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Fix handling of 1GB mappings in the arm64 minidump code.

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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.
This commit is contained in:
markj 2020-04-24 18:47:57 +00:00
parent 143b039d73
commit 890e35e73a
1 changed files with 28 additions and 24 deletions
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52
sys/arm64/arm64/minidump_machdep.c
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@ -34,8 +34,6 @@ __FBSDID("$FreeBSD$");
#include "opt_watchdog.h" #include "opt_watchdog.h"
#include "opt_watchdog.h"
#include <sys/param.h> #include <sys/param.h>
#include <sys/systm.h> #include <sys/systm.h>
#include <sys/conf.h> #include <sys/conf.h>
@ -68,7 +66,7 @@ static size_t fragsz;
static void *dump_va; static void *dump_va;
static size_t counter, progress, dumpsize; 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); CTASSERT(sizeof(*vm_page_dump) == 8);
@ -210,16 +208,14 @@ blk_write(struct dumperinfo *di, char *ptr, vm_paddr_t pa, size_t sz)
int int
minidumpsys(struct dumperinfo *di) minidumpsys(struct dumperinfo *di)
{ {
struct minidumphdr mdhdr;
pd_entry_t *l0, *l1, *l2; pd_entry_t *l0, *l1, *l2;
pt_entry_t *l3; pt_entry_t *l3;
uint32_t pmapsize;
vm_offset_t va; vm_offset_t va;
vm_paddr_t pa; vm_paddr_t pa;
int error;
uint64_t bits; uint64_t bits;
int i, bit; uint32_t pmapsize;
int retry_count; int bit, error, i, j, retry_count;
struct minidumphdr mdhdr;
retry_count = 0; retry_count = 0;
retry: retry:
@ -231,11 +227,15 @@ minidumpsys(struct dumperinfo *di)
if (!pmap_get_tables(pmap_kernel(), va, &l0, &l1, &l2, &l3)) if (!pmap_get_tables(pmap_kernel(), va, &l0, &l1, &l2, &l3))
continue; continue;
/* We should always be using the l2 table for kvm */ if ((*l1 & ATTR_DESCR_MASK) == L1_BLOCK) {
if (l2 == NULL) pa = *l1 & ~ATTR_MASK;
continue; for (i = 0; i < Ln_ENTRIES * Ln_ENTRIES;
i++, pa += PAGE_SIZE)
if ((*l2 & ATTR_DESCR_MASK) == L2_BLOCK) { 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; pa = *l2 & ~ATTR_MASK;
for (i = 0; i < Ln_ENTRIES; i++, pa += PAGE_SIZE) { for (i = 0; i < Ln_ENTRIES; i++, pa += PAGE_SIZE) {
if (is_dumpable(pa)) if (is_dumpable(pa))
@ -327,25 +327,31 @@ minidumpsys(struct dumperinfo *di)
error = blk_flush(di); error = blk_flush(di);
if (error) if (error)
goto fail; 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); pa = (*l1 & ~ATTR_MASK) | (va & L1_OFFSET);
/* Generate fake l3 entries based upon the l1 entry */
for (i = 0; i < Ln_ENTRIES; i++) { for (i = 0; i < Ln_ENTRIES; i++) {
tmpbuffer[i] = pa + (i * PAGE_SIZE) | for (j = 0; j < Ln_ENTRIES; j++) {
ATTR_DEFAULT | L3_PAGE; 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*/ /* flush, in case we reuse tmpbuffer in the same block*/
error = blk_flush(di); error = blk_flush(di);
if (error) if (error)
goto fail; goto fail;
bzero(&tmpbuffer, sizeof(tmpbuffer)); bzero(&tmpbuffer, sizeof(tmpbuffer));
va += L1_SIZE - L2_SIZE;
} else if ((*l2 & ATTR_DESCR_MASK) == L2_BLOCK) { } else if ((*l2 & ATTR_DESCR_MASK) == L2_BLOCK) {
/* TODO: Handle an invalid L2 entry */
pa = (*l2 & ~ATTR_MASK) | (va & L2_OFFSET); pa = (*l2 & ~ATTR_MASK) | (va & L2_OFFSET);
/* Generate fake l3 entries based upon the l1 entry */ /* Generate fake l3 entries based upon the l1 entry */
@ -353,7 +359,6 @@ minidumpsys(struct dumperinfo *di)
tmpbuffer[i] = pa + (i * PAGE_SIZE) | tmpbuffer[i] = pa + (i * PAGE_SIZE) |
ATTR_DEFAULT | L3_PAGE; ATTR_DEFAULT | L3_PAGE;
} }
/* We always write a page, even if it is zero */
error = blk_write(di, (char *)&tmpbuffer, 0, PAGE_SIZE); error = blk_write(di, (char *)&tmpbuffer, 0, PAGE_SIZE);
if (error) if (error)
goto fail; goto fail;
@ -366,7 +371,6 @@ minidumpsys(struct dumperinfo *di)
} else { } else {
pa = *l2 & ~ATTR_MASK; pa = *l2 & ~ATTR_MASK;
/* We always write a page, even if it is zero */
error = blk_write(di, NULL, pa, PAGE_SIZE); error = blk_write(di, NULL, pa, PAGE_SIZE);
if (error) if (error)
goto fail; goto fail;