Revision 05b4ebd2c7cbb3671c376754b37b4963dd08a3a2 authored by Linus Torvalds on 23 October 2022, 22:00:43 UTC, committed by Linus Torvalds on 23 October 2022, 22:00:43 UTC
Pull kvm fixes from Paolo Bonzini: "RISC-V: - Fix compilation without RISCV_ISA_ZICBOM - Fix kvm_riscv_vcpu_timer_pending() for Sstc ARM: - Fix a bug preventing restoring an ITS containing mappings for very large and very sparse device topology - Work around a relocation handling error when compiling the nVHE object with profile optimisation - Fix for stage-2 invalidation holding the VM MMU lock for too long by limiting the walk to the largest block mapping size - Enable stack protection and branch profiling for VHE - Two selftest fixes x86: - add compat implementation for KVM_X86_SET_MSR_FILTER ioctl selftests: - synchronize includes between include/uapi and tools/include/uapi" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: tools: include: sync include/api/linux/kvm.h KVM: x86: Add compat handler for KVM_X86_SET_MSR_FILTER KVM: x86: Copy filter arg outside kvm_vm_ioctl_set_msr_filter() kvm: Add support for arch compat vm ioctls RISC-V: KVM: Fix kvm_riscv_vcpu_timer_pending() for Sstc RISC-V: Fix compilation without RISCV_ISA_ZICBOM KVM: arm64: vgic: Fix exit condition in scan_its_table() KVM: arm64: nvhe: Fix build with profile optimization KVM: selftests: Fix number of pages for memory slot in memslot_modification_stress_test KVM: arm64: selftests: Fix multiple versions of GIC creation KVM: arm64: Enable stack protection and branch profiling for VHE KVM: arm64: Limit stage2_apply_range() batch size to largest block KVM: arm64: Work out supported block level at compile time
page_poison.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/mmdebug.h>
#include <linux/highmem.h>
#include <linux/page_ext.h>
#include <linux/poison.h>
#include <linux/ratelimit.h>
#include <linux/kasan.h>
bool _page_poisoning_enabled_early;
EXPORT_SYMBOL(_page_poisoning_enabled_early);
DEFINE_STATIC_KEY_FALSE(_page_poisoning_enabled);
EXPORT_SYMBOL(_page_poisoning_enabled);
static int __init early_page_poison_param(char *buf)
{
return kstrtobool(buf, &_page_poisoning_enabled_early);
}
early_param("page_poison", early_page_poison_param);
static void poison_page(struct page *page)
{
void *addr = kmap_atomic(page);
/* KASAN still think the page is in-use, so skip it. */
kasan_disable_current();
memset(kasan_reset_tag(addr), PAGE_POISON, PAGE_SIZE);
kasan_enable_current();
kunmap_atomic(addr);
}
void __kernel_poison_pages(struct page *page, int n)
{
int i;
for (i = 0; i < n; i++)
poison_page(page + i);
}
static bool single_bit_flip(unsigned char a, unsigned char b)
{
unsigned char error = a ^ b;
return error && !(error & (error - 1));
}
static void check_poison_mem(struct page *page, unsigned char *mem, size_t bytes)
{
static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 10);
unsigned char *start;
unsigned char *end;
start = memchr_inv(mem, PAGE_POISON, bytes);
if (!start)
return;
for (end = mem + bytes - 1; end > start; end--) {
if (*end != PAGE_POISON)
break;
}
if (!__ratelimit(&ratelimit))
return;
else if (start == end && single_bit_flip(*start, PAGE_POISON))
pr_err("pagealloc: single bit error\n");
else
pr_err("pagealloc: memory corruption\n");
print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1, start,
end - start + 1, 1);
dump_stack();
dump_page(page, "pagealloc: corrupted page details");
}
static void unpoison_page(struct page *page)
{
void *addr;
addr = kmap_atomic(page);
kasan_disable_current();
/*
* Page poisoning when enabled poisons each and every page
* that is freed to buddy. Thus no extra check is done to
* see if a page was poisoned.
*/
check_poison_mem(page, kasan_reset_tag(addr), PAGE_SIZE);
kasan_enable_current();
kunmap_atomic(addr);
}
void __kernel_unpoison_pages(struct page *page, int n)
{
int i;
for (i = 0; i < n; i++)
unpoison_page(page + i);
}
#ifndef CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
/* This function does nothing, all work is done via poison pages */
}
#endif
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