 			Not specifying this option is equivalent to
 			spectre_v2=auto.
 
+	spectre_v2_user=
+			[X86] Control mitigation of Spectre variant 2
+		        (indirect branch speculation) vulnerability between
+		        user space tasks
+
+			on	- Unconditionally enable mitigations. Is
+				  enforced by spectre_v2=on
+
+			off     - Unconditionally disable mitigations. Is
+				  enforced by spectre_v2=off
+
+			auto    - Kernel selects the mitigation depending on
+				  the available CPU features and vulnerability.
+				  Default is off.
+
+			Not specifying this option is equivalent to
+			spectre_v2_user=auto.
+
 	spec_store_bypass_disable=
 			[HW] Control Speculative Store Bypass (SSB) Disable mitigation
 			(Speculative Store Bypass vulnerability)
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -3,6 +3,8 @@
 #ifndef _ASM_X86_NOSPEC_BRANCH_H_
 #define _ASM_X86_NOSPEC_BRANCH_H_
 
+#include <linux/static_key.h>
+
 #include <asm/alternative.h>
 #include <asm/alternative-asm.h>
 #include <asm/cpufeatures.h>
@@ -226,6 +228,12 @@ enum spectre_v2_mitigation {
 	SPECTRE_V2_IBRS_ENHANCED,
 };
 
+/* The indirect branch speculation control variants */
+enum spectre_v2_user_mitigation {
+	SPECTRE_V2_USER_NONE,
+	SPECTRE_V2_USER_STRICT,
+};
+
 /* The Speculative Store Bypass disable variants */
 enum ssb_mitigation {
 	SPEC_STORE_BYPASS_NONE,
@@ -303,6 +311,8 @@ do {									\
 	preempt_enable();						\
 } while (0)
 
+DECLARE_STATIC_KEY_FALSE(switch_to_cond_stibp);
+
 #endif /* __ASSEMBLY__ */
 
 /*
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -54,6 +54,9 @@ static u64 __ro_after_init x86_spec_ctrl
 u64 __ro_after_init x86_amd_ls_cfg_base;
 u64 __ro_after_init x86_amd_ls_cfg_ssbd_mask;
 
+/* Control conditional STIPB in switch_to() */
+DEFINE_STATIC_KEY_FALSE(switch_to_cond_stibp);
+
 void __init check_bugs(void)
 {
 	identify_boot_cpu();
@@ -199,6 +202,9 @@ static void x86_amd_ssb_disable(void)
 static enum spectre_v2_mitigation spectre_v2_enabled __ro_after_init =
 	SPECTRE_V2_NONE;
 
+static enum spectre_v2_user_mitigation spectre_v2_user __ro_after_init =
+	SPECTRE_V2_USER_NONE;
+
 #ifdef RETPOLINE
 static bool spectre_v2_bad_module;
 
@@ -237,6 +243,104 @@ enum spectre_v2_mitigation_cmd {
 	SPECTRE_V2_CMD_RETPOLINE_AMD,
 };
 
+enum spectre_v2_user_cmd {
+	SPECTRE_V2_USER_CMD_NONE,
+	SPECTRE_V2_USER_CMD_AUTO,
+	SPECTRE_V2_USER_CMD_FORCE,
+};
+
+static const char * const spectre_v2_user_strings[] = {
+	[SPECTRE_V2_USER_NONE]		= "User space: Vulnerable",
+	[SPECTRE_V2_USER_STRICT]	= "User space: Mitigation: STIBP protection",
+};
+
+static const struct {
+	const char			*option;
+	enum spectre_v2_user_cmd	cmd;
+	bool				secure;
+} v2_user_options[] __initdata = {
+	{ "auto",	SPECTRE_V2_USER_CMD_AUTO,	false },
+	{ "off",	SPECTRE_V2_USER_CMD_NONE,	false },
+	{ "on",		SPECTRE_V2_USER_CMD_FORCE,	true  },
+};
+
+static void __init spec_v2_user_print_cond(const char *reason, bool secure)
+{
+	if (boot_cpu_has_bug(X86_BUG_SPECTRE_V2) != secure)
+		pr_info("spectre_v2_user=%s forced on command line.\n", reason);
+}
+
+static enum spectre_v2_user_cmd __init
+spectre_v2_parse_user_cmdline(enum spectre_v2_mitigation_cmd v2_cmd)
+{
+	char arg[20];
+	int ret, i;
+
+	switch (v2_cmd) {
+	case SPECTRE_V2_CMD_NONE:
+		return SPECTRE_V2_USER_CMD_NONE;
+	case SPECTRE_V2_CMD_FORCE:
+		return SPECTRE_V2_USER_CMD_FORCE;
+	default:
+		break;
+	}
+
+	ret = cmdline_find_option(boot_command_line, "spectre_v2_user",
+				  arg, sizeof(arg));
+	if (ret < 0)
+		return SPECTRE_V2_USER_CMD_AUTO;
+
+	for (i = 0; i < ARRAY_SIZE(v2_user_options); i++) {
+		if (match_option(arg, ret, v2_user_options[i].option)) {
+			spec_v2_user_print_cond(v2_user_options[i].option,
+						v2_user_options[i].secure);
+			return v2_user_options[i].cmd;
+		}
+	}
+
+	pr_err("Unknown user space protection option (%s). Switching to AUTO select\n", arg);
+	return SPECTRE_V2_USER_CMD_AUTO;
+}
+
+static void __init
+spectre_v2_user_select_mitigation(enum spectre_v2_mitigation_cmd v2_cmd)
+{
+	enum spectre_v2_user_mitigation mode = SPECTRE_V2_USER_NONE;
+	bool smt_possible = IS_ENABLED(CONFIG_SMP);
+
+	if (!boot_cpu_has(X86_FEATURE_IBPB) && !boot_cpu_has(X86_FEATURE_STIBP))
+		return;
+
+	if (cpu_smt_control == CPU_SMT_FORCE_DISABLED ||
+	    cpu_smt_control == CPU_SMT_NOT_SUPPORTED)
+		smt_possible = false;
+
+	switch (spectre_v2_parse_user_cmdline(v2_cmd)) {
+	case SPECTRE_V2_USER_CMD_AUTO:
+	case SPECTRE_V2_USER_CMD_NONE:
+		goto set_mode;
+	case SPECTRE_V2_USER_CMD_FORCE:
+		mode = SPECTRE_V2_USER_STRICT;
+		break;
+	}
+
+	/* Initialize Indirect Branch Prediction Barrier */
+	if (boot_cpu_has(X86_FEATURE_IBPB)) {
+		setup_force_cpu_cap(X86_FEATURE_USE_IBPB);
+		pr_info("Spectre v2 mitigation: Enabling Indirect Branch Prediction Barrier\n");
+	}
+
+	/* If enhanced IBRS is enabled no STIPB required */
+	if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
+		return;
+
+set_mode:
+	spectre_v2_user = mode;
+	/* Only print the STIBP mode when SMT possible */
+	if (smt_possible)
+		pr_info("%s\n", spectre_v2_user_strings[mode]);
+}
+
 static const char * const spectre_v2_strings[] = {
 	[SPECTRE_V2_NONE]			= "Vulnerable",
 	[SPECTRE_V2_RETPOLINE_GENERIC]		= "Mitigation: Full generic retpoline",
@@ -385,12 +489,6 @@ static void __init spectre_v2_select_mit
 	setup_force_cpu_cap(X86_FEATURE_RSB_CTXSW);
 	pr_info("Spectre v2 / SpectreRSB mitigation: Filling RSB on context switch\n");
 
-	/* Initialize Indirect Branch Prediction Barrier if supported */
-	if (boot_cpu_has(X86_FEATURE_IBPB)) {
-		setup_force_cpu_cap(X86_FEATURE_USE_IBPB);
-		pr_info("Spectre v2 mitigation: Enabling Indirect Branch Prediction Barrier\n");
-	}
-
 	/*
 	 * Retpoline means the kernel is safe because it has no indirect
 	 * branches. Enhanced IBRS protects firmware too, so, enable restricted
@@ -407,23 +505,21 @@ static void __init spectre_v2_select_mit
 		pr_info("Enabling Restricted Speculation for firmware calls\n");
 	}
 
+	/* Set up IBPB and STIBP depending on the general spectre V2 command */
+	spectre_v2_user_select_mitigation(cmd);
+
 	/* Enable STIBP if appropriate */
 	arch_smt_update();
 }
 
 static bool stibp_needed(void)
 {
-	if (spectre_v2_enabled == SPECTRE_V2_NONE)
-		return false;
-
 	/* Enhanced IBRS makes using STIBP unnecessary. */
 	if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
 		return false;
 
-	if (!boot_cpu_has(X86_FEATURE_STIBP))
-		return false;
-
-	return true;
+	/* Check for strict user mitigation mode */
+	return spectre_v2_user == SPECTRE_V2_USER_STRICT;
 }
 
 static void update_stibp_msr(void *info)
@@ -844,10 +940,13 @@ static char *stibp_state(void)
 	if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
 		return "";
 
-	if (x86_spec_ctrl_base & SPEC_CTRL_STIBP)
-		return ", STIBP";
-	else
-		return "";
+	switch (spectre_v2_user) {
+	case SPECTRE_V2_USER_NONE:
+		return ", STIBP: disabled";
+	case SPECTRE_V2_USER_STRICT:
+		return ", STIBP: forced";
+	}
+	return "";
 }
 
 static char *ibpb_state(void)



  parent reply index

Thread overview: 112+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-25 18:33 [patch V2 00/28] x86/speculation: Remedy the STIBP/IBPB overhead Thomas Gleixner
2018-11-25 18:33 ` [patch V2 01/28] x86/speculation: Update the TIF_SSBD comment Thomas Gleixner
2018-11-28 14:20   ` [tip:x86/pti] " tip-bot for Tim Chen
2018-11-29 14:27   ` [patch V2 01/28] " Konrad Rzeszutek Wilk
2018-11-25 18:33 ` [patch V2 02/28] x86/speculation: Clean up spectre_v2_parse_cmdline() Thomas Gleixner
2018-11-28 14:20   ` [tip:x86/pti] " tip-bot for Tim Chen
2018-11-29 14:28   ` [patch V2 02/28] " Konrad Rzeszutek Wilk
2018-11-25 18:33 ` [patch V2 03/28] x86/speculation: Remove unnecessary ret variable in cpu_show_common() Thomas Gleixner
2018-11-28 14:21   ` [tip:x86/pti] " tip-bot for Tim Chen
2018-11-29 14:28   ` [patch V2 03/28] " Konrad Rzeszutek Wilk
2018-11-25 18:33 ` [patch V2 04/28] x86/speculation: Reorganize cpu_show_common() Thomas Gleixner
2018-11-26 15:08   ` Borislav Petkov
2018-11-28 14:22   ` [tip:x86/pti] x86/speculation: Move STIPB/IBPB string conditionals out of cpu_show_common() tip-bot for Tim Chen
2018-11-29 14:29   ` [patch V2 04/28] x86/speculation: Reorganize cpu_show_common() Konrad Rzeszutek Wilk
2018-11-25 18:33 ` [patch V2 05/28] x86/speculation: Disable STIBP when enhanced IBRS is in use Thomas Gleixner
2018-11-28 14:22   ` [tip:x86/pti] " tip-bot for Tim Chen
2018-11-29 14:35   ` [patch V2 05/28] " Konrad Rzeszutek Wilk
2018-11-25 18:33 ` [patch V2 06/28] x86/speculation: Rename SSBD update functions Thomas Gleixner
2018-11-26 15:24   ` Borislav Petkov
2018-11-28 14:23   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-29 14:37   ` [patch V2 06/28] " Konrad Rzeszutek Wilk
2018-11-25 18:33 ` [patch V2 07/28] x86/speculation: Reorganize speculation control MSRs update Thomas Gleixner
2018-11-26 15:47   ` Borislav Petkov
2018-11-28 14:23   ` [tip:x86/pti] " tip-bot for Tim Chen
2018-11-29 14:41   ` [patch V2 07/28] " Konrad Rzeszutek Wilk
2018-11-25 18:33 ` [patch V2 08/28] sched/smt: Make sched_smt_present track topology Thomas Gleixner
2018-11-28 14:24   ` [tip:x86/pti] " tip-bot for Peter Zijlstra (Intel)
2018-11-29 14:42   ` [patch V2 08/28] " Konrad Rzeszutek Wilk
2018-11-29 14:50     ` Konrad Rzeszutek Wilk
2018-11-29 15:48       ` Peter Zijlstra
2018-11-25 18:33 ` [patch V2 09/28] x86/Kconfig: Select SCHED_SMT if SMP enabled Thomas Gleixner
2018-11-28 14:24   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-29 14:44   ` [patch V2 09/28] " Konrad Rzeszutek Wilk
2018-11-25 18:33 ` [patch V2 10/28] sched/smt: Expose sched_smt_present static key Thomas Gleixner
2018-11-28 14:25   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-29 14:44   ` [patch V2 10/28] " Konrad Rzeszutek Wilk
2018-11-25 18:33 ` [patch V2 11/28] x86/speculation: Rework SMT state change Thomas Gleixner
2018-11-28 14:26   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-25 18:33 ` [patch V2 12/28] x86/l1tf: Show actual SMT state Thomas Gleixner
2018-11-28 14:26   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-25 18:33 ` [patch V2 13/28] x86/speculation: Reorder the spec_v2 code Thomas Gleixner
2018-11-26 22:21   ` Borislav Petkov
2018-11-28 14:27   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-25 18:33 ` [patch V2 14/28] x86/speculation: Mark string arrays const correctly Thomas Gleixner
2018-11-28 14:27   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-25 18:33 ` [patch V2 15/28] x86/speculataion: Mark command line parser data __initdata Thomas Gleixner
2018-11-28 14:28   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-25 18:33 ` [patch V2 16/28] x86/speculation: Unify conditional spectre v2 print functions Thomas Gleixner
2018-11-28 14:29   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-25 18:33 ` Thomas Gleixner [this message]
2018-11-28 14:29   ` [tip:x86/pti] x86/speculation: Add command line control for indirect branch speculation tip-bot for Thomas Gleixner
2018-11-25 18:33 ` [patch V2 18/28] x86/speculation: Prepare for per task indirect branch speculation control Thomas Gleixner
2018-11-27 17:25   ` Lendacky, Thomas
2018-11-27 19:51     ` Tim Chen
2018-11-28  9:39       ` Thomas Gleixner
2018-11-27 20:39     ` Thomas Gleixner
2018-11-27 20:42       ` Thomas Gleixner
2018-11-27 21:52         ` Lendacky, Thomas
2018-11-28 14:30   ` [tip:x86/pti] " tip-bot for Tim Chen
2018-11-25 18:33 ` [patch V2 19/28] x86/process: Consolidate and simplify switch_to_xtra() code Thomas Gleixner
2018-11-26 18:30   ` Borislav Petkov
2018-11-28 14:30   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-25 18:33 ` [patch V2 20/28] x86/speculation: Avoid __switch_to_xtra() calls Thomas Gleixner
2018-11-28 14:31   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-25 18:33 ` [patch V2 21/28] x86/speculation: Prepare for conditional IBPB in switch_mm() Thomas Gleixner
2018-11-25 19:11   ` Thomas Gleixner
2018-11-25 20:53   ` Andi Kleen
2018-11-25 22:20     ` Thomas Gleixner
2018-11-25 23:04       ` Andy Lutomirski
2018-11-26  7:10         ` Thomas Gleixner
2018-11-26 13:36           ` Ingo Molnar
2018-11-26  3:07       ` Andi Kleen
2018-11-26  6:50         ` Thomas Gleixner
2018-11-28 14:31   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-25 18:33 ` [patch V2 22/28] ptrace: Remove unused ptrace_may_access_sched() and MODE_IBRS Thomas Gleixner
2018-11-28 14:32   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-25 18:33 ` [patch V2 23/28] x86/speculation: Split out TIF update Thomas Gleixner
2018-11-28 14:33   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-25 18:33 ` [patch V2 24/28] x86/speculation: Prepare arch_smt_update() for PRCTL mode Thomas Gleixner
2018-11-27 20:18   ` Lendacky, Thomas
2018-11-27 20:30     ` Thomas Gleixner
2018-11-27 21:20       ` Lendacky, Thomas
2018-11-28 14:34   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-25 18:33 ` [patch V2 25/28] x86/speculation: Add prctl() control for indirect branch speculation Thomas Gleixner
2018-11-28 14:34   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-25 18:33 ` [patch V2 26/28] x86/speculation: Enable prctl mode for spectre_v2_user Thomas Gleixner
2018-11-26  7:56   ` Dominik Brodowski
2018-11-28 14:35   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-25 18:33 ` [patch V2 27/28] x86/speculation: Add seccomp Spectre v2 user space protection mode Thomas Gleixner
2018-11-25 19:35   ` Randy Dunlap
2018-11-25 20:40   ` Linus Torvalds
2018-11-25 20:52     ` Jiri Kosina
2018-11-25 22:28     ` Thomas Gleixner
2018-11-26 13:30       ` Ingo Molnar
2018-11-26 20:48       ` Andrea Arcangeli
2018-11-26 20:58         ` Thomas Gleixner
2018-11-26 21:52           ` Lendacky, Thomas
2018-11-27  0:37             ` Tim Chen
2018-12-04  1:38     ` Tim Chen
2018-12-04  8:39       ` Jiri Kosina
2018-12-04  9:43         ` Arjan van de Ven
2018-12-04  9:46         ` Arjan van de Ven
2018-12-04 17:20       ` Linus Torvalds
2018-12-04 18:58         ` Tim Chen
2018-11-28 14:35   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-12-04 18:45   ` [patch V2 27/28] " Dave Hansen
2018-11-25 18:33 ` [patch V2 28/28] x86/speculation: Provide IBPB always command line options Thomas Gleixner
2018-11-28 14:36   ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-11-26 13:37 ` [patch V2 00/28] x86/speculation: Remedy the STIBP/IBPB overhead Ingo Molnar
2018-11-28 14:24 ` Thomas Gleixner
2018-11-29 19:02   ` Tim Chen
2018-12-10 23:43 ` Pavel Machek

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20181125185005.082720373@linutronix.de \
    --to=tglx@linutronix.de \
    --cc=aarcange@redhat.com \
    --cc=ak@linux.intel.com \
    --cc=arjan@linux.intel.com \
    --cc=asit.k.mallick@intel.com \
    --cc=casey.schaufler@intel.com \
    --cc=dave.hansen@intel.com \
    --cc=david.c.stewart@intel.com \
    --cc=dwmw@amazon.co.uk \
    --cc=gregkh@linuxfoundation.org \
    --cc=jcm@redhat.com \
    --cc=jkosina@suse.cz \
    --cc=jpoimboe@redhat.com \
    --cc=keescook@chromium.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=longman9394@gmail.com \
    --cc=luto@kernel.org \
    --cc=peterz@infradead.org \
    --cc=thomas.lendacky@amd.com \
    --cc=tim.c.chen@linux.intel.com \
    --cc=torvalds@linux-foundation.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org linux-kernel@archiver.kernel.org
	public-inbox-index lkml


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/ public-inbox