Skip to contentSkip to conversation

Linux 5.4.184

DISCUSSION Greg Kroah-Hartman 1 participant 2 messages Mar 11, 2022 Stable branch

lore
Share & tools
lore

Greg Kroah-Hartman

author maintainer
#0 lore raw

I'm announcing the release of the 5.4.184 kernel.

All users of the 5.4 kernel series must upgrade.

The updated 5.4.y git tree can be found at:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git linux-5.4.y
and can be browsed at the normal kernel.org git web browser:
https://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=summary

thanks,

greg k-h

------------

 Documentation/admin-guide/hw-vuln/spectre.rst   |   48 +++--
 Documentation/admin-guide/kernel-parameters.txt |    8 
 Makefile                                        |    2 
 arch/arm/include/asm/assembler.h                |   10 +
 arch/arm/include/asm/spectre.h                  |   32 +++
 arch/arm/kernel/Makefile                        |    2 
 arch/arm/kernel/entry-armv.S                    |   79 ++++++++
 arch/arm/kernel/entry-common.S                  |   24 ++
 arch/arm/kernel/spectre.c                       |   71 +++++++
 arch/arm/kernel/traps.c                         |   65 ++++++-
 arch/arm/kernel/vmlinux.lds.h                   |   43 +++-
 arch/arm/mm/Kconfig                             |   11 +
 arch/arm/mm/proc-v7-bugs.c                      |  200 +++++++++++++++++++---
 arch/x86/include/asm/cpufeatures.h              |    2 
 arch/x86/include/asm/nospec-branch.h            |   16 +
 arch/x86/kernel/cpu/bugs.c                      |  216 +++++++++++++++++-------
 drivers/acpi/ec.c                               |   10 -
 drivers/acpi/sleep.c                            |   14 +
 drivers/block/xen-blkfront.c                    |   63 ++++---
 drivers/firmware/psci/psci.c                    |   15 +
 drivers/net/xen-netfront.c                      |   54 +++---
 drivers/scsi/xen-scsifront.c                    |    3 
 drivers/xen/gntalloc.c                          |   25 --
 drivers/xen/grant-table.c                       |   71 ++++---
 drivers/xen/pvcalls-front.c                     |    8 
 drivers/xen/xenbus/xenbus_client.c              |   24 +-
 include/linux/arm-smccc.h                       |   74 ++++++++
 include/linux/bpf.h                             |   12 +
 include/xen/grant_table.h                       |   19 +-
 kernel/sysctl.c                                 |    8 
 net/9p/trans_xen.c                              |   14 -
 tools/arch/x86/include/asm/cpufeatures.h        |    2 
 32 files changed, 969 insertions(+), 276 deletions(-)

Borislav Petkov (1):
x86/speculation: Merge one test in spectre_v2_user_select_mitigation()

Emmanuel Gil Peyrot (1):
ARM: fix build error when BPF_SYSCALL is disabled

Greg Kroah-Hartman (2):
Revert "ACPI: PM: s2idle: Cancel wakeup before dispatching EC GPE" Linux 5.4.184

Josh Poimboeuf (3):
x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation reporting x86/speculation: Warn about Spectre v2 LFENCE mitigation x86/speculation: Warn about eIBRS + LFENCE + Unprivileged eBPF + SMT

Juergen Gross (11):
xen/xenbus: don't let xenbus_grant_ring() remove grants in error case xen/grant-table: add gnttab_try_end_foreign_access() xen/blkfront: don't use gnttab_query_foreign_access() for mapped status xen/netfront: don't use gnttab_query_foreign_access() for mapped status xen/scsifront: don't use gnttab_query_foreign_access() for mapped status xen/gntalloc: don't use gnttab_query_foreign_access()
xen: remove gnttab_query_foreign_access()
xen/9p: use alloc/free_pages_exact()
xen/pvcalls: use alloc/free_pages_exact()
xen/gnttab: fix gnttab_end_foreign_access() without page specified xen/netfront: react properly to failing gnttab_end_foreign_access_ref()

Kim Phillips (2):
x86/speculation: Use generic retpoline by default on AMD x86/speculation: Update link to AMD speculation whitepaper

Mark Rutland (1):

      arm/arm64: smccc/psci: add arm_smccc_1_1_get_conduit()

Nathan Chancellor (1):
ARM: Do not use NOCROSSREFS directive with ld.lld

Peter Zijlstra (3):
x86,bugs: Unconditionally allow spectre_v2=retpoline,amd x86/speculation: Add eIBRS + Retpoline options Documentation/hw-vuln: Update spectre doc

Peter Zijlstra (Intel) (1):
x86/speculation: Rename RETPOLINE_AMD to RETPOLINE_LFENCE

Russell King (Oracle) (7):
ARM: report Spectre v2 status through sysfs
ARM: early traps initialisation
ARM: use LOADADDR() to get load address of sections
ARM: Spectre-BHB workaround
ARM: include unprivileged BPF status in Spectre V2 reporting
ARM: fix co-processor register typo
ARM: fix build warning in proc-v7-bugs.c

Steven Price (1):
arm/arm64: Provide a wrapper for SMCCC 1.1 calls

author maintainer
#1 lore raw
Documentation/admin-guide/hw-vuln/spectre.rst +32 -16
index 985181dba0ba..6bd97cd50d62 100644
@@ -60,8 +60,8 @@ privileged data touched during the speculative execution.
 Spectre variant 1 attacks take advantage of speculative execution of
 conditional branches, while Spectre variant 2 attacks use speculative
 execution of indirect branches to leak privileged memory.
-See :ref:`[1] <spec_ref1>` :ref:`[5] <spec_ref5>` :ref:`[7] <spec_ref7>`
-:ref:`[10] <spec_ref10>` :ref:`[11] <spec_ref11>`.
+See :ref:`[1] <spec_ref1>` :ref:`[5] <spec_ref5>` :ref:`[6] <spec_ref6>`
+:ref:`[7] <spec_ref7>` :ref:`[10] <spec_ref10>` :ref:`[11] <spec_ref11>`.
 
 Spectre variant 1 (Bounds Check Bypass)
 ---------------------------------------
@@ -131,6 +131,19 @@ steer its indirect branch speculations to gadget code, and measure the
 speculative execution's side effects left in level 1 cache to infer the
 victim's data.
 
+Yet another variant 2 attack vector is for the attacker to poison the
+Branch History Buffer (BHB) to speculatively steer an indirect branch
+to a specific Branch Target Buffer (BTB) entry, even if the entry isn't
+associated with the source address of the indirect branch. Specifically,
+the BHB might be shared across privilege levels even in the presence of
+Enhanced IBRS.
+
+Currently the only known real-world BHB attack vector is via
+unprivileged eBPF. Therefore, it's highly recommended to not enable
+unprivileged eBPF, especially when eIBRS is used (without retpolines).
+For a full mitigation against BHB attacks, it's recommended to use
+retpolines (or eIBRS combined with retpolines).
+
 Attack scenarios
 ----------------
 
@@ -364,13 +377,15 @@ The possible values in this file are:
 
   - Kernel status:
 
-  ====================================  =================================
-  'Not affected'                        The processor is not vulnerable
-  'Vulnerable'                          Vulnerable, no mitigation
-  'Mitigation: Full generic retpoline'  Software-focused mitigation
-  'Mitigation: Full AMD retpoline'      AMD-specific software mitigation
-  'Mitigation: Enhanced IBRS'           Hardware-focused mitigation
-  ====================================  =================================
+  ========================================  =================================
+  'Not affected'                            The processor is not vulnerable
+  'Mitigation: None'                        Vulnerable, no mitigation
+  'Mitigation: Retpolines'                  Use Retpoline thunks
+  'Mitigation: LFENCE'                      Use LFENCE instructions
+  'Mitigation: Enhanced IBRS'               Hardware-focused mitigation
+  'Mitigation: Enhanced IBRS + Retpolines'  Hardware-focused + Retpolines
+  'Mitigation: Enhanced IBRS + LFENCE'      Hardware-focused + LFENCE
+  ========================================  =================================
 
   - Firmware status: Show if Indirect Branch Restricted Speculation (IBRS) is
     used to protect against Spectre variant 2 attacks when calling firmware (x86 only).
@@ -584,12 +599,13 @@ kernel command line.
 
 		Specific mitigations can also be selected manually:
 
-		retpoline
-					replace indirect branches
-		retpoline,generic
-					google's original retpoline
-		retpoline,amd
-					AMD-specific minimal thunk
+                retpoline               auto pick between generic,lfence
+                retpoline,generic       Retpolines
+                retpoline,lfence        LFENCE; indirect branch
+                retpoline,amd           alias for retpoline,lfence
+                eibrs                   enhanced IBRS
+                eibrs,retpoline         enhanced IBRS + Retpolines
+                eibrs,lfence            enhanced IBRS + LFENCE
 
 		Not specifying this option is equivalent to
 		spectre_v2=auto.
@@ -730,7 +746,7 @@ AMD white papers:
 
 .. _spec_ref6:
 
-[6] `Software techniques for managing speculation on AMD processors <https://developer.amd.com/wp-content/resources/90343-B_SoftwareTechniquesforManagingSpeculation_WP_7-18Update_FNL.pdf>`_.
+[6] `Software techniques for managing speculation on AMD processors <https://developer.amd.com/wp-content/resources/Managing-Speculation-on-AMD-Processors.pdf>`_.
 
 ARM white papers:
 
Documentation/admin-guide/kernel-parameters.txt +6 -2
index 165abcb656c5..979423e1b639 100644
@@ -4493,8 +4493,12 @@
 			Specific mitigations can also be selected manually:
 
 			retpoline	  - replace indirect branches
-			retpoline,generic - google's original retpoline
-			retpoline,amd     - AMD-specific minimal thunk
+			retpoline,generic - Retpolines
+			retpoline,lfence  - LFENCE; indirect branch
+			retpoline,amd     - alias for retpoline,lfence
+			eibrs		  - enhanced IBRS
+			eibrs,retpoline   - enhanced IBRS + Retpolines
+			eibrs,lfence      - enhanced IBRS + LFENCE
 
 			Not specifying this option is equivalent to
 			spectre_v2=auto.
Makefile +1 -1
index a94b5ea499e1..e914e1a8a7d2 100644
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 VERSION = 5
 PATCHLEVEL = 4
-SUBLEVEL = 183
+SUBLEVEL = 184
 EXTRAVERSION =
 NAME = Kleptomaniac Octopus
 
arch/arm/include/asm/assembler.h +10 -0
index 3546d294d55f..6b3e64e19fb6 100644
@@ -107,6 +107,16 @@
 	.endm
 #endif
 
+#if __LINUX_ARM_ARCH__ < 7
+	.macro	dsb, args
+	mcr	p15, 0, r0, c7, c10, 4
+	.endm
+
+	.macro	isb, args
+	mcr	p15, 0, r0, c7, c5, 4
+	.endm
+#endif
+
 	.macro asm_trace_hardirqs_off, save=1
 #if defined(CONFIG_TRACE_IRQFLAGS)
 	.if \save
arch/arm/include/asm/spectre.h new file +32 -0
new file mode 100644
index 000000000000..d1fa5607d3aa
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ASM_SPECTRE_H
+#define __ASM_SPECTRE_H
+
+enum {
+	SPECTRE_UNAFFECTED,
+	SPECTRE_MITIGATED,
+	SPECTRE_VULNERABLE,
+};
+
+enum {
+	__SPECTRE_V2_METHOD_BPIALL,
+	__SPECTRE_V2_METHOD_ICIALLU,
+	__SPECTRE_V2_METHOD_SMC,
+	__SPECTRE_V2_METHOD_HVC,
+	__SPECTRE_V2_METHOD_LOOP8,
+};
+
+enum {
+	SPECTRE_V2_METHOD_BPIALL = BIT(__SPECTRE_V2_METHOD_BPIALL),
+	SPECTRE_V2_METHOD_ICIALLU = BIT(__SPECTRE_V2_METHOD_ICIALLU),
+	SPECTRE_V2_METHOD_SMC = BIT(__SPECTRE_V2_METHOD_SMC),
+	SPECTRE_V2_METHOD_HVC = BIT(__SPECTRE_V2_METHOD_HVC),
+	SPECTRE_V2_METHOD_LOOP8 = BIT(__SPECTRE_V2_METHOD_LOOP8),
+};
+
+void spectre_v2_update_state(unsigned int state, unsigned int methods);
+
+int spectre_bhb_update_vectors(unsigned int method);
+
+#endif
arch/arm/kernel/Makefile +2 -0
index 8b679e2ca3c3..dc31426cae6d 100644
@@ -106,4 +106,6 @@ endif
 
 obj-$(CONFIG_HAVE_ARM_SMCCC)	+= smccc-call.o
 
+obj-$(CONFIG_GENERIC_CPU_VULNERABILITIES) += spectre.o
+
 extra-y := $(head-y) vmlinux.lds
arch/arm/kernel/entry-armv.S +73 -6

111 lines not on this page · raw message

arch/arm/kernel/entry-common.S +24 -0
index 271cb8a1eba1..bd619da73c84 100644
@@ -162,6 +162,29 @@ ENDPROC(ret_from_fork)
  *-----------------------------------------------------------------------------
  */
 
+	.align	5
+#ifdef CONFIG_HARDEN_BRANCH_HISTORY
+ENTRY(vector_bhb_loop8_swi)
+	sub	sp, sp, #PT_REGS_SIZE
+	stmia	sp, {r0 - r12}
+	mov	r8, #8
+1:	b	2f
+2:	subs	r8, r8, #1
+	bne	1b
+	dsb
+	isb
+	b	3f
+ENDPROC(vector_bhb_loop8_swi)
+
+	.align	5
+ENTRY(vector_bhb_bpiall_swi)
+	sub	sp, sp, #PT_REGS_SIZE
+	stmia	sp, {r0 - r12}
+	mcr	p15, 0, r8, c7, c5, 6	@ BPIALL
+	isb
+	b	3f
+ENDPROC(vector_bhb_bpiall_swi)
+#endif
 	.align	5
 ENTRY(vector_swi)
 #ifdef CONFIG_CPU_V7M
@@ -169,6 +192,7 @@ ENTRY(vector_swi)
 #else
 	sub	sp, sp, #PT_REGS_SIZE
 	stmia	sp, {r0 - r12}			@ Calling r0 - r12
+3:
  ARM(	add	r8, sp, #S_PC		)
  ARM(	stmdb	r8, {sp, lr}^		)	@ Calling sp, lr
  THUMB(	mov	r8, sp			)
arch/arm/kernel/spectre.c new file +71 -0

71 lines not on this page · raw message

arch/arm/kernel/traps.c +59 -6

92 lines not on this page · raw message

arch/arm/kernel/vmlinux.lds.h +34 -9

59 lines not on this page · raw message

arch/arm/mm/Kconfig +11 -0
index 64cce0c8560a..00ffee644372 100644
@@ -833,6 +833,7 @@ config CPU_BPREDICT_DISABLE
 
 config CPU_SPECTRE
 	bool
+	select GENERIC_CPU_VULNERABILITIES
 
 config HARDEN_BRANCH_PREDICTOR
 	bool "Harden the branch predictor against aliasing attacks" if EXPERT
@@ -853,6 +854,16 @@ config HARDEN_BRANCH_PREDICTOR
 
 	   If unsure, say Y.
 
+config HARDEN_BRANCH_HISTORY
+	bool "Harden Spectre style attacks against branch history" if EXPERT
+	depends on CPU_SPECTRE
+	default y
+	help
+	  Speculation attacks against some high-performance processors can
+	  make use of branch history to influence future speculation. When
+	  taking an exception, a sequence of branches overwrites the branch
+	  history, or branch history is invalidated.
+
 config TLS_REG_EMUL
 	bool
 	select NEED_KUSER_HELPERS
arch/arm/mm/proc-v7-bugs.c +173 -27

281 lines not on this page · raw message

arch/x86/include/asm/cpufeatures.h +1 -1
index d912457f56a7..f48905f796e9 100644
@@ -202,7 +202,7 @@
 #define X86_FEATURE_SME			( 7*32+10) /* AMD Secure Memory Encryption */
 #define X86_FEATURE_PTI			( 7*32+11) /* Kernel Page Table Isolation enabled */
 #define X86_FEATURE_RETPOLINE		( 7*32+12) /* "" Generic Retpoline mitigation for Spectre variant 2 */
-#define X86_FEATURE_RETPOLINE_AMD	( 7*32+13) /* "" AMD Retpoline mitigation for Spectre variant 2 */
+#define X86_FEATURE_RETPOLINE_LFENCE	( 7*32+13) /* "" Use LFENCE for Spectre variant 2 */
 #define X86_FEATURE_INTEL_PPIN		( 7*32+14) /* Intel Processor Inventory Number */
 #define X86_FEATURE_CDP_L2		( 7*32+15) /* Code and Data Prioritization L2 */
 #define X86_FEATURE_MSR_SPEC_CTRL	( 7*32+16) /* "" MSR SPEC_CTRL is implemented */
arch/x86/include/asm/nospec-branch.h +9 -7
index b222a3595946..956df82bbc2b 100644
@@ -115,7 +115,7 @@
 	ANNOTATE_NOSPEC_ALTERNATIVE
 	ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *\reg),	\
 		__stringify(RETPOLINE_JMP \reg), X86_FEATURE_RETPOLINE,	\
-		__stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *\reg), X86_FEATURE_RETPOLINE_AMD
+		__stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *\reg), X86_FEATURE_RETPOLINE_LFENCE
 #else
 	jmp	*\reg
 #endif
@@ -126,7 +126,7 @@
 	ANNOTATE_NOSPEC_ALTERNATIVE
 	ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; call *\reg),	\
 		__stringify(RETPOLINE_CALL \reg), X86_FEATURE_RETPOLINE,\
-		__stringify(lfence; ANNOTATE_RETPOLINE_SAFE; call *\reg), X86_FEATURE_RETPOLINE_AMD
+		__stringify(lfence; ANNOTATE_RETPOLINE_SAFE; call *\reg), X86_FEATURE_RETPOLINE_LFENCE
 #else
 	call	*\reg
 #endif
@@ -171,7 +171,7 @@
 	"lfence;\n"						\
 	ANNOTATE_RETPOLINE_SAFE					\
 	"call *%[thunk_target]\n",				\
-	X86_FEATURE_RETPOLINE_AMD)
+	X86_FEATURE_RETPOLINE_LFENCE)
 # define THUNK_TARGET(addr) [thunk_target] "r" (addr)
 
 #else /* CONFIG_X86_32 */
@@ -201,7 +201,7 @@
 	"lfence;\n"						\
 	ANNOTATE_RETPOLINE_SAFE					\
 	"call *%[thunk_target]\n",				\
-	X86_FEATURE_RETPOLINE_AMD)
+	X86_FEATURE_RETPOLINE_LFENCE)
 
 # define THUNK_TARGET(addr) [thunk_target] "rm" (addr)
 #endif
@@ -213,9 +213,11 @@
 /* The Spectre V2 mitigation variants */
 enum spectre_v2_mitigation {
 	SPECTRE_V2_NONE,
-	SPECTRE_V2_RETPOLINE_GENERIC,
-	SPECTRE_V2_RETPOLINE_AMD,
-	SPECTRE_V2_IBRS_ENHANCED,
+	SPECTRE_V2_RETPOLINE,
+	SPECTRE_V2_LFENCE,
+	SPECTRE_V2_EIBRS,
+	SPECTRE_V2_EIBRS_RETPOLINE,
+	SPECTRE_V2_EIBRS_LFENCE,
 };
 
 /* The indirect branch speculation control variants */
arch/x86/kernel/cpu/bugs.c +156 -60

337 lines not on this page · raw message

drivers/acpi/ec.c +0 -10
index ce9a570f217a..e5b92958c299 100644
@@ -2002,16 +2002,6 @@ bool acpi_ec_dispatch_gpe(void)
 	if (acpi_any_gpe_status_set(first_ec->gpe))
 		return true;
 
-	/*
-	 * Cancel the SCI wakeup and process all pending events in case there
-	 * are any wakeup ones in there.
-	 *
-	 * Note that if any non-EC GPEs are active at this point, the SCI will
-	 * retrigger after the rearming in acpi_s2idle_wake(), so no events
-	 * should be missed by canceling the wakeup here.
-	 */
-	pm_system_cancel_wakeup();
-
 	/*
 	 * Dispatch the EC GPE in-band, but do not report wakeup in any case
 	 * to allow the caller to process events properly after that.
drivers/acpi/sleep.c +10 -4
index cd590b4793e0..b0e23e3fe0d5 100644
@@ -1003,13 +1003,19 @@ static bool acpi_s2idle_wake(void)
 		if (acpi_check_wakeup_handlers())
 			return true;
 
-		/*
-		 * Check non-EC GPE wakeups and if there are none, cancel the
-		 * SCI-related wakeup and dispatch the EC GPE.
-		 */
+		/* Check non-EC GPE wakeups and dispatch the EC GPE. */
 		if (acpi_ec_dispatch_gpe())
 			return true;
 
+		/*
+		 * Cancel the SCI wakeup and process all pending events in case
+		 * there are any wakeup ones in there.
+		 *
+		 * Note that if any non-EC GPEs are active at this point, the
+		 * SCI will retrigger after the rearming below, so no events
+		 * should be missed by canceling the wakeup here.
+		 */
+		pm_system_cancel_wakeup();
 		acpi_os_wait_events_complete();
 
 		/*
drivers/block/xen-blkfront.c +37 -26

147 lines not on this page · raw message

drivers/firmware/psci/psci.c +15 -0
index 84f4ff351c62..eb797081d159 100644
@@ -57,6 +57,21 @@ struct psci_operations psci_ops = {
 	.smccc_version = SMCCC_VERSION_1_0,
 };
 
+enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void)
+{
+	if (psci_ops.smccc_version < SMCCC_VERSION_1_1)
+		return SMCCC_CONDUIT_NONE;
+
+	switch (psci_ops.conduit) {
+	case PSCI_CONDUIT_SMC:
+		return SMCCC_CONDUIT_SMC;
+	case PSCI_CONDUIT_HVC:
+		return SMCCC_CONDUIT_HVC;
+	default:
+		return SMCCC_CONDUIT_NONE;
+	}
+}
+
 typedef unsigned long (psci_fn)(unsigned long, unsigned long,
 				unsigned long, unsigned long);
 static psci_fn *invoke_psci_fn;
drivers/net/xen-netfront.c +33 -21

118 lines not on this page · raw message

drivers/scsi/xen-scsifront.c +1 -2
index f0068e96a177..39e39869a1ad 100644
@@ -233,12 +233,11 @@ static void scsifront_gnttab_done(struct vscsifrnt_info *info,
 		return;
 
 	for (i = 0; i < shadow->nr_grants; i++) {
-		if (unlikely(gnttab_query_foreign_access(shadow->gref[i]))) {
+		if (unlikely(!gnttab_try_end_foreign_access(shadow->gref[i]))) {
 			shost_printk(KERN_ALERT, info->host, KBUILD_MODNAME
 				     "grant still in use by backend\n");
 			BUG();
 		}
-		gnttab_end_foreign_access(shadow->gref[i], 0, 0UL);
 	}
 
 	kfree(shadow->sg);
drivers/xen/gntalloc.c +7 -18
index 3fa40c723e8e..edb0acd0b832 100644
@@ -169,20 +169,14 @@ static int add_grefs(struct ioctl_gntalloc_alloc_gref *op,
 		__del_gref(gref);
 	}
 
-	/* It's possible for the target domain to map the just-allocated grant
-	 * references by blindly guessing their IDs; if this is done, then
-	 * __del_gref will leave them in the queue_gref list. They need to be
-	 * added to the global list so that we can free them when they are no
-	 * longer referenced.
-	 */
-	if (unlikely(!list_empty(&queue_gref)))
-		list_splice_tail(&queue_gref, &gref_list);
 	mutex_unlock(&gref_mutex);
 	return rc;
 }
 
 static void __del_gref(struct gntalloc_gref *gref)
 {
+	unsigned long addr;
+
 	if (gref->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) {
 		uint8_t *tmp = kmap(gref->page);
 		tmp[gref->notify.pgoff] = 0;
@@ -196,21 +190,16 @@ static void __del_gref(struct gntalloc_gref *gref)
 	gref->notify.flags = 0;
 
 	if (gref->gref_id) {
-		if (gnttab_query_foreign_access(gref->gref_id))
-			return;
-
-		if (!gnttab_end_foreign_access_ref(gref->gref_id, 0))
-			return;
-
-		gnttab_free_grant_reference(gref->gref_id);
+		if (gref->page) {
+			addr = (unsigned long)page_to_virt(gref->page);
+			gnttab_end_foreign_access(gref->gref_id, 0, addr);
+		} else
+			gnttab_free_grant_reference(gref->gref_id);
 	}
 
 	gref_size--;
 	list_del(&gref->next_gref);
 
-	if (gref->page)
-		__free_page(gref->page);
-
 	kfree(gref);
 }
 
drivers/xen/grant-table.c +39 -32

125 lines not on this page · raw message

drivers/xen/pvcalls-front.c +4 -4
index 57592a6b5c9e..91e52e05555e 100644
@@ -337,8 +337,8 @@ static void free_active_ring(struct sock_mapping *map)
 	if (!map->active.ring)
 		return;
 
-	free_pages((unsigned long)map->active.data.in,
-			map->active.ring->ring_order);
+	free_pages_exact(map->active.data.in,
+			 PAGE_SIZE << map->active.ring->ring_order);
 	free_page((unsigned long)map->active.ring);
 }
 
@@ -352,8 +352,8 @@ static int alloc_active_ring(struct sock_mapping *map)
 		goto out;
 
 	map->active.ring->ring_order = PVCALLS_RING_ORDER;
-	bytes = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
-					PVCALLS_RING_ORDER);
+	bytes = alloc_pages_exact(PAGE_SIZE << PVCALLS_RING_ORDER,
+				  GFP_KERNEL | __GFP_ZERO);
 	if (!bytes)
 		goto out;
 
drivers/xen/xenbus/xenbus_client.c +11 -13
index 81eddb8529ff..8739dd0ee870 100644
@@ -366,7 +366,14 @@ int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
 		      unsigned int nr_pages, grant_ref_t *grefs)
 {
 	int err;
-	int i, j;
+	unsigned int i;
+	grant_ref_t gref_head;
+
+	err = gnttab_alloc_grant_references(nr_pages, &gref_head);
+	if (err) {
+		xenbus_dev_fatal(dev, err, "granting access to ring page");
+		return err;
+	}
 
 	for (i = 0; i < nr_pages; i++) {
 		unsigned long gfn;
@@ -376,23 +383,14 @@ int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
 		else
 			gfn = virt_to_gfn(vaddr);
 
-		err = gnttab_grant_foreign_access(dev->otherend_id, gfn, 0);
-		if (err < 0) {
-			xenbus_dev_fatal(dev, err,
-					 "granting access to ring page");
-			goto fail;
-		}
-		grefs[i] = err;
+		grefs[i] = gnttab_claim_grant_reference(&gref_head);
+		gnttab_grant_foreign_access_ref(grefs[i], dev->otherend_id,
+						gfn, 0);
 
 		vaddr = vaddr + XEN_PAGE_SIZE;
 	}
 
 	return 0;
-
-fail:
-	for (j = 0; j < i; j++)
-		gnttab_end_foreign_access_ref(grefs[j], 0);
-	return err;
 }
 EXPORT_SYMBOL_GPL(xenbus_grant_ring);
 
include/linux/arm-smccc.h +74 -0

85 lines not on this page · raw message

include/linux/bpf.h +12 -0
index 66590ae89c97..a73ca7c9c7d0 100644
@@ -751,6 +751,12 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
 int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
 				     const union bpf_attr *kattr,
 				     union bpf_attr __user *uattr);
+
+static inline bool unprivileged_ebpf_enabled(void)
+{
+	return !sysctl_unprivileged_bpf_disabled;
+}
+
 #else /* !CONFIG_BPF_SYSCALL */
 static inline struct bpf_prog *bpf_prog_get(u32 ufd)
 {
@@ -881,6 +887,12 @@ static inline int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
 {
 	return -ENOTSUPP;
 }
+
+static inline bool unprivileged_ebpf_enabled(void)
+{
+	return false;
+}
+
 #endif /* CONFIG_BPF_SYSCALL */
 
 static inline struct bpf_prog *bpf_prog_get_type(u32 ufd,
include/xen/grant_table.h +17 -2
index a9978350b45b..a58a89cc0e97 100644
@@ -97,17 +97,32 @@ int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly);
  * access has been ended, free the given page too.  Access will be ended
  * immediately iff the grant entry is not in use, otherwise it will happen
  * some time later.  page may be 0, in which case no freeing will occur.
+ * Note that the granted page might still be accessed (read or write) by the
+ * other side after gnttab_end_foreign_access() returns, so even if page was
+ * specified as 0 it is not allowed to just reuse the page for other
+ * purposes immediately. gnttab_end_foreign_access() will take an additional
+ * reference to the granted page in this case, which is dropped only after
+ * the grant is no longer in use.
+ * This requires that multi page allocations for areas subject to
+ * gnttab_end_foreign_access() are done via alloc_pages_exact() (and freeing
+ * via free_pages_exact()) in order to avoid high order pages.
  */
 void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
 			       unsigned long page);
 
+/*
+ * End access through the given grant reference, iff the grant entry is
+ * no longer in use.  In case of success ending foreign access, the
+ * grant reference is deallocated.
+ * Return 1 if the grant entry was freed, 0 if it is still in use.
+ */
+int gnttab_try_end_foreign_access(grant_ref_t ref);
+
 int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn);
 
 unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref);
 unsigned long gnttab_end_foreign_transfer(grant_ref_t ref);
 
-int gnttab_query_foreign_access(grant_ref_t ref);
-
 /*
  * operations on reserved batches of grant references
  */
kernel/sysctl.c +8 -0
index 8494d5a706bb..0457d36540e3 100644
@@ -251,6 +251,11 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
 #endif
 
 #ifdef CONFIG_BPF_SYSCALL
+
+void __weak unpriv_ebpf_notify(int new_state)
+{
+}
+
 static int bpf_unpriv_handler(struct ctl_table *table, int write,
                              void *buffer, size_t *lenp, loff_t *ppos)
 {
@@ -268,6 +273,9 @@ static int bpf_unpriv_handler(struct ctl_table *table, int write,
 			return -EPERM;
 		*(int *)table->data = unpriv_enable;
 	}
+
+	unpriv_ebpf_notify(unpriv_enable);
+
 	return ret;
 }
 #endif
net/9p/trans_xen.c +6 -8
index 44e6c74ed428..2779ec1053a0 100644
@@ -301,9 +301,9 @@ static void xen_9pfs_front_free(struct xen_9pfs_front_priv *priv)
 				ref = priv->rings[i].intf->ref[j];
 				gnttab_end_foreign_access(ref, 0, 0);
 			}
-			free_pages((unsigned long)priv->rings[i].data.in,
-				   XEN_9PFS_RING_ORDER -
-				   (PAGE_SHIFT - XEN_PAGE_SHIFT));
+			free_pages_exact(priv->rings[i].data.in,
+				   1UL << (XEN_9PFS_RING_ORDER +
+					   XEN_PAGE_SHIFT));
 		}
 		gnttab_end_foreign_access(priv->rings[i].ref, 0, 0);
 		free_page((unsigned long)priv->rings[i].intf);
@@ -341,8 +341,8 @@ static int xen_9pfs_front_alloc_dataring(struct xenbus_device *dev,
 	if (ret < 0)
 		goto out;
 	ring->ref = ret;
-	bytes = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
-			XEN_9PFS_RING_ORDER - (PAGE_SHIFT - XEN_PAGE_SHIFT));
+	bytes = alloc_pages_exact(1UL << (XEN_9PFS_RING_ORDER + XEN_PAGE_SHIFT),
+				  GFP_KERNEL | __GFP_ZERO);
 	if (!bytes) {
 		ret = -ENOMEM;
 		goto out;
@@ -373,9 +373,7 @@ static int xen_9pfs_front_alloc_dataring(struct xenbus_device *dev,
 	if (bytes) {
 		for (i--; i >= 0; i--)
 			gnttab_end_foreign_access(ring->intf->ref[i], 0, 0);
-		free_pages((unsigned long)bytes,
-			   XEN_9PFS_RING_ORDER -
-			   (PAGE_SHIFT - XEN_PAGE_SHIFT));
+		free_pages_exact(bytes, 1UL << (XEN_9PFS_RING_ORDER + XEN_PAGE_SHIFT));
 	}
 	gnttab_end_foreign_access(ring->ref, 0, 0);
 	free_page((unsigned long)ring->intf);
tools/arch/x86/include/asm/cpufeatures.h +1 -1
index 0652d3eed9bd..4133c721af6e 100644
@@ -202,7 +202,7 @@
 #define X86_FEATURE_SME			( 7*32+10) /* AMD Secure Memory Encryption */
 #define X86_FEATURE_PTI			( 7*32+11) /* Kernel Page Table Isolation enabled */
 #define X86_FEATURE_RETPOLINE		( 7*32+12) /* "" Generic Retpoline mitigation for Spectre variant 2 */
-#define X86_FEATURE_RETPOLINE_AMD	( 7*32+13) /* "" AMD Retpoline mitigation for Spectre variant 2 */
+#define X86_FEATURE_RETPOLINE_LFENCE	( 7*32+13) /* "" Use LFENCEs for Spectre variant 2 */
 #define X86_FEATURE_INTEL_PPIN		( 7*32+14) /* Intel Processor Inventory Number */
 #define X86_FEATURE_CDP_L2		( 7*32+15) /* Code and Data Prioritization L2 */
 #define X86_FEATURE_MSR_SPEC_CTRL	( 7*32+16) /* "" MSR SPEC_CTRL is implemented */