commit 8618ddd817621c40c1f44f0ab6df7c7805234416

Author: Dave Anderson <anderson@redhat.com>

Date:   Fri Feb 1 15:01:29 2019 -0500

    First phase of support for ARM64 kernels that are configured with

    CONFIG_ARM64_USER_VA_BITS_52, which causes the PTRS_PER_PGD count

    to increase from 64 to 1024.  Without the patch, "WARNING: cannot

    access vmalloc'd module memory" will be displayed during session

    initialization, and the translation of any mapped kernel virtual

    address that requires a page table walk will fail, leading to a

    myriad of other errors.

    (anderson@redhat.com)

diff --git a/arm64.c b/arm64.c

index 45c7313..2308612 100644

--- a/arm64.c

+++ b/arm64.c

@@ -1,8 +1,8 @@

 /*

  * arm64.c - core analysis suite

  *

- * Copyright (C) 2012-2018 David Anderson

- * Copyright (C) 2012-2018 Red Hat, Inc. All rights reserved.

+ * Copyright (C) 2012-2019 David Anderson

+ * Copyright (C) 2012-2019 Red Hat, Inc. All rights reserved.

  *

  * This program is free software; you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

@@ -209,6 +209,8 @@ arm64_init(int when)

 		ms->page_offset = ARM64_PAGE_OFFSET;

 		machdep->identity_map_base = ARM64_PAGE_OFFSET;

 		machdep->kvbase = ARM64_VA_START;

+		machdep->is_kvaddr = generic_is_kvaddr;

+		machdep->kvtop = arm64_kvtop;

 		ms->userspace_top = ARM64_USERSPACE_TOP;

 		if (machdep->flags & NEW_VMEMMAP) {

 			struct syment *sp;

@@ -262,11 +264,17 @@ arm64_init(int when)

 			break;

 		case 65536:

+			if (kernel_symbol_exists("idmap_ptrs_per_pgd") &&

+			    readmem(symbol_value("idmap_ptrs_per_pgd"), KVADDR,

+			    &value, sizeof(ulong), "idmap_ptrs_per_pgd", RETURN_ON_ERROR))

+				machdep->ptrs_per_pgd = value;

+		

 			if (machdep->machspec->VA_BITS > PGDIR_SHIFT_L3_64K) {

 				machdep->flags |= VM_L3_64K;

-				machdep->ptrs_per_pgd = PTRS_PER_PGD_L3_64K;

+				if (!machdep->ptrs_per_pgd)

+					machdep->ptrs_per_pgd = PTRS_PER_PGD_L3_64K;

 				if ((machdep->pgd =

-				    (char *)malloc(PTRS_PER_PGD_L3_64K * 8)) == NULL)

+				    (char *)malloc(machdep->ptrs_per_pgd * 8)) == NULL)

 					error(FATAL, "cannot malloc pgd space.");

 				if ((machdep->pmd =

 				    (char *)malloc(PTRS_PER_PMD_L3_64K * 8)) == NULL)

@@ -276,9 +284,10 @@ arm64_init(int when)

 					error(FATAL, "cannot malloc ptbl space.");

 			} else {

 				machdep->flags |= VM_L2_64K;

-				machdep->ptrs_per_pgd = PTRS_PER_PGD_L2_64K;

+				if (!machdep->ptrs_per_pgd)

+					machdep->ptrs_per_pgd = PTRS_PER_PGD_L2_64K;

 				if ((machdep->pgd =

-				    (char *)malloc(PTRS_PER_PGD_L2_64K * 8)) == NULL)

+				    (char *)malloc(machdep->ptrs_per_pgd * 8)) == NULL)

 					error(FATAL, "cannot malloc pgd space.");

 				if ((machdep->ptbl =

 				    (char *)malloc(PTRS_PER_PTE_L2_64K * 8)) == NULL)

@@ -306,9 +315,11 @@ arm64_init(int when)

 		machdep->flags |= VMEMMAP;

 		machdep->uvtop = arm64_uvtop;

-		machdep->kvtop = arm64_kvtop;

-		machdep->is_kvaddr = generic_is_kvaddr;

 		machdep->is_uvaddr = arm64_is_uvaddr;

+		if (kernel_symbol_exists("vabits_user") && 

+		    readmem(symbol_value("vabits_user"), KVADDR,

+		    &value, sizeof(ulong), "vabits_user", RETURN_ON_ERROR))

+			machdep->machspec->vabits_user = value;

 		machdep->eframe_search = arm64_eframe_search;

 		machdep->back_trace = arm64_back_trace_cmd;

 		machdep->in_alternate_stack = arm64_in_alternate_stack;

@@ -350,10 +361,14 @@ arm64_init(int when)

 	case POST_GDB:

 		arm64_calc_virtual_memory_ranges();

 		machdep->section_size_bits = _SECTION_SIZE_BITS;

-		if (THIS_KERNEL_VERSION >= LINUX(3,17,0))

-			machdep->max_physmem_bits = _MAX_PHYSMEM_BITS_3_17;

-		else

-			machdep->max_physmem_bits = _MAX_PHYSMEM_BITS;

+		if (!machdep->max_physmem_bits) {

+			if (machdep->machspec->VA_BITS == 52)  /* guess */

+				machdep->max_physmem_bits = _MAX_PHYSMEM_BITS_52;

+			else if (THIS_KERNEL_VERSION >= LINUX(3,17,0)) 

+				machdep->max_physmem_bits = _MAX_PHYSMEM_BITS_3_17;

+			else

+				machdep->max_physmem_bits = _MAX_PHYSMEM_BITS;

+		}

 		ms = machdep->machspec;

 		if (THIS_KERNEL_VERSION >= LINUX(4,0,0)) {

@@ -601,6 +616,11 @@ arm64_dump_machdep_table(ulong arg)

 	fprintf(fp, "            machspec: %lx\n", (ulong)ms);

 	fprintf(fp, "               VA_BITS: %ld\n", ms->VA_BITS);

+	fprintf(fp, "           vabits_user: ");

+	if (ms->vabits_user)

+		fprintf(fp, "%ld\n", ms->vabits_user);

+	else

+		fprintf(fp, "(unused)\n");

 	fprintf(fp, "         userspace_top: %016lx\n", ms->userspace_top);

 	fprintf(fp, "           page_offset: %016lx\n", ms->page_offset);

 	fprintf(fp, "    vmalloc_start_addr: %016lx\n", ms->vmalloc_start_addr);

@@ -691,6 +711,8 @@ arm64_parse_machdep_arg_l(char *argstring, char *param, ulong *value)

 			*value = dtol(p, flags, &err;;

 			if (!err)

 				*value = MEGABYTES(*value);

+		} else if (STRNEQ(argstring, "max_physmem_bits")) {

+			*value = dtol(p, flags, &err;;

 		} else {

 			*value = htol(p, flags, &err;;

 		}

@@ -750,6 +772,12 @@ arm64_parse_cmdline_args(void)

 					"setting kimage_voffset to: 0x%lx\n\n",

 					machdep->machspec->kimage_voffset);

 				continue;

+			} else if (arm64_parse_machdep_arg_l(arglist[i], "max_physmem_bits",

+			        &machdep->max_physmem_bits)) {

+				error(NOTE,

+					"setting max_physmem_bits to: %ld\n\n",

+					machdep->max_physmem_bits);

+				continue;

 			}

 			error(WARNING, "ignoring --machdep option: %s\n",

@@ -1065,8 +1093,8 @@ arm64_vtop_2level_64k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose)

                 fprintf(fp, "PAGE DIRECTORY: %lx\n", pgd);

 	pgd_base = (ulong *)pgd;

-	FILL_PGD(pgd_base, KVADDR, PTRS_PER_PGD_L2_64K * sizeof(ulong));

-	pgd_ptr = pgd_base + (((vaddr) >> PGDIR_SHIFT_L2_64K) & (PTRS_PER_PGD_L2_64K - 1));

+	FILL_PGD(pgd_base, KVADDR, machdep->ptrs_per_pgd * sizeof(ulong));

+	pgd_ptr = pgd_base + (((vaddr) >> PGDIR_SHIFT_L2_64K) & (machdep->ptrs_per_pgd - 1));

         pgd_val = ULONG(machdep->pgd + PAGEOFFSET(pgd_ptr));

         if (verbose) 

                 fprintf(fp, "   PGD: %lx => %lx\n", (ulong)pgd_ptr, pgd_val);

@@ -1129,8 +1157,8 @@ arm64_vtop_3level_64k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose)

                 fprintf(fp, "PAGE DIRECTORY: %lx\n", pgd);

 	pgd_base = (ulong *)pgd;

-	FILL_PGD(pgd_base, KVADDR, PTRS_PER_PGD_L3_64K * sizeof(ulong));

-	pgd_ptr = pgd_base + (((vaddr) >> PGDIR_SHIFT_L3_64K) & (PTRS_PER_PGD_L3_64K - 1));

+	FILL_PGD(pgd_base, KVADDR, machdep->ptrs_per_pgd * sizeof(ulong));

+	pgd_ptr = pgd_base + (((vaddr) >> PGDIR_SHIFT_L3_64K) & (machdep->ptrs_per_pgd - 1));

         pgd_val = ULONG(machdep->pgd + PGDIR_OFFSET_L3_64K(pgd_ptr));

         if (verbose)

                 fprintf(fp, "   PGD: %lx => %lx\n", (ulong)pgd_ptr, pgd_val);

diff --git a/crash.8 b/crash.8

index 8c11615..f9de36d 100644

--- a/crash.8

+++ b/crash.8

@@ -278,6 +278,7 @@ ARM:

 ARM64:  

   phys_offset=<physical-address>

   kimage_voffset=<kimage_voffset-value>

+  max_physmem_bits=<value>

 X86:

   page_offset=<CONFIG_PAGE_OFFSET-value>

 .fi

diff --git a/defs.h b/defs.h

index b473972..05f2d17 100644

--- a/defs.h

+++ b/defs.h

@@ -3049,7 +3049,7 @@ typedef signed int s32;

 #define PMD_SHIFT_L3_64K     (29)

 #define PMD_SIZE_L3_64K      (1UL << PMD_SHIFT_L3_64K)

 #define PMD_MASK_L3_64K      (~(PMD_SIZE_L3_64K-1))

-#define PGDIR_OFFSET_L3_64K(X) (((ulong)(X)) & ((PTRS_PER_PGD_L3_64K * 8) - 1))

+#define PGDIR_OFFSET_L3_64K(X) (((ulong)(X)) & ((machdep->ptrs_per_pgd * 8) - 1))

 /*

  * 2-levels / 64K pages

@@ -3136,6 +3136,7 @@ typedef signed int s32;

 #define _SECTION_SIZE_BITS      30

 #define _MAX_PHYSMEM_BITS       40

 #define _MAX_PHYSMEM_BITS_3_17  48

+#define _MAX_PHYSMEM_BITS_52    52

 typedef unsigned long long __u64;

 typedef unsigned long long u64;

@@ -3215,6 +3216,7 @@ struct machine_specific {

 	ulong kern_eframe_offset;

 	ulong machine_kexec_start;

 	ulong machine_kexec_end;

+	ulong vabits_user;

 };

 struct arm64_stackframe {

diff --git a/help.c b/help.c

index ff0c80b..ba15dec 100644

--- a/help.c

+++ b/help.c

@@ -179,6 +179,7 @@ char *program_usage_info[] = {

     "    ARM64:",

     "      phys_offset=<physical-address>",

     "      kimage_voffset=<kimage_voffset-value>",

+    "      max_physmem_bits=<value>",

     "    X86:",

     "      page_offset=<CONFIG_PAGE_OFFSET-value>",

     "",