diff options
author | Levin, Alexander (Sasha Levin) <alexander.levin@verizon.com> | 2017-11-16 04:36:02 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-16 05:21:05 +0300 |
commit | 4675ff05de2d76d167336b368bd07f3fef6ed5a6 (patch) | |
tree | 212d8adf40e13c2a27ac7834d14ca4900923b98c /arch/x86/mm | |
parent | d8be75663cec0069b85f80191abd2682ce4a512f (diff) | |
download | linux-4675ff05de2d76d167336b368bd07f3fef6ed5a6.tar.xz |
kmemcheck: rip it out
Fix up makefiles, remove references, and git rm kmemcheck.
Link: http://lkml.kernel.org/r/20171007030159.22241-4-alexander.levin@verizon.com
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Tim Hansen <devtimhansen@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/mm')
-rw-r--r-- | arch/x86/mm/Makefile | 2 | ||||
-rw-r--r-- | arch/x86/mm/init.c | 5 | ||||
-rw-r--r-- | arch/x86/mm/kmemcheck/Makefile | 1 | ||||
-rw-r--r-- | arch/x86/mm/kmemcheck/error.c | 227 | ||||
-rw-r--r-- | arch/x86/mm/kmemcheck/error.h | 15 | ||||
-rw-r--r-- | arch/x86/mm/kmemcheck/kmemcheck.c | 658 | ||||
-rw-r--r-- | arch/x86/mm/kmemcheck/opcode.c | 106 | ||||
-rw-r--r-- | arch/x86/mm/kmemcheck/opcode.h | 9 | ||||
-rw-r--r-- | arch/x86/mm/kmemcheck/pte.c | 22 | ||||
-rw-r--r-- | arch/x86/mm/kmemcheck/pte.h | 10 | ||||
-rw-r--r-- | arch/x86/mm/kmemcheck/selftest.c | 70 | ||||
-rw-r--r-- | arch/x86/mm/kmemcheck/selftest.h | 6 | ||||
-rw-r--r-- | arch/x86/mm/kmemcheck/shadow.c | 173 | ||||
-rw-r--r-- | arch/x86/mm/kmemcheck/shadow.h | 18 |
14 files changed, 2 insertions, 1320 deletions
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index 7ba7f3d7f477..8e13b8cc6bed 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -29,8 +29,6 @@ obj-$(CONFIG_X86_PTDUMP) += debug_pagetables.o obj-$(CONFIG_HIGHMEM) += highmem_32.o -obj-$(CONFIG_KMEMCHECK) += kmemcheck/ - KASAN_SANITIZE_kasan_init_$(BITS).o := n obj-$(CONFIG_KASAN) += kasan_init_$(BITS).o diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index ef94620ceb8a..6fdf91ef130a 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -163,12 +163,11 @@ static int page_size_mask; static void __init probe_page_size_mask(void) { /* - * For CONFIG_KMEMCHECK or pagealloc debugging, identity mapping will - * use small pages. + * For pagealloc debugging, identity mapping will use small pages. * This will simplify cpa(), which otherwise needs to support splitting * large pages into small in interrupt context, etc. */ - if (boot_cpu_has(X86_FEATURE_PSE) && !debug_pagealloc_enabled() && !IS_ENABLED(CONFIG_KMEMCHECK)) + if (boot_cpu_has(X86_FEATURE_PSE) && !debug_pagealloc_enabled()) page_size_mask |= 1 << PG_LEVEL_2M; else direct_gbpages = 0; diff --git a/arch/x86/mm/kmemcheck/Makefile b/arch/x86/mm/kmemcheck/Makefile deleted file mode 100644 index 520b3bce4095..000000000000 --- a/arch/x86/mm/kmemcheck/Makefile +++ /dev/null @@ -1 +0,0 @@ -obj-y := error.o kmemcheck.o opcode.o pte.o selftest.o shadow.o diff --git a/arch/x86/mm/kmemcheck/error.c b/arch/x86/mm/kmemcheck/error.c index 872ec4159a68..cec594032515 100644 --- a/arch/x86/mm/kmemcheck/error.c +++ b/arch/x86/mm/kmemcheck/error.c @@ -1,228 +1 @@ // SPDX-License-Identifier: GPL-2.0 -#include <linux/interrupt.h> -#include <linux/kdebug.h> -#include <linux/kmemcheck.h> -#include <linux/kernel.h> -#include <linux/types.h> -#include <linux/ptrace.h> -#include <linux/stacktrace.h> -#include <linux/string.h> - -#include "error.h" -#include "shadow.h" - -enum kmemcheck_error_type { - KMEMCHECK_ERROR_INVALID_ACCESS, - KMEMCHECK_ERROR_BUG, -}; - -#define SHADOW_COPY_SIZE (1 << CONFIG_KMEMCHECK_SHADOW_COPY_SHIFT) - -struct kmemcheck_error { - enum kmemcheck_error_type type; - - union { - /* KMEMCHECK_ERROR_INVALID_ACCESS */ - struct { - /* Kind of access that caused the error */ - enum kmemcheck_shadow state; - /* Address and size of the erroneous read */ - unsigned long address; - unsigned int size; - }; - }; - - struct pt_regs regs; - struct stack_trace trace; - unsigned long trace_entries[32]; - - /* We compress it to a char. */ - unsigned char shadow_copy[SHADOW_COPY_SIZE]; - unsigned char memory_copy[SHADOW_COPY_SIZE]; -}; - -/* - * Create a ring queue of errors to output. We can't call printk() directly - * from the kmemcheck traps, since this may call the console drivers and - * result in a recursive fault. - */ -static struct kmemcheck_error error_fifo[CONFIG_KMEMCHECK_QUEUE_SIZE]; -static unsigned int error_count; -static unsigned int error_rd; -static unsigned int error_wr; -static unsigned int error_missed_count; - -static struct kmemcheck_error *error_next_wr(void) -{ - struct kmemcheck_error *e; - - if (error_count == ARRAY_SIZE(error_fifo)) { - ++error_missed_count; - return NULL; - } - - e = &error_fifo[error_wr]; - if (++error_wr == ARRAY_SIZE(error_fifo)) - error_wr = 0; - ++error_count; - return e; -} - -static struct kmemcheck_error *error_next_rd(void) -{ - struct kmemcheck_error *e; - - if (error_count == 0) - return NULL; - - e = &error_fifo[error_rd]; - if (++error_rd == ARRAY_SIZE(error_fifo)) - error_rd = 0; - --error_count; - return e; -} - -void kmemcheck_error_recall(void) -{ - static const char *desc[] = { - [KMEMCHECK_SHADOW_UNALLOCATED] = "unallocated", - [KMEMCHECK_SHADOW_UNINITIALIZED] = "uninitialized", - [KMEMCHECK_SHADOW_INITIALIZED] = "initialized", - [KMEMCHECK_SHADOW_FREED] = "freed", - }; - - static const char short_desc[] = { - [KMEMCHECK_SHADOW_UNALLOCATED] = 'a', - [KMEMCHECK_SHADOW_UNINITIALIZED] = 'u', - [KMEMCHECK_SHADOW_INITIALIZED] = 'i', - [KMEMCHECK_SHADOW_FREED] = 'f', - }; - - struct kmemcheck_error *e; - unsigned int i; - - e = error_next_rd(); - if (!e) - return; - - switch (e->type) { - case KMEMCHECK_ERROR_INVALID_ACCESS: - printk(KERN_WARNING "WARNING: kmemcheck: Caught %d-bit read from %s memory (%p)\n", - 8 * e->size, e->state < ARRAY_SIZE(desc) ? - desc[e->state] : "(invalid shadow state)", - (void *) e->address); - - printk(KERN_WARNING); - for (i = 0; i < SHADOW_COPY_SIZE; ++i) - printk(KERN_CONT "%02x", e->memory_copy[i]); - printk(KERN_CONT "\n"); - - printk(KERN_WARNING); - for (i = 0; i < SHADOW_COPY_SIZE; ++i) { - if (e->shadow_copy[i] < ARRAY_SIZE(short_desc)) - printk(KERN_CONT " %c", short_desc[e->shadow_copy[i]]); - else - printk(KERN_CONT " ?"); - } - printk(KERN_CONT "\n"); - printk(KERN_WARNING "%*c\n", 2 + 2 - * (int) (e->address & (SHADOW_COPY_SIZE - 1)), '^'); - break; - case KMEMCHECK_ERROR_BUG: - printk(KERN_EMERG "ERROR: kmemcheck: Fatal error\n"); - break; - } - - __show_regs(&e->regs, 1); - print_stack_trace(&e->trace, 0); -} - -static void do_wakeup(unsigned long data) -{ - while (error_count > 0) - kmemcheck_error_recall(); - - if (error_missed_count > 0) { - printk(KERN_WARNING "kmemcheck: Lost %d error reports because " - "the queue was too small\n", error_missed_count); - error_missed_count = 0; - } -} - -static DECLARE_TASKLET(kmemcheck_tasklet, &do_wakeup, 0); - -/* - * Save the context of an error report. - */ -void kmemcheck_error_save(enum kmemcheck_shadow state, - unsigned long address, unsigned int size, struct pt_regs *regs) -{ - static unsigned long prev_ip; - - struct kmemcheck_error *e; - void *shadow_copy; - void *memory_copy; - - /* Don't report several adjacent errors from the same EIP. */ - if (regs->ip == prev_ip) - return; - prev_ip = regs->ip; - - e = error_next_wr(); - if (!e) - return; - - e->type = KMEMCHECK_ERROR_INVALID_ACCESS; - - e->state = state; - e->address = address; - e->size = size; - - /* Save regs */ - memcpy(&e->regs, regs, sizeof(*regs)); - - /* Save stack trace */ - e->trace.nr_entries = 0; - e->trace.entries = e->trace_entries; - e->trace.max_entries = ARRAY_SIZE(e->trace_entries); - e->trace.skip = 0; - save_stack_trace_regs(regs, &e->trace); - - /* Round address down to nearest 16 bytes */ - shadow_copy = kmemcheck_shadow_lookup(address - & ~(SHADOW_COPY_SIZE - 1)); - BUG_ON(!shadow_copy); - - memcpy(e->shadow_copy, shadow_copy, SHADOW_COPY_SIZE); - - kmemcheck_show_addr(address); - memory_copy = (void *) (address & ~(SHADOW_COPY_SIZE - 1)); - memcpy(e->memory_copy, memory_copy, SHADOW_COPY_SIZE); - kmemcheck_hide_addr(address); - - tasklet_hi_schedule_first(&kmemcheck_tasklet); -} - -/* - * Save the context of a kmemcheck bug. - */ -void kmemcheck_error_save_bug(struct pt_regs *regs) -{ - struct kmemcheck_error *e; - - e = error_next_wr(); - if (!e) - return; - - e->type = KMEMCHECK_ERROR_BUG; - - memcpy(&e->regs, regs, sizeof(*regs)); - - e->trace.nr_entries = 0; - e->trace.entries = e->trace_entries; - e->trace.max_entries = ARRAY_SIZE(e->trace_entries); - e->trace.skip = 1; - save_stack_trace(&e->trace); - - tasklet_hi_schedule_first(&kmemcheck_tasklet); -} diff --git a/arch/x86/mm/kmemcheck/error.h b/arch/x86/mm/kmemcheck/error.h index 39f80d7a874d..ea32a7d3cf1b 100644 --- a/arch/x86/mm/kmemcheck/error.h +++ b/arch/x86/mm/kmemcheck/error.h @@ -1,16 +1 @@ /* SPDX-License-Identifier: GPL-2.0 */ -#ifndef ARCH__X86__MM__KMEMCHECK__ERROR_H -#define ARCH__X86__MM__KMEMCHECK__ERROR_H - -#include <linux/ptrace.h> - -#include "shadow.h" - -void kmemcheck_error_save(enum kmemcheck_shadow state, - unsigned long address, unsigned int size, struct pt_regs *regs); - -void kmemcheck_error_save_bug(struct pt_regs *regs); - -void kmemcheck_error_recall(void); - -#endif diff --git a/arch/x86/mm/kmemcheck/kmemcheck.c b/arch/x86/mm/kmemcheck/kmemcheck.c deleted file mode 100644 index 4515bae36bbe..000000000000 --- a/arch/x86/mm/kmemcheck/kmemcheck.c +++ /dev/null @@ -1,658 +0,0 @@ -/** - * kmemcheck - a heavyweight memory checker for the linux kernel - * Copyright (C) 2007, 2008 Vegard Nossum <vegardno@ifi.uio.no> - * (With a lot of help from Ingo Molnar and Pekka Enberg.) - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License (version 2) as - * published by the Free Software Foundation. - */ - -#include <linux/init.h> -#include <linux/interrupt.h> -#include <linux/kallsyms.h> -#include <linux/kernel.h> -#include <linux/kmemcheck.h> -#include <linux/mm.h> -#include <linux/page-flags.h> -#include <linux/percpu.h> -#include <linux/ptrace.h> -#include <linux/string.h> -#include <linux/types.h> - -#include <asm/cacheflush.h> -#include <asm/kmemcheck.h> -#include <asm/pgtable.h> -#include <asm/tlbflush.h> - -#include "error.h" -#include "opcode.h" -#include "pte.h" -#include "selftest.h" -#include "shadow.h" - - -#ifdef CONFIG_KMEMCHECK_DISABLED_BY_DEFAULT -# define KMEMCHECK_ENABLED 0 -#endif - -#ifdef CONFIG_KMEMCHECK_ENABLED_BY_DEFAULT -# define KMEMCHECK_ENABLED 1 -#endif - -#ifdef CONFIG_KMEMCHECK_ONESHOT_BY_DEFAULT -# define KMEMCHECK_ENABLED 2 -#endif - -int kmemcheck_enabled = KMEMCHECK_ENABLED; - -int __init kmemcheck_init(void) -{ -#ifdef CONFIG_SMP - /* - * Limit SMP to use a single CPU. We rely on the fact that this code - * runs before SMP is set up. - */ - if (setup_max_cpus > 1) { - printk(KERN_INFO - "kmemcheck: Limiting number of CPUs to 1.\n"); - setup_max_cpus = 1; - } -#endif - - if (!kmemcheck_selftest()) { - printk(KERN_INFO "kmemcheck: self-tests failed; disabling\n"); - kmemcheck_enabled = 0; - return -EINVAL; - } - - printk(KERN_INFO "kmemcheck: Initialized\n"); - return 0; -} - -early_initcall(kmemcheck_init); - -/* - * We need to parse the kmemcheck= option before any memory is allocated. - */ -static int __init param_kmemcheck(char *str) -{ - int val; - int ret; - - if (!str) - return -EINVAL; - - ret = kstrtoint(str, 0, &val); - if (ret) - return ret; - kmemcheck_enabled = val; - return 0; -} - -early_param("kmemcheck", param_kmemcheck); - -int kmemcheck_show_addr(unsigned long address) -{ - pte_t *pte; - - pte = kmemcheck_pte_lookup(address); - if (!pte) - return 0; - - set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT)); - __flush_tlb_one(address); - return 1; -} - -int kmemcheck_hide_addr(unsigned long address) -{ - pte_t *pte; - - pte = kmemcheck_pte_lookup(address); - if (!pte) - return 0; - - set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT)); - __flush_tlb_one(address); - return 1; -} - -struct kmemcheck_context { - bool busy; - int balance; - - /* - * There can be at most two memory operands to an instruction, but - * each address can cross a page boundary -- so we may need up to - * four addresses that must be hidden/revealed for each fault. - */ - unsigned long addr[4]; - unsigned long n_addrs; - unsigned long flags; - - /* Data size of the instruction that caused a fault. */ - unsigned int size; -}; - -static DEFINE_PER_CPU(struct kmemcheck_context, kmemcheck_context); - -bool kmemcheck_active(struct pt_regs *regs) -{ - struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context); - - return data->balance > 0; -} - -/* Save an address that needs to be shown/hidden */ -static void kmemcheck_save_addr(unsigned long addr) -{ - struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context); - - BUG_ON(data->n_addrs >= ARRAY_SIZE(data->addr)); - data->addr[data->n_addrs++] = addr; -} - -static unsigned int kmemcheck_show_all(void) -{ - struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context); - unsigned int i; - unsigned int n; - - n = 0; - for (i = 0; i < data->n_addrs; ++i) - n += kmemcheck_show_addr(data->addr[i]); - - return n; -} - -static unsigned int kmemcheck_hide_all(void) -{ - struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context); - unsigned int i; - unsigned int n; - - n = 0; - for (i = 0; i < data->n_addrs; ++i) - n += kmemcheck_hide_addr(data->addr[i]); - - return n; -} - -/* - * Called from the #PF handler. - */ -void kmemcheck_show(struct pt_regs *regs) -{ - struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context); - - BUG_ON(!irqs_disabled()); - - if (unlikely(data->balance != 0)) { - kmemcheck_show_all(); - kmemcheck_error_save_bug(regs); - data->balance = 0; - return; - } - - /* - * None of the addresses actually belonged to kmemcheck. Note that - * this is not an error. - */ - if (kmemcheck_show_all() == 0) - return; - - ++data->balance; - - /* - * The IF needs to be cleared as well, so that the faulting - * instruction can run "uninterrupted". Otherwise, we might take - * an interrupt and start executing that before we've had a chance - * to hide the page again. - * - * NOTE: In the rare case of multiple faults, we must not override - * the original flags: - */ - if (!(regs->flags & X86_EFLAGS_TF)) - data->flags = regs->flags; - - regs->flags |= X86_EFLAGS_TF; - regs->flags &= ~X86_EFLAGS_IF; -} - -/* - * Called from the #DB handler. - */ -void kmemcheck_hide(struct pt_regs *regs) -{ - struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context); - int n; - - BUG_ON(!irqs_disabled()); - - if (unlikely(data->balance != 1)) { - kmemcheck_show_all(); - kmemcheck_error_save_bug(regs); - data->n_addrs = 0; - data->balance = 0; - - if (!(data->flags & X86_EFLAGS_TF)) - regs->flags &= ~X86_EFLAGS_TF; - if (data->flags & X86_EFLAGS_IF) - regs->flags |= X86_EFLAGS_IF; - return; - } - - if (kmemcheck_enabled) - n = kmemcheck_hide_all(); - else - n = kmemcheck_show_all(); - - if (n == 0) - return; - - --data->balance; - - data->n_addrs = 0; - - if (!(data->flags & X86_EFLAGS_TF)) - regs->flags &= ~X86_EFLAGS_TF; - if (data->flags & X86_EFLAGS_IF) - regs->flags |= X86_EFLAGS_IF; -} - -void kmemcheck_show_pages(struct page *p, unsigned int n) -{ - unsigned int i; - - for (i = 0; i < n; ++i) { - unsigned long address; - pte_t *pte; - unsigned int level; - - address = (unsigned long) page_address(&p[i]); - pte = lookup_address(address, &level); - BUG_ON(!pte); - BUG_ON(level != PG_LEVEL_4K); - - set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT)); - set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_HIDDEN)); - __flush_tlb_one(address); - } -} - -bool kmemcheck_page_is_tracked(struct page *p) -{ - /* This will also check the "hidden" flag of the PTE. */ - return kmemcheck_pte_lookup((unsigned long) page_address(p)); -} - -void kmemcheck_hide_pages(struct page *p, unsigned int n) -{ - unsigned int i; - - for (i = 0; i < n; ++i) { - unsigned long address; - pte_t *pte; - unsigned int level; - - address = (unsigned long) page_address(&p[i]); - pte = lookup_address(address, &level); - BUG_ON(!pte); - BUG_ON(level != PG_LEVEL_4K); - - set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT)); - set_pte(pte, __pte(pte_val(*pte) | _PAGE_HIDDEN)); - __flush_tlb_one(address); - } -} - -/* Access may NOT cross page boundary */ -static void kmemcheck_read_strict(struct pt_regs *regs, - unsigned long addr, unsigned int size) -{ - void *shadow; - enum kmemcheck_shadow status; - - shadow = kmemcheck_shadow_lookup(addr); - if (!shadow) - return; - - kmemcheck_save_addr(addr); - status = kmemcheck_shadow_test(shadow, size); - if (status == KMEMCHECK_SHADOW_INITIALIZED) - return; - - if (kmemcheck_enabled) - kmemcheck_error_save(status, addr, size, regs); - - if (kmemcheck_enabled == 2) - kmemcheck_enabled = 0; - - /* Don't warn about it again. */ - kmemcheck_shadow_set(shadow, size); -} - -bool kmemcheck_is_obj_initialized(unsigned long addr, size_t size) -{ - enum kmemcheck_shadow status; - void *shadow; - - shadow = kmemcheck_shadow_lookup(addr); - if (!shadow) - return true; - - status = kmemcheck_shadow_test_all(shadow, size); - - return status == KMEMCHECK_SHADOW_INITIALIZED; -} - -/* Access may cross page boundary */ -static void kmemcheck_read(struct pt_regs *regs, - unsigned long addr, unsigned int size) -{ - unsigned long page = addr & PAGE_MASK; - unsigned long next_addr = addr + size - 1; - unsigned long next_page = next_addr & PAGE_MASK; - - if (likely(page == next_page)) { - kmemcheck_read_strict(regs, addr, size); - return; - } - - /* - * What we do is basically to split the access across the - * two pages and handle each part separately. Yes, this means - * that we may now see reads that are 3 + 5 bytes, for - * example (and if both are uninitialized, there will be two - * reports), but it makes the code a lot simpler. - */ - kmemcheck_read_strict(regs, addr, next_page - addr); - kmemcheck_read_strict(regs, next_page, next_addr - next_page); -} - -static void kmemcheck_write_strict(struct pt_regs *regs, - unsigned long addr, unsigned int size) -{ - void *shadow; - - shadow = kmemcheck_shadow_lookup(addr); - if (!shadow) - return; - - kmemcheck_save_addr(addr); - kmemcheck_shadow_set(shadow, size); -} - -static void kmemcheck_write(struct pt_regs *regs, - unsigned long addr, unsigned int size) -{ - unsigned long page = addr & PAGE_MASK; - unsigned long next_addr = addr + size - 1; - unsigned long next_page = next_addr & PAGE_MASK; - - if (likely(page == next_page)) { - kmemcheck_write_strict(regs, addr, size); - return; - } - - /* See comment in kmemcheck_read(). */ - kmemcheck_write_strict(regs, addr, next_page - addr); - kmemcheck_write_strict(regs, next_page, next_addr - next_page); -} - -/* - * Copying is hard. We have two addresses, each of which may be split across - * a page (and each page will have different shadow addresses). - */ -static void kmemcheck_copy(struct pt_regs *regs, - unsigned long src_addr, unsigned long dst_addr, unsigned int size) -{ - uint8_t shadow[8]; - enum kmemcheck_shadow status; - - unsigned long page; - unsigned long next_addr; - unsigned long next_page; - - uint8_t *x; - unsigned int i; - unsigned int n; - - BUG_ON(size > sizeof(shadow)); - - page = src_addr & PAGE_MASK; - next_addr = src_addr + size - 1; - next_page = next_addr & PAGE_MASK; - - if (likely(page == next_page)) { - /* Same page */ - x = kmemcheck_shadow_lookup(src_addr); - if (x) { - kmemcheck_save_addr(src_addr); - for (i = 0; i < size; ++i) - shadow[i] = x[i]; - } else { - for (i = 0; i < size; ++i) - shadow[i] = KMEMCHECK_SHADOW_INITIALIZED; - } - } else { - n = next_page - src_addr; - BUG_ON(n > sizeof(shadow)); - - /* First page */ - x = kmemcheck_shadow_lookup(src_addr); - if (x) { - kmemcheck_save_addr(src_addr); - for (i = 0; i < n; ++i) - shadow[i] = x[i]; - } else { - /* Not tracked */ - for (i = 0; i < n; ++i) - shadow[i] = KMEMCHECK_SHADOW_INITIALIZED; - } - - /* Second page */ - x = kmemcheck_shadow_lookup(next_page); - if (x) { - kmemcheck_save_addr(next_page); - for (i = n; i < size; ++i) - shadow[i] = x[i - n]; - } else { - /* Not tracked */ - for (i = n; i < size; ++i) - shadow[i] = KMEMCHECK_SHADOW_INITIALIZED; - } - } - - page = dst_addr & PAGE_MASK; - next_addr = dst_addr + size - 1; - next_page = next_addr & PAGE_MASK; - - if (likely(page == next_page)) { - /* Same page */ - x = kmemcheck_shadow_lookup(dst_addr); - if (x) { - kmemcheck_save_addr(dst_addr); - for (i = 0; i < size; ++i) { - x[i] = shadow[i]; - shadow[i] = KMEMCHECK_SHADOW_INITIALIZED; - } - } - } else { - n = next_page - dst_addr; - BUG_ON(n > sizeof(shadow)); - - /* First page */ - x = kmemcheck_shadow_lookup(dst_addr); - if (x) { - kmemcheck_save_addr(dst_addr); - for (i = 0; i < n; ++i) { - x[i] = shadow[i]; - shadow[i] = KMEMCHECK_SHADOW_INITIALIZED; - } - } - - /* Second page */ - x = kmemcheck_shadow_lookup(next_page); - if (x) { - kmemcheck_save_addr(next_page); - for (i = n; i < size; ++i) { - x[i - n] = shadow[i]; - shadow[i] = KMEMCHECK_SHADOW_INITIALIZED; - } - } - } - - status = kmemcheck_shadow_test(shadow, size); - if (status == KMEMCHECK_SHADOW_INITIALIZED) - return; - - if (kmemcheck_enabled) - kmemcheck_error_save(status, src_addr, size, regs); - - if (kmemcheck_enabled == 2) - kmemcheck_enabled = 0; -} - -enum kmemcheck_method { - KMEMCHECK_READ, - KMEMCHECK_WRITE, -}; - -static void kmemcheck_access(struct pt_regs *regs, - unsigned long fallback_address, enum kmemcheck_method fallback_method) -{ - const uint8_t *insn; - const uint8_t *insn_primary; - unsigned int size; - - struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context); - - /* Recursive fault -- ouch. */ - if (data->busy) { - kmemcheck_show_addr(fallback_address); - kmemcheck_error_save_bug(regs); - return; - } - - data->busy = true; - - insn = (const uint8_t *) regs->ip; - insn_primary = kmemcheck_opcode_get_primary(insn); - - kmemcheck_opcode_decode(insn, &size); - - switch (insn_primary[0]) { -#ifdef CONFIG_KMEMCHECK_BITOPS_OK - /* AND, OR, XOR */ - /* - * Unfortunately, these instructions have to be excluded from - * our regular checking since they access only some (and not - * all) bits. This clears out "bogus" bitfield-access warnings. - */ - case 0x80: - case 0x81: - case 0x82: - case 0x83: - switch ((insn_primary[1] >> 3) & 7) { - /* OR */ - case 1: - /* AND */ - case 4: - /* XOR */ - case 6: - kmemcheck_write(regs, fallback_address, size); - goto out; - - /* ADD */ - case 0: - /* ADC */ - case 2: - /* SBB */ - case 3: - /* SUB */ - case 5: - /* CMP */ - case 7: - break; - } - break; -#endif - - /* MOVS, MOVSB, MOVSW, MOVSD */ - case 0xa4: - case 0xa5: - /* - * These instructions are special because they take two - * addresses, but we only get one page fault. - */ - kmemcheck_copy(regs, regs->si, regs->di, size); - goto out; - - /* CMPS, CMPSB, CMPSW, CMPSD */ - case 0xa6: - case 0xa7: - kmemcheck_read(regs, regs->si, size); - kmemcheck_read(regs, regs->di, size); - goto out; - } - - /* - * If the opcode isn't special in any way, we use the data from the - * page fault handler to determine the address and type of memory - * access. - */ - switch (fallback_method) { - case KMEMCHECK_READ: - kmemcheck_read(regs, fallback_address, size); - goto out; - case KMEMCHECK_WRITE: - kmemcheck_write(regs, fallback_address, size); - goto out; - } - -out: - data->busy = false; -} - -bool kmemcheck_fault(struct pt_regs *regs, unsigned long address, - unsigned long error_code) -{ - pte_t *pte; - - /* - * XXX: Is it safe to assume that memory accesses from virtual 86 - * mode or non-kernel code segments will _never_ access kernel - * memory (e.g. tracked pages)? For now, we need this to avoid - * invoking kmemcheck for PnP BIOS calls. - */ - if (regs->flags & X86_VM_MASK) - return false; - if (regs->cs != __KERNEL_CS) - return false; - - pte = kmemcheck_pte_lookup(address); - if (!pte) - return false; - - WARN_ON_ONCE(in_nmi()); - - if (error_code & 2) - kmemcheck_access(regs, address, KMEMCHECK_WRITE); - else - kmemcheck_access(regs, address, KMEMCHECK_READ); - - kmemcheck_show(regs); - return true; -} - -bool kmemcheck_trap(struct pt_regs *regs) -{ - if (!kmemcheck_active(regs)) - return false; - - /* We're done. */ - kmemcheck_hide(regs); - return true; -} diff --git a/arch/x86/mm/kmemcheck/opcode.c b/arch/x86/mm/kmemcheck/opcode.c index df8109ddf7fe..cec594032515 100644 --- a/arch/x86/mm/kmemcheck/opcode.c +++ b/arch/x86/mm/kmemcheck/opcode.c @@ -1,107 +1 @@ // SPDX-License-Identifier: GPL-2.0 -#include <linux/types.h> - -#include "opcode.h" - -static bool opcode_is_prefix(uint8_t b) -{ - return - /* Group 1 */ - b == 0xf0 || b == 0xf2 || b == 0xf3 - /* Group 2 */ - || b == 0x2e || b == 0x36 || b == 0x3e || b == 0x26 - || b == 0x64 || b == 0x65 - /* Group 3 */ - || b == 0x66 - /* Group 4 */ - || b == 0x67; -} - -#ifdef CONFIG_X86_64 -static bool opcode_is_rex_prefix(uint8_t b) -{ - return (b & 0xf0) == 0x40; -} -#else -static bool opcode_is_rex_prefix(uint8_t b) -{ - return false; -} -#endif - -#define REX_W (1 << 3) - -/* - * This is a VERY crude opcode decoder. We only need to find the size of the - * load/store that caused our #PF and this should work for all the opcodes - * that we care about. Moreover, the ones who invented this instruction set - * should be shot. - */ -void kmemcheck_opcode_decode(const uint8_t *op, unsigned int *size) -{ - /* Default operand size */ - int operand_size_override = 4; - - /* prefixes */ - for (; opcode_is_prefix(*op); ++op) { - if (*op == 0x66) - operand_size_override = 2; - } - - /* REX prefix */ - if (opcode_is_rex_prefix(*op)) { - uint8_t rex = *op; - - ++op; - if (rex & REX_W) { - switch (*op) { - case 0x63: - *size = 4; - return; - case 0x0f: - ++op; - - switch (*op) { - case 0xb6: - case 0xbe: - *size = 1; - return; - case 0xb7: - case 0xbf: - *size = 2; - return; - } - - break; - } - - *size = 8; - return; - } - } - - /* escape opcode */ - if (*op == 0x0f) { - ++op; - - /* - * This is move with zero-extend and sign-extend, respectively; - * we don't have to think about 0xb6/0xbe, because this is - * already handled in the conditional below. - */ - if (*op == 0xb7 || *op == 0xbf) - operand_size_override = 2; - } - - *size = (*op & 1) ? operand_size_override : 1; -} - -const uint8_t *kmemcheck_opcode_get_primary(const uint8_t *op) -{ - /* skip prefixes */ - while (opcode_is_prefix(*op)) - ++op; - if (opcode_is_rex_prefix(*op)) - ++op; - return op; -} diff --git a/arch/x86/mm/kmemcheck/opcode.h b/arch/x86/mm/kmemcheck/opcode.h index 51a1ce94c24a..ea32a7d3cf1b 100644 --- a/arch/x86/mm/kmemcheck/opcode.h +++ b/arch/x86/mm/kmemcheck/opcode.h @@ -1,10 +1 @@ /* SPDX-License-Identifier: GPL-2.0 */ -#ifndef ARCH__X86__MM__KMEMCHECK__OPCODE_H -#define ARCH__X86__MM__KMEMCHECK__OPCODE_H - -#include <linux/types.h> - -void kmemcheck_opcode_decode(const uint8_t *op, unsigned int *size); -const uint8_t *kmemcheck_opcode_get_primary(const uint8_t *op); - -#endif diff --git a/arch/x86/mm/kmemcheck/pte.c b/arch/x86/mm/kmemcheck/pte.c index 8a03be90272a..cec594032515 100644 --- a/arch/x86/mm/kmemcheck/pte.c +++ b/arch/x86/mm/kmemcheck/pte.c @@ -1,23 +1 @@ // SPDX-License-Identifier: GPL-2.0 -#include <linux/mm.h> - -#include <asm/pgtable.h> - -#include "pte.h" - -pte_t *kmemcheck_pte_lookup(unsigned long address) -{ - pte_t *pte; - unsigned int level; - - pte = lookup_address(address, &level); - if (!pte) - return NULL; - if (level != PG_LEVEL_4K) - return NULL; - if (!pte_hidden(*pte)) - return NULL; - - return pte; -} - diff --git a/arch/x86/mm/kmemcheck/pte.h b/arch/x86/mm/kmemcheck/pte.h index b595612382c2..ea32a7d3cf1b 100644 --- a/arch/x86/mm/kmemcheck/pte.h +++ b/arch/x86/mm/kmemcheck/pte.h @@ -1,11 +1 @@ /* SPDX-License-Identifier: GPL-2.0 */ -#ifndef ARCH__X86__MM__KMEMCHECK__PTE_H -#define ARCH__X86__MM__KMEMCHECK__PTE_H - -#include <linux/mm.h> - -#include <asm/pgtable.h> - -pte_t *kmemcheck_pte_lookup(unsigned long address); - -#endif diff --git a/arch/x86/mm/kmemcheck/selftest.c b/arch/x86/mm/kmemcheck/selftest.c index 7ce0be1f99eb..cec594032515 100644 --- a/arch/x86/mm/kmemcheck/selftest.c +++ b/arch/x86/mm/kmemcheck/selftest.c @@ -1,71 +1 @@ // SPDX-License-Identifier: GPL-2.0 -#include <linux/bug.h> -#include <linux/kernel.h> - -#include "opcode.h" -#include "selftest.h" - -struct selftest_opcode { - unsigned int expected_size; - const uint8_t *insn; - const char *desc; -}; - -static const struct selftest_opcode selftest_opcodes[] = { - /* REP MOVS */ - {1, "\xf3\xa4", "rep movsb <mem8>, <mem8>"}, - {4, "\xf3\xa5", "rep movsl <mem32>, <mem32>"}, - - /* MOVZX / MOVZXD */ - {1, "\x66\x0f\xb6\x51\xf8", "movzwq <mem8>, <reg16>"}, - {1, "\x0f\xb6\x51\xf8", "movzwq <mem8>, <reg32>"}, - - /* MOVSX / MOVSXD */ - {1, "\x66\x0f\xbe\x51\xf8", "movswq <mem8>, <reg16>"}, - {1, "\x0f\xbe\x51\xf8", "movswq <mem8>, <reg32>"}, - -#ifdef CONFIG_X86_64 - /* MOVZX / MOVZXD */ - {1, "\x49\x0f\xb6\x51\xf8", "movzbq <mem8>, <reg64>"}, - {2, "\x49\x0f\xb7\x51\xf8", "movzbq <mem16>, <reg64>"}, - - /* MOVSX / MOVSXD */ - {1, "\x49\x0f\xbe\x51\xf8", "movsbq <mem8>, <reg64>"}, - {2, "\x49\x0f\xbf\x51\xf8", "movsbq <mem16>, <reg64>"}, - {4, "\x49\x63\x51\xf8", "movslq <mem32>, <reg64>"}, -#endif -}; - -static bool selftest_opcode_one(const struct selftest_opcode *op) -{ - unsigned size; - - kmemcheck_opcode_decode(op->insn, &size); - - if (size == op->expected_size) - return true; - - printk(KERN_WARNING "kmemcheck: opcode %s: expected size %d, got %d\n", - op->desc, op->expected_size, size); - return false; -} - -static bool selftest_opcodes_all(void) -{ - bool pass = true; - unsigned int i; - - for (i = 0; i < ARRAY_SIZE(selftest_opcodes); ++i) - pass = pass && selftest_opcode_one(&selftest_opcodes[i]); - - return pass; -} - -bool kmemcheck_selftest(void) -{ - bool pass = true; - - pass = pass && selftest_opcodes_all(); - - return pass; -} diff --git a/arch/x86/mm/kmemcheck/selftest.h b/arch/x86/mm/kmemcheck/selftest.h index 8d759aae453d..ea32a7d3cf1b 100644 --- a/arch/x86/mm/kmemcheck/selftest.h +++ b/arch/x86/mm/kmemcheck/selftest.h @@ -1,7 +1 @@ /* SPDX-License-Identifier: GPL-2.0 */ -#ifndef ARCH_X86_MM_KMEMCHECK_SELFTEST_H -#define ARCH_X86_MM_KMEMCHECK_SELFTEST_H - -bool kmemcheck_selftest(void); - -#endif diff --git a/arch/x86/mm/kmemcheck/shadow.c b/arch/x86/mm/kmemcheck/shadow.c deleted file mode 100644 index c2638a7d2c10..000000000000 --- a/arch/x86/mm/kmemcheck/shadow.c +++ /dev/null @@ -1,173 +0,0 @@ -#include <linux/kmemcheck.h> -#include <linux/export.h> -#include <linux/mm.h> - -#include <asm/page.h> -#include <asm/pgtable.h> - -#include "pte.h" -#include "shadow.h" - -/* - * Return the shadow address for the given address. Returns NULL if the - * address is not tracked. - * - * We need to be extremely careful not to follow any invalid pointers, - * because this function can be called for *any* possible address. - */ -void *kmemcheck_shadow_lookup(unsigned long address) -{ - pte_t *pte; - struct page *page; - - if (!virt_addr_valid(address)) - return NULL; - - pte = kmemcheck_pte_lookup(address); - if (!pte) - return NULL; - - page = virt_to_page(address); - if (!page->shadow) - return NULL; - return page->shadow + (address & (PAGE_SIZE - 1)); -} - -static void mark_shadow(void *address, unsigned int n, - enum kmemcheck_shadow status) -{ - unsigned long addr = (unsigned long) address; - unsigned long last_addr = addr + n - 1; - unsigned long page = addr & PAGE_MASK; - unsigned long last_page = last_addr & PAGE_MASK; - unsigned int first_n; - void *shadow; - - /* If the memory range crosses a page boundary, stop there. */ - if (page == last_page) - first_n = n; - else - first_n = page + PAGE_SIZE - addr; - - shadow = kmemcheck_shadow_lookup(addr); - if (shadow) - memset(shadow, status, first_n); - - addr += first_n; - n -= first_n; - - /* Do full-page memset()s. */ - while (n >= PAGE_SIZE) { - shadow = kmemcheck_shadow_lookup(addr); - if (shadow) - memset(shadow, status, PAGE_SIZE); - - addr += PAGE_SIZE; - n -= PAGE_SIZE; - } - - /* Do the remaining page, if any. */ - if (n > 0) { - shadow = kmemcheck_shadow_lookup(addr); - if (shadow) - memset(shadow, status, n); - } -} - -void kmemcheck_mark_unallocated(void *address, unsigned int n) -{ - mark_shadow(address, n, KMEMCHECK_SHADOW_UNALLOCATED); -} - -void kmemcheck_mark_uninitialized(void *address, unsigned int n) -{ - mark_shadow(address, n, KMEMCHECK_SHADOW_UNINITIALIZED); -} - -/* - * Fill the shadow memory of the given address such that the memory at that - * address is marked as being initialized. - */ -void kmemcheck_mark_initialized(void *address, unsigned int n) -{ - mark_shadow(address, n, KMEMCHECK_SHADOW_INITIALIZED); -} -EXPORT_SYMBOL_GPL(kmemcheck_mark_initialized); - -void kmemcheck_mark_freed(void *address, unsigned int n) -{ - mark_shadow(address, n, KMEMCHECK_SHADOW_FREED); -} - -void kmemcheck_mark_unallocated_pages(struct page *p, unsigned int n) -{ - unsigned int i; - - for (i = 0; i < n; ++i) - kmemcheck_mark_unallocated(page_address(&p[i]), PAGE_SIZE); -} - -void kmemcheck_mark_uninitialized_pages(struct page *p, unsigned int n) -{ - unsigned int i; - - for (i = 0; i < n; ++i) - kmemcheck_mark_uninitialized(page_address(&p[i]), PAGE_SIZE); -} - -void kmemcheck_mark_initialized_pages(struct page *p, unsigned int n) -{ - unsigned int i; - - for (i = 0; i < n; ++i) - kmemcheck_mark_initialized(page_address(&p[i]), PAGE_SIZE); -} - -enum kmemcheck_shadow kmemcheck_shadow_test(void *shadow, unsigned int size) -{ -#ifdef CONFIG_KMEMCHECK_PARTIAL_OK - uint8_t *x; - unsigned int i; - - x = shadow; - - /* - * Make sure _some_ bytes are initialized. Gcc frequently generates - * code to access neighboring bytes. - */ - for (i = 0; i < size; ++i) { - if (x[i] == KMEMCHECK_SHADOW_INITIALIZED) - return x[i]; - } - - return x[0]; -#else - return kmemcheck_shadow_test_all(shadow, size); -#endif -} - -enum kmemcheck_shadow kmemcheck_shadow_test_all(void *shadow, unsigned int size) -{ - uint8_t *x; - unsigned int i; - - x = shadow; - - /* All bytes must be initialized. */ - for (i = 0; i < size; ++i) { - if (x[i] != KMEMCHECK_SHADOW_INITIALIZED) - return x[i]; - } - - return x[0]; -} - -void kmemcheck_shadow_set(void *shadow, unsigned int size) -{ - uint8_t *x; - unsigned int i; - - x = shadow; - for (i = 0; i < size; ++i) - x[i] = KMEMCHECK_SHADOW_INITIALIZED; -} diff --git a/arch/x86/mm/kmemcheck/shadow.h b/arch/x86/mm/kmemcheck/shadow.h index 49768dc18664..ea32a7d3cf1b 100644 --- a/arch/x86/mm/kmemcheck/shadow.h +++ b/arch/x86/mm/kmemcheck/shadow.h @@ -1,19 +1 @@ /* SPDX-License-Identifier: GPL-2.0 */ -#ifndef ARCH__X86__MM__KMEMCHECK__SHADOW_H -#define ARCH__X86__MM__KMEMCHECK__SHADOW_H - -enum kmemcheck_shadow { - KMEMCHECK_SHADOW_UNALLOCATED, - KMEMCHECK_SHADOW_UNINITIALIZED, - KMEMCHECK_SHADOW_INITIALIZED, - KMEMCHECK_SHADOW_FREED, -}; - -void *kmemcheck_shadow_lookup(unsigned long address); - -enum kmemcheck_shadow kmemcheck_shadow_test(void *shadow, unsigned int size); -enum kmemcheck_shadow kmemcheck_shadow_test_all(void *shadow, - unsigned int size); -void kmemcheck_shadow_set(void *shadow, unsigned int size); - -#endif |