Merge tag 'v5.4.79' into linux-5.4-at91

This is the 5.4.79 stable release

Author: noglitch

Documentation/admin-guide/kernel-parameters.txt

@@ -2667,6 +2667,8 @@
 					       mds=off [X86]
 					       tsx_async_abort=off [X86]
 					       kvm.nx_huge_pages=off [X86]
+					       no_entry_flush [PPC]
+					       no_uaccess_flush [PPC]
 
 				Exceptions:
 					       This does not have any effect on
@@ -2989,6 +2991,8 @@
 
 	noefi		Disable EFI runtime services support.
 
+	no_entry_flush  [PPC] Don't flush the L1-D cache when entering the kernel.
+
 	noexec		[IA-64]
 
 	noexec		[X86]
@@ -3038,6 +3042,9 @@
 	nospec_store_bypass_disable
 			[HW] Disable all mitigations for the Speculative Store Bypass vulnerability
 
+	no_uaccess_flush
+	                [PPC] Don't flush the L1-D cache after accessing user data.
+
 	noxsave		[BUGS=X86] Disables x86 extended register state save
 			and restore using xsave. The kernel will fallback to
 			enabling legacy floating-point and sse state.

Makefile

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 VERSION = 5
 PATCHLEVEL = 4
-SUBLEVEL = 78
+SUBLEVEL = 79
 EXTRAVERSION = -linux4sam-2020.10-rc3
 NAME = Kleptomaniac Octopus
 

arch/mips/pci/pci-xtalk-bridge.c

@@ -284,7 +284,7 @@ static int bridge_set_affinity(struct irq_data *d, const struct cpumask *mask,
 	ret = irq_chip_set_affinity_parent(d, mask, force);
 	if (ret >= 0) {
 		cpu = cpumask_first_and(mask, cpu_online_mask);
-		data->nnasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu));
+		data->nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu));
 		bridge_write(data->bc, b_int_addr[pin].addr,
 			     (((data->bc->intr_addr >> 30) & 0x30000) |
 			      bit | (data->nasid << 8)));

arch/powerpc/include/asm/book3s/64/kup-radix.h

@@ -11,13 +11,12 @@
 
 #ifdef __ASSEMBLY__
 
-.macro kuap_restore_amr	gpr
 #ifdef CONFIG_PPC_KUAP
+.macro kuap_restore_amr	gpr
 	BEGIN_MMU_FTR_SECTION_NESTED(67)
 	ld	\gpr, STACK_REGS_KUAP(r1)
 	mtspr	SPRN_AMR, \gpr
 	END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_RADIX_KUAP, 67)
-#endif
 .endm
 
 .macro kuap_check_amr gpr1, gpr2
@@ -31,6 +30,7 @@
 	END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_RADIX_KUAP, 67)
 #endif
 .endm
+#endif
 
 .macro kuap_save_amr_and_lock gpr1, gpr2, use_cr, msr_pr_cr
 #ifdef CONFIG_PPC_KUAP
@@ -54,6 +54,8 @@
 
 #else /* !__ASSEMBLY__ */
 
+DECLARE_STATIC_KEY_FALSE(uaccess_flush_key);
+
 #ifdef CONFIG_PPC_KUAP
 
 #include <asm/reg.h>
@@ -77,6 +79,18 @@ static inline void set_kuap(unsigned long value)
 	isync();
 }
 
+static inline bool
+bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+{
+	return WARN(mmu_has_feature(MMU_FTR_RADIX_KUAP) &&
+		    (regs->kuap & (is_write ? AMR_KUAP_BLOCK_WRITE : AMR_KUAP_BLOCK_READ)),
+		    "Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read");
+}
+#else /* CONFIG_PPC_KUAP */
+static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr) { }
+static inline void set_kuap(unsigned long value) { }
+#endif /* !CONFIG_PPC_KUAP */
+
 static __always_inline void allow_user_access(void __user *to, const void __user *from,
 					      unsigned long size, unsigned long dir)
 {
@@ -94,17 +108,10 @@ static inline void prevent_user_access(void __user *to, const void __user *from,
 				       unsigned long size, unsigned long dir)
 {
 	set_kuap(AMR_KUAP_BLOCKED);
+	if (static_branch_unlikely(&uaccess_flush_key))
+		do_uaccess_flush();
 }
 
-static inline bool
-bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
-{
-	return WARN(mmu_has_feature(MMU_FTR_RADIX_KUAP) &&
-		    (regs->kuap & (is_write ? AMR_KUAP_BLOCK_WRITE : AMR_KUAP_BLOCK_READ)),
-		    "Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read");
-}
-#endif /* CONFIG_PPC_KUAP */
-
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_BOOK3S_64_KUP_RADIX_H */

arch/powerpc/include/asm/exception-64s.h

@@ -61,11 +61,18 @@
 	nop;								\
 	nop
 
+#define ENTRY_FLUSH_SLOT						\
+	ENTRY_FLUSH_FIXUP_SECTION;					\
+	nop;								\
+	nop;								\
+	nop;
+
 /*
  * r10 must be free to use, r13 must be paca
  */
 #define INTERRUPT_TO_KERNEL						\
-	STF_ENTRY_BARRIER_SLOT
+	STF_ENTRY_BARRIER_SLOT;						\
+	ENTRY_FLUSH_SLOT
 
 /*
  * Macros for annotating the expected destination of (h)rfid
@@ -127,6 +134,9 @@
 	hrfid;								\
 	b	hrfi_flush_fallback
 
+#else /* __ASSEMBLY__ */
+/* Prototype for function defined in exceptions-64s.S */
+void do_uaccess_flush(void);
 #endif /* __ASSEMBLY__ */
 
 #endif	/* _ASM_POWERPC_EXCEPTION_H */

arch/powerpc/include/asm/feature-fixups.h

@@ -205,6 +205,22 @@ label##3:					       	\
 	FTR_ENTRY_OFFSET 955b-956b;			\
 	.popsection;
 
+#define UACCESS_FLUSH_FIXUP_SECTION			\
+959:							\
+	.pushsection __uaccess_flush_fixup,"a";		\
+	.align 2;					\
+960:							\
+	FTR_ENTRY_OFFSET 959b-960b;			\
+	.popsection;
+
+#define ENTRY_FLUSH_FIXUP_SECTION			\
+957:							\
+	.pushsection __entry_flush_fixup,"a";		\
+	.align 2;					\
+958:							\
+	FTR_ENTRY_OFFSET 957b-958b;			\
+	.popsection;
+
 #define RFI_FLUSH_FIXUP_SECTION				\
 951:							\
 	.pushsection __rfi_flush_fixup,"a";		\
@@ -237,8 +253,11 @@ label##3:					       	\
 #include <linux/types.h>
 
 extern long stf_barrier_fallback;
+extern long entry_flush_fallback;
 extern long __start___stf_entry_barrier_fixup, __stop___stf_entry_barrier_fixup;
 extern long __start___stf_exit_barrier_fixup, __stop___stf_exit_barrier_fixup;
+extern long __start___uaccess_flush_fixup, __stop___uaccess_flush_fixup;
+extern long __start___entry_flush_fixup, __stop___entry_flush_fixup;
 extern long __start___rfi_flush_fixup, __stop___rfi_flush_fixup;
 extern long __start___barrier_nospec_fixup, __stop___barrier_nospec_fixup;
 extern long __start__btb_flush_fixup, __stop__btb_flush_fixup;

arch/powerpc/include/asm/kup.h

@@ -6,7 +6,7 @@
 #define KUAP_WRITE	2
 #define KUAP_READ_WRITE	(KUAP_READ | KUAP_WRITE)
 
-#ifdef CONFIG_PPC64
+#ifdef CONFIG_PPC_BOOK3S_64
 #include <asm/book3s/64/kup-radix.h>
 #endif
 #ifdef CONFIG_PPC_8xx
@@ -24,9 +24,15 @@
 .macro kuap_restore	sp, current, gpr1, gpr2, gpr3
 .endm
 
+.macro kuap_restore_amr gpr
+.endm
+
 .macro kuap_check	current, gpr
 .endm
 
+.macro kuap_check_amr	gpr1, gpr2
+.endm
+
 #endif
 
 #else /* !__ASSEMBLY__ */
@@ -45,15 +51,26 @@ static inline void setup_kuep(bool disabled) { }
 void setup_kuap(bool disabled);
 #else
 static inline void setup_kuap(bool disabled) { }
-static inline void allow_user_access(void __user *to, const void __user *from,
-				     unsigned long size, unsigned long dir) { }
-static inline void prevent_user_access(void __user *to, const void __user *from,
-				       unsigned long size, unsigned long dir) { }
+
 static inline bool
 bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
 	return false;
 }
+
+static inline void kuap_check_amr(void) { }
+
+/*
+ * book3s/64/kup-radix.h defines these functions for the !KUAP case to flush
+ * the L1D cache after user accesses. Only include the empty stubs for other
+ * platforms.
+ */
+#ifndef CONFIG_PPC_BOOK3S_64
+static inline void allow_user_access(void __user *to, const void __user *from,
+				     unsigned long size, unsigned long dir) { }
+static inline void prevent_user_access(void __user *to, const void __user *from,
+				       unsigned long size, unsigned long dir) { }
+#endif /* CONFIG_PPC_BOOK3S_64 */
 #endif /* CONFIG_PPC_KUAP */
 
 static inline void allow_read_from_user(const void __user *from, unsigned long size)

arch/powerpc/include/asm/security_features.h

@@ -84,12 +84,19 @@ static inline bool security_ftr_enabled(u64 feature)
 // Software required to flush link stack on context switch
 #define SEC_FTR_FLUSH_LINK_STACK	0x0000000000001000ull
 
+// The L1-D cache should be flushed when entering the kernel
+#define SEC_FTR_L1D_FLUSH_ENTRY		0x0000000000004000ull
+
+// The L1-D cache should be flushed after user accesses from the kernel
+#define SEC_FTR_L1D_FLUSH_UACCESS	0x0000000000008000ull
 
 // Features enabled by default
 #define SEC_FTR_DEFAULT \
 	(SEC_FTR_L1D_FLUSH_HV | \
 	 SEC_FTR_L1D_FLUSH_PR | \
 	 SEC_FTR_BNDS_CHK_SPEC_BAR | \
+	 SEC_FTR_L1D_FLUSH_ENTRY | \
+	 SEC_FTR_L1D_FLUSH_UACCESS | \
 	 SEC_FTR_FAVOUR_SECURITY)
 
 #endif /* _ASM_POWERPC_SECURITY_FEATURES_H */

arch/powerpc/include/asm/setup.h

@@ -52,12 +52,16 @@ enum l1d_flush_type {
 };
 
 void setup_rfi_flush(enum l1d_flush_type, bool enable);
+void setup_entry_flush(bool enable);
+void setup_uaccess_flush(bool enable);
 void do_rfi_flush_fixups(enum l1d_flush_type types);
 #ifdef CONFIG_PPC_BARRIER_NOSPEC
 void setup_barrier_nospec(void);
 #else
 static inline void setup_barrier_nospec(void) { };
 #endif
+void do_uaccess_flush_fixups(enum l1d_flush_type types);
+void do_entry_flush_fixups(enum l1d_flush_type types);
 void do_barrier_nospec_fixups(bool enable);
 extern bool barrier_nospec_enabled;