svn commit: r360277 - head/sys/arm64/arm64

[Mark Johnston]

Author: markj
Date: Fri Apr 24 18:47:57 2020
New Revision: 360277
URL: https://svnweb.freebsd.org/changeset/base/360277

Log:
  Fix handling of 1GB mappings in the arm64 minidump code.
  
  For such mappings we need to dump 512 page table pages, not one, and
  they need to be included in the pmap size recorded in the minidump
  header.
  
  MFC after:	2 weeks
  Sponsored by:	Juniper Networks, Klara Inc.

Modified:
  head/sys/arm64/arm64/minidump_machdep.c

Modified: head/sys/arm64/arm64/minidump_machdep.c
==============================================================================
--- head/sys/arm64/arm64/minidump_machdep.c	Fri Apr 24 18:47:42 2020	(r360276)
+++ head/sys/arm64/arm64/minidump_machdep.c	Fri Apr 24 18:47:57 2020	(r360277)
@@ -34,8 +34,6 @@ __FBSDID("$FreeBSD$");
 
 #include "opt_watchdog.h"
 
-#include "opt_watchdog.h"
-
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/conf.h>
@@ -68,7 +66,7 @@ static size_t fragsz;
 static void *dump_va;
 static size_t counter, progress, dumpsize;
 
-static uint64_t tmpbuffer[PAGE_SIZE / sizeof(uint64_t)];
+static uint64_t tmpbuffer[Ln_ENTRIES];
 
 CTASSERT(sizeof(*vm_page_dump) == 8);
 
@@ -210,16 +208,14 @@ blk_write(struct dumperinfo *di, char *ptr, vm_paddr_t
 int
 minidumpsys(struct dumperinfo *di)
 {
+	struct minidumphdr mdhdr;
 	pd_entry_t *l0, *l1, *l2;
 	pt_entry_t *l3;
-	uint32_t pmapsize;
 	vm_offset_t va;
 	vm_paddr_t pa;
-	int error;
 	uint64_t bits;
-	int i, bit;
-	int retry_count;
-	struct minidumphdr mdhdr;
+	uint32_t pmapsize;
+	int bit, error, i, j, retry_count;
 
 	retry_count = 0;
  retry:
@@ -231,11 +227,15 @@ minidumpsys(struct dumperinfo *di)
 		if (!pmap_get_tables(pmap_kernel(), va, &l0, &l1, &l2, &l3))
 			continue;
 
-		/* We should always be using the l2 table for kvm */
-		if (l2 == NULL)
-			continue;
-
-		if ((*l2 & ATTR_DESCR_MASK) == L2_BLOCK) {
+		if ((*l1 & ATTR_DESCR_MASK) == L1_BLOCK) {
+			pa = *l1 & ~ATTR_MASK;
+			for (i = 0; i < Ln_ENTRIES * Ln_ENTRIES;
+			    i++, pa += PAGE_SIZE)
+				if (is_dumpable(pa))
+					dump_add_page(pa);
+			pmapsize += (Ln_ENTRIES - 1) * PAGE_SIZE;
+			va += L1_SIZE - L2_SIZE;
+		} else if ((*l2 & ATTR_DESCR_MASK) == L2_BLOCK) {
 			pa = *l2 & ~ATTR_MASK;
 			for (i = 0; i < Ln_ENTRIES; i++, pa += PAGE_SIZE) {
 				if (is_dumpable(pa))
@@ -327,25 +327,31 @@ minidumpsys(struct dumperinfo *di)
 			error = blk_flush(di);
 			if (error)
 				goto fail;
-		} else if (l2 == NULL) {
+		} else if ((*l1 & ATTR_DESCR_MASK) == L1_BLOCK) {
+			/*
+			 * Handle a 1GB block mapping: write out 512 fake L2
+			 * pages.
+			 */
 			pa = (*l1 & ~ATTR_MASK) | (va & L1_OFFSET);
 
-			/* Generate fake l3 entries based upon the l1 entry */
 			for (i = 0; i < Ln_ENTRIES; i++) {
-				tmpbuffer[i] = pa + (i * PAGE_SIZE) |
-				    ATTR_DEFAULT | L3_PAGE;
+				for (j = 0; j < Ln_ENTRIES; j++) {
+					tmpbuffer[j] = pa + i * L2_SIZE +
+					    j * PAGE_SIZE | ATTR_DEFAULT |
+					    L3_PAGE;
+				}
+				error = blk_write(di, (char *)&tmpbuffer, 0,
+				    PAGE_SIZE);
+				if (error)
+					goto fail;
 			}
-			/* We always write a page, even if it is zero */
-			error = blk_write(di, (char *)&tmpbuffer, 0, PAGE_SIZE);
-			if (error)
-				goto fail;
 			/* flush, in case we reuse tmpbuffer in the same block*/
 			error = blk_flush(di);
 			if (error)
 				goto fail;
 			bzero(&tmpbuffer, sizeof(tmpbuffer));
+			va += L1_SIZE - L2_SIZE;
 		} else if ((*l2 & ATTR_DESCR_MASK) == L2_BLOCK) {
-			/* TODO: Handle an invalid L2 entry */
 			pa = (*l2 & ~ATTR_MASK) | (va & L2_OFFSET);
 
 			/* Generate fake l3 entries based upon the l1 entry */
@@ -353,7 +359,6 @@ minidumpsys(struct dumperinfo *di)
 				tmpbuffer[i] = pa + (i * PAGE_SIZE) |
 				    ATTR_DEFAULT | L3_PAGE;
 			}
-			/* We always write a page, even if it is zero */
 			error = blk_write(di, (char *)&tmpbuffer, 0, PAGE_SIZE);
 			if (error)
 				goto fail;
@@ -366,7 +371,6 @@ minidumpsys(struct dumperinfo *di)
 		} else {
 			pa = *l2 & ~ATTR_MASK;
 
-			/* We always write a page, even if it is zero */
 			error = blk_write(di, NULL, pa, PAGE_SIZE);
 			if (error)
 				goto fail;