Commit 4675ff05 authored by Levin, Alexander (Sasha Levin)'s avatar Levin, Alexander (Sasha Levin) Committed by Linus Torvalds

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.comSigned-off-by: default avatarSasha 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d8be7566
......@@ -1864,13 +1864,6 @@
Built with CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y,
the default is off.
kmemcheck= [X86] Boot-time kmemcheck enable/disable/one-shot mode
Valid arguments: 0, 1, 2
kmemcheck=0 (disabled)
kmemcheck=1 (enabled)
kmemcheck=2 (one-shot mode)
Default: 2 (one-shot mode)
kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.
Default is 0 (don't ignore, but inject #GP)
......
......@@ -21,7 +21,6 @@ whole; patches welcome!
kasan
ubsan
kmemleak
kmemcheck
gdb-kernel-debugging
kgdb
kselftest
......
This diff is collapsed.
......@@ -7688,16 +7688,6 @@ F: include/linux/kdb.h
F: include/linux/kgdb.h
F: kernel/debug/
KMEMCHECK
M: Vegard Nossum <vegardno@ifi.uio.no>
M: Pekka Enberg <penberg@kernel.org>
S: Maintained
F: Documentation/dev-tools/kmemcheck.rst
F: arch/x86/include/asm/kmemcheck.h
F: arch/x86/mm/kmemcheck/
F: include/linux/kmemcheck.h
F: mm/kmemcheck.c
KMEMLEAK
M: Catalin Marinas <catalin.marinas@arm.com>
S: Maintained
......
......@@ -112,7 +112,6 @@ config X86
select HAVE_ARCH_JUMP_LABEL
select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
select HAVE_ARCH_KGDB
select HAVE_ARCH_KMEMCHECK
select HAVE_ARCH_MMAP_RND_BITS if MMU
select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
......@@ -1430,7 +1429,7 @@ config ARCH_DMA_ADDR_T_64BIT
config X86_DIRECT_GBPAGES
def_bool y
depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
depends on X86_64 && !DEBUG_PAGEALLOC
---help---
Certain kernel features effectively disable kernel
linear 1 GB mappings (even if the CPU otherwise
......
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef ASM_X86_KMEMCHECK_H
#define ASM_X86_KMEMCHECK_H
#include <linux/types.h>
#include <asm/ptrace.h>
#ifdef CONFIG_KMEMCHECK
bool kmemcheck_active(struct pt_regs *regs);
void kmemcheck_show(struct pt_regs *regs);
void kmemcheck_hide(struct pt_regs *regs);
bool kmemcheck_fault(struct pt_regs *regs,
unsigned long address, unsigned long error_code);
bool kmemcheck_trap(struct pt_regs *regs);
#else
static inline bool kmemcheck_active(struct pt_regs *regs)
{
return false;
}
static inline void kmemcheck_show(struct pt_regs *regs)
{
}
static inline void kmemcheck_hide(struct pt_regs *regs)
{
}
static inline bool kmemcheck_fault(struct pt_regs *regs,
unsigned long address, unsigned long error_code)
{
return false;
}
static inline bool kmemcheck_trap(struct pt_regs *regs)
{
return false;
}
#endif /* CONFIG_KMEMCHECK */
#endif
......@@ -179,8 +179,6 @@ static inline void *__memcpy3d(void *to, const void *from, size_t len)
* No 3D Now!
*/
#ifndef CONFIG_KMEMCHECK
#if (__GNUC__ >= 4)
#define memcpy(t, f, n) __builtin_memcpy(t, f, n)
#else
......@@ -189,13 +187,6 @@ static inline void *__memcpy3d(void *to, const void *from, size_t len)
? __constant_memcpy((t), (f), (n)) \
: __memcpy((t), (f), (n)))
#endif
#else
/*
* kmemcheck becomes very happy if we use the REP instructions unconditionally,
* because it means that we know both memory operands in advance.
*/
#define memcpy(t, f, n) __memcpy((t), (f), (n))
#endif
#endif
#endif /* !CONFIG_FORTIFY_SOURCE */
......
......@@ -33,7 +33,6 @@ extern void *memcpy(void *to, const void *from, size_t len);
extern void *__memcpy(void *to, const void *from, size_t len);
#ifndef CONFIG_FORTIFY_SOURCE
#ifndef CONFIG_KMEMCHECK
#if (__GNUC__ == 4 && __GNUC_MINOR__ < 3) || __GNUC__ < 4
#define memcpy(dst, src, len) \
({ \
......@@ -46,13 +45,6 @@ extern void *__memcpy(void *to, const void *from, size_t len);
__ret; \
})
#endif
#else
/*
* kmemcheck becomes very happy if we use the REP instructions unconditionally,
* because it means that we know both memory operands in advance.
*/
#define memcpy(dst, src, len) __inline_memcpy((dst), (src), (len))
#endif
#endif /* !CONFIG_FORTIFY_SOURCE */
#define __HAVE_ARCH_MEMSET
......
......@@ -187,21 +187,6 @@ static void early_init_intel(struct cpuinfo_x86 *c)
if (c->x86 == 6 && c->x86_model < 15)
clear_cpu_cap(c, X86_FEATURE_PAT);
#ifdef CONFIG_KMEMCHECK
/*
* P4s have a "fast strings" feature which causes single-
* stepping REP instructions to only generate a #DB on
* cache-line boundaries.
*
* Ingo Molnar reported a Pentium D (model 6) and a Xeon
* (model 2) with the same problem.
*/
if (c->x86 == 15)
if (msr_clear_bit(MSR_IA32_MISC_ENABLE,
MSR_IA32_MISC_ENABLE_FAST_STRING_BIT) > 0)
pr_info("kmemcheck: Disabling fast string operations\n");
#endif
/*
* If fast string is not enabled in IA32_MISC_ENABLE for any reason,
* clear the fast string and enhanced fast string CPU capabilities.
......
......@@ -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
......
......@@ -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;
......
obj-y := error.o kmemcheck.o opcode.o pte.o selftest.o shadow.o
// 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);
}
/* 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
This diff is collapsed.
// 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;
}
/* 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
// 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;
}
/* 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
// 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;
}
/* 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
#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