blob: df994d1649f80f4d73831debdf0dd0fe4c35a640 [file] [log] [blame]
// Copyright 2020 The Fuchsia Authors
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT
#include "vm/pmm_checker.h"
#include <assert.h>
#include <lib/cmdline.h>
#include <platform.h>
#include <sys/types.h>
#include <vm/physmap.h>
namespace {
// The value 0x43 was chosen because it stands out when interpreted as ASCII ('C') and is an odd
// value that is less likely to occur natually (e.g. arm64 instructions are 4-byte aligned).
constexpr uint8_t kPatternOneByte = 0x43u;
constexpr uint64_t kPattern = 0x4343434343434343ull;
} // namespace
void PmmChecker::Arm() { armed_ = true; }
void PmmChecker::Disarm() { armed_ = false; }
void PmmChecker::FillPattern(vm_page_t* page) {
DEBUG_ASSERT(page->is_free());
void* kvaddr = paddr_to_physmap(page->paddr());
DEBUG_ASSERT(is_kernel_address(reinterpret_cast<vaddr_t>(kvaddr)));
memset(kvaddr, kPatternOneByte, PAGE_SIZE);
}
bool PmmChecker::ValidatePattern(vm_page_t* page) {
if (!armed_) {
return true;
}
// Validate the pattern. There's a decent chance that, on arm64, checking 8 bytes at a time will
// be faster than 1 byte at time.
auto kvaddr = static_cast<uint64_t*>(paddr_to_physmap(page->paddr()));
for (size_t j = 0; j < PAGE_SIZE / 8; ++j) {
if (kvaddr[j] != kPattern) {
return false;
}
}
return true;
}
static void DumpPageAndPanic(vm_page_t* page) {
platform_panic_start();
auto kvaddr = static_cast<void*>(paddr_to_physmap(page->paddr()));
printf("pmm checker found unexpected pattern in page at %p\n", kvaddr);
printf("dump of page follows\n");
hexdump8(kvaddr, PAGE_SIZE);
panic("pmm corruption suspected\n" );
}
void PmmChecker::AssertPattern(vm_page_t* page) {
if (!ValidatePattern(page)) {
DumpPageAndPanic(page);
}
}