Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:

 - Fix Kconfig dependencies to re-allow the enabling of function graph
   tracer and shadow call stacks at the same time.

 - Revert the workaround for CPU erratum #2645198 since the CONFIG_
   guards were incorrect and the code has therefore not seen any real
   exposure in -next.

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  Revert "arm64: errata: Workaround possible Cortex-A715 [ESR|FAR]_ELx corruption"
  ftrace: Allow WITH_ARGS flavour of graph tracer with shadow call stack

Documentation/arm64/silicon-errata.rst

@@ -120,8 +120,6 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-A710     | #2224489        | ARM64_ERRATUM_2224489       |
 +----------------+-----------------+-----------------+-----------------------------+
-| ARM            | Cortex-A715     | #2645198        | ARM64_ERRATUM_2645198       |
-+----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-X2       | #2119858        | ARM64_ERRATUM_2119858       |
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-X2       | #2224489        | ARM64_ERRATUM_2224489       |

arch/Kconfig

@@ -638,7 +638,7 @@ config ARCH_SUPPORTS_SHADOW_CALL_STACK
 config SHADOW_CALL_STACK
 	bool "Shadow Call Stack"
 	depends on ARCH_SUPPORTS_SHADOW_CALL_STACK
-	depends on DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER
+	depends on DYNAMIC_FTRACE_WITH_ARGS || DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER
 	help
 	  This option enables the compiler's Shadow Call Stack, which
 	  uses a shadow stack to protect function return addresses from

arch/arm64/Kconfig

@@ -972,22 +972,6 @@ config ARM64_ERRATUM_2457168
 
 	  If unsure, say Y.
 
-config ARM64_ERRATUM_2645198
-	bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
-	default y
-	help
-	  This option adds the workaround for ARM Cortex-A715 erratum 2645198.
-
-	  If a Cortex-A715 cpu sees a page mapping permissions change from executable
-	  to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
-	  next instruction abort caused by permission fault.
-
-	  Only user-space does executable to non-executable permission transition via
-	  mprotect() system call. Workaround the problem by doing a break-before-make
-	  TLB invalidation, for all changes to executable user space mappings.
-
-	  If unsure, say Y.
-
 config CAVIUM_ERRATUM_22375
 	bool "Cavium erratum 22375, 24313"
 	default y

arch/arm64/include/asm/hugetlb.h

@@ -49,15 +49,6 @@ extern pte_t huge_ptep_get(pte_t *ptep);
 
 void __init arm64_hugetlb_cma_reserve(void);
 
-#define huge_ptep_modify_prot_start huge_ptep_modify_prot_start
-extern pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
-					 unsigned long addr, pte_t *ptep);
-
-#define huge_ptep_modify_prot_commit huge_ptep_modify_prot_commit
-extern void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
-					 unsigned long addr, pte_t *ptep,
-					 pte_t old_pte, pte_t new_pte);
-
 #include <asm-generic/hugetlb.h>
 
 #endif /* __ASM_HUGETLB_H */

arch/arm64/include/asm/pgtable.h

@@ -1093,15 +1093,6 @@ static inline bool pud_sect_supported(void)
 }
 
 
-#define __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
-#define ptep_modify_prot_start ptep_modify_prot_start
-extern pte_t ptep_modify_prot_start(struct vm_area_struct *vma,
-				    unsigned long addr, pte_t *ptep);
-
-#define ptep_modify_prot_commit ptep_modify_prot_commit
-extern void ptep_modify_prot_commit(struct vm_area_struct *vma,
-				    unsigned long addr, pte_t *ptep,
-				    pte_t old_pte, pte_t new_pte);
 #endif /* !__ASSEMBLY__ */
 
 #endif /* __ASM_PGTABLE_H */

arch/arm64/kernel/cpu_errata.c

@@ -661,13 +661,6 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 		CAP_MIDR_RANGE_LIST(trbe_write_out_of_range_cpus),
 	},
 #endif
-#ifdef CONFIG_ARM64_ERRATUM_2645198
-	{
-		.desc = "ARM erratum 2645198",
-		.capability = ARM64_WORKAROUND_2645198,
-		ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A715)
-	},
-#endif
 #ifdef CONFIG_ARM64_ERRATUM_2077057
 	{
 		.desc = "ARM erratum 2077057",

arch/arm64/mm/hugetlbpage.c

@@ -559,24 +559,3 @@ bool __init arch_hugetlb_valid_size(unsigned long size)
 {
 	return __hugetlb_valid_size(size);
 }
-
-pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
-{
-	if (IS_ENABLED(CONFIG_ARM64_WORKAROUND_2645198) &&
-	    cpus_have_const_cap(ARM64_WORKAROUND_2645198)) {
-		/*
-		 * Break-before-make (BBM) is required for all user space mappings
-		 * when the permission changes from executable to non-executable
-		 * in cases where cpu is affected with errata #2645198.
-		 */
-		if (pte_user_exec(READ_ONCE(*ptep)))
-			return huge_ptep_clear_flush(vma, addr, ptep);
-	}
-	return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
-}
-
-void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep,
-				  pte_t old_pte, pte_t pte)
-{
-	set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
-}

arch/arm64/mm/mmu.c

@@ -1630,24 +1630,3 @@ static int __init prevent_bootmem_remove_init(void)
 }
 early_initcall(prevent_bootmem_remove_init);
 #endif
-
-pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
-{
-	if (IS_ENABLED(CONFIG_ARM64_WORKAROUND_2645198) &&
-	    cpus_have_const_cap(ARM64_WORKAROUND_2645198)) {
-		/*
-		 * Break-before-make (BBM) is required for all user space mappings
-		 * when the permission changes from executable to non-executable
-		 * in cases where cpu is affected with errata #2645198.
-		 */
-		if (pte_user_exec(READ_ONCE(*ptep)))
-			return ptep_clear_flush(vma, addr, ptep);
-	}
-	return ptep_get_and_clear(vma->vm_mm, addr, ptep);
-}
-
-void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep,
-			     pte_t old_pte, pte_t pte)
-{
-	set_pte_at(vma->vm_mm, addr, ptep, pte);
-}

arch/arm64/tools/cpucaps

@@ -71,7 +71,6 @@ WORKAROUND_2038923
 WORKAROUND_2064142
 WORKAROUND_2077057
 WORKAROUND_2457168
-WORKAROUND_2645198
 WORKAROUND_2658417
 WORKAROUND_TRBE_OVERWRITE_FILL_MODE
 WORKAROUND_TSB_FLUSH_FAILURE