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authorLinus Torvalds <torvalds@linux-foundation.org>2014-08-05 00:15:45 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-05 00:15:45 (GMT)
commitce4747963252a30613ebf1c1df3d83b9526a342e (patch)
tree6c61d1b1045a72965006324ae3805280be296e53 /arch
parent76f09aa464a1913efd596dd0edbf88f932fde08c (diff)
parenta5102476a24bce364b74f1110005542a2c964103 (diff)
downloadlinux-ce4747963252a30613ebf1c1df3d83b9526a342e.tar.xz
Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm changes from Ingo Molnar: "The main change in this cycle is the rework of the TLB range flushing code, to simplify, fix and consolidate the code. By Dave Hansen" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Set TLB flush tunable to sane value (33) x86/mm: New tunable for single vs full TLB flush x86/mm: Add tracepoints for TLB flushes x86/mm: Unify remote INVLPG code x86/mm: Fix missed global TLB flush stat x86/mm: Rip out complicated, out-of-date, buggy TLB flushing x86/mm: Clean up the TLB flushing code x86/smep: Be more informative when signalling an SMEP fault
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/mmu_context.h6
-rw-r--r--arch/x86/include/asm/processor.h1
-rw-r--r--arch/x86/kernel/cpu/amd.c7
-rw-r--r--arch/x86/kernel/cpu/common.c13
-rw-r--r--arch/x86/kernel/cpu/intel.c26
-rw-r--r--arch/x86/mm/fault.c6
-rw-r--r--arch/x86/mm/init.c7
-rw-r--r--arch/x86/mm/tlb.c103
8 files changed, 70 insertions, 99 deletions
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index be12c53..166af2a 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -3,6 +3,10 @@
#include <asm/desc.h>
#include <linux/atomic.h>
+#include <linux/mm_types.h>
+
+#include <trace/events/tlb.h>
+
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#include <asm/paravirt.h>
@@ -44,6 +48,7 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
/* Re-load page tables */
load_cr3(next->pgd);
+ trace_tlb_flush(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL);
/* Stop flush ipis for the previous mm */
cpumask_clear_cpu(cpu, mm_cpumask(prev));
@@ -71,6 +76,7 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
* to make sure to use no freed page tables.
*/
load_cr3(next->pgd);
+ trace_tlb_flush(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL);
load_LDT_nolock(&next->context);
}
}
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 32cc237..ee30b9f 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -72,7 +72,6 @@ extern u16 __read_mostly tlb_lld_4k[NR_INFO];
extern u16 __read_mostly tlb_lld_2m[NR_INFO];
extern u16 __read_mostly tlb_lld_4m[NR_INFO];
extern u16 __read_mostly tlb_lld_1g[NR_INFO];
-extern s8 __read_mostly tlb_flushall_shift;
/*
* CPU type and hardware bug flags. Kept separately for each CPU.
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index bc360d3..60e5497 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -724,11 +724,6 @@ static unsigned int amd_size_cache(struct cpuinfo_x86 *c, unsigned int size)
}
#endif
-static void cpu_set_tlb_flushall_shift(struct cpuinfo_x86 *c)
-{
- tlb_flushall_shift = 6;
-}
-
static void cpu_detect_tlb_amd(struct cpuinfo_x86 *c)
{
u32 ebx, eax, ecx, edx;
@@ -776,8 +771,6 @@ static void cpu_detect_tlb_amd(struct cpuinfo_x86 *c)
tlb_lli_2m[ENTRIES] = eax & mask;
tlb_lli_4m[ENTRIES] = tlb_lli_2m[ENTRIES] >> 1;
-
- cpu_set_tlb_flushall_shift(c);
}
static const struct cpu_dev amd_cpu_dev = {
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 188a8c5..333fd52 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -481,26 +481,17 @@ u16 __read_mostly tlb_lld_2m[NR_INFO];
u16 __read_mostly tlb_lld_4m[NR_INFO];
u16 __read_mostly tlb_lld_1g[NR_INFO];
-/*
- * tlb_flushall_shift shows the balance point in replacing cr3 write
- * with multiple 'invlpg'. It will do this replacement when
- * flush_tlb_lines <= active_lines/2^tlb_flushall_shift.
- * If tlb_flushall_shift is -1, means the replacement will be disabled.
- */
-s8 __read_mostly tlb_flushall_shift = -1;
-
void cpu_detect_tlb(struct cpuinfo_x86 *c)
{
if (this_cpu->c_detect_tlb)
this_cpu->c_detect_tlb(c);
printk(KERN_INFO "Last level iTLB entries: 4KB %d, 2MB %d, 4MB %d\n"
- "Last level dTLB entries: 4KB %d, 2MB %d, 4MB %d, 1GB %d\n"
- "tlb_flushall_shift: %d\n",
+ "Last level dTLB entries: 4KB %d, 2MB %d, 4MB %d, 1GB %d\n",
tlb_lli_4k[ENTRIES], tlb_lli_2m[ENTRIES],
tlb_lli_4m[ENTRIES], tlb_lld_4k[ENTRIES],
tlb_lld_2m[ENTRIES], tlb_lld_4m[ENTRIES],
- tlb_lld_1g[ENTRIES], tlb_flushall_shift);
+ tlb_lld_1g[ENTRIES]);
}
void detect_ht(struct cpuinfo_x86 *c)
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 9483ee5..74e804d 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -634,31 +634,6 @@ static void intel_tlb_lookup(const unsigned char desc)
}
}
-static void intel_tlb_flushall_shift_set(struct cpuinfo_x86 *c)
-{
- switch ((c->x86 << 8) + c->x86_model) {
- case 0x60f: /* original 65 nm celeron/pentium/core2/xeon, "Merom"/"Conroe" */
- case 0x616: /* single-core 65 nm celeron/core2solo "Merom-L"/"Conroe-L" */
- case 0x617: /* current 45 nm celeron/core2/xeon "Penryn"/"Wolfdale" */
- case 0x61d: /* six-core 45 nm xeon "Dunnington" */
- tlb_flushall_shift = -1;
- break;
- case 0x63a: /* Ivybridge */
- tlb_flushall_shift = 2;
- break;
- case 0x61a: /* 45 nm nehalem, "Bloomfield" */
- case 0x61e: /* 45 nm nehalem, "Lynnfield" */
- case 0x625: /* 32 nm nehalem, "Clarkdale" */
- case 0x62c: /* 32 nm nehalem, "Gulftown" */
- case 0x62e: /* 45 nm nehalem-ex, "Beckton" */
- case 0x62f: /* 32 nm Xeon E7 */
- case 0x62a: /* SandyBridge */
- case 0x62d: /* SandyBridge, "Romely-EP" */
- default:
- tlb_flushall_shift = 6;
- }
-}
-
static void intel_detect_tlb(struct cpuinfo_x86 *c)
{
int i, j, n;
@@ -683,7 +658,6 @@ static void intel_detect_tlb(struct cpuinfo_x86 *c)
for (j = 1 ; j < 16 ; j++)
intel_tlb_lookup(desc[j]);
}
- intel_tlb_flushall_shift_set(c);
}
static const struct cpu_dev intel_cpu_dev = {
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 3664279..1dbade8 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -577,6 +577,8 @@ static int is_f00f_bug(struct pt_regs *regs, unsigned long address)
static const char nx_warning[] = KERN_CRIT
"kernel tried to execute NX-protected page - exploit attempt? (uid: %d)\n";
+static const char smep_warning[] = KERN_CRIT
+"unable to execute userspace code (SMEP?) (uid: %d)\n";
static void
show_fault_oops(struct pt_regs *regs, unsigned long error_code,
@@ -597,6 +599,10 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code,
if (pte && pte_present(*pte) && !pte_exec(*pte))
printk(nx_warning, from_kuid(&init_user_ns, current_uid()));
+ if (pte && pte_present(*pte) && pte_exec(*pte) &&
+ (pgd_flags(*pgd) & _PAGE_USER) &&
+ (read_cr4() & X86_CR4_SMEP))
+ printk(smep_warning, from_kuid(&init_user_ns, current_uid()));
}
printk(KERN_ALERT "BUG: unable to handle kernel ");
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index f971306..66dba36 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -18,6 +18,13 @@
#include <asm/dma.h> /* for MAX_DMA_PFN */
#include <asm/microcode.h>
+/*
+ * We need to define the tracepoints somewhere, and tlb.c
+ * is only compied when SMP=y.
+ */
+#define CREATE_TRACE_POINTS
+#include <trace/events/tlb.h>
+
#include "mm_internal.h"
static unsigned long __initdata pgt_buf_start;
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index dd8dda1..1fe3398 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -49,6 +49,7 @@ void leave_mm(int cpu)
if (cpumask_test_cpu(cpu, mm_cpumask(active_mm))) {
cpumask_clear_cpu(cpu, mm_cpumask(active_mm));
load_cr3(swapper_pg_dir);
+ trace_tlb_flush(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL);
}
}
EXPORT_SYMBOL_GPL(leave_mm);
@@ -102,20 +103,24 @@ static void flush_tlb_func(void *info)
if (f->flush_mm != this_cpu_read(cpu_tlbstate.active_mm))
return;
+ if (!f->flush_end)
+ f->flush_end = f->flush_start + PAGE_SIZE;
count_vm_tlb_event(NR_TLB_REMOTE_FLUSH_RECEIVED);
if (this_cpu_read(cpu_tlbstate.state) == TLBSTATE_OK) {
- if (f->flush_end == TLB_FLUSH_ALL)
+ if (f->flush_end == TLB_FLUSH_ALL) {
local_flush_tlb();
- else if (!f->flush_end)
- __flush_tlb_single(f->flush_start);
- else {
+ trace_tlb_flush(TLB_REMOTE_SHOOTDOWN, TLB_FLUSH_ALL);
+ } else {
unsigned long addr;
+ unsigned long nr_pages =
+ f->flush_end - f->flush_start / PAGE_SIZE;
addr = f->flush_start;
while (addr < f->flush_end) {
__flush_tlb_single(addr);
addr += PAGE_SIZE;
}
+ trace_tlb_flush(TLB_REMOTE_SHOOTDOWN, nr_pages);
}
} else
leave_mm(smp_processor_id());
@@ -153,46 +158,45 @@ void flush_tlb_current_task(void)
count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
local_flush_tlb();
+ trace_tlb_flush(TLB_LOCAL_SHOOTDOWN, TLB_FLUSH_ALL);
if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids)
flush_tlb_others(mm_cpumask(mm), mm, 0UL, TLB_FLUSH_ALL);
preempt_enable();
}
+/*
+ * See Documentation/x86/tlb.txt for details. We choose 33
+ * because it is large enough to cover the vast majority (at
+ * least 95%) of allocations, and is small enough that we are
+ * confident it will not cause too much overhead. Each single
+ * flush is about 100 ns, so this caps the maximum overhead at
+ * _about_ 3,000 ns.
+ *
+ * This is in units of pages.
+ */
+unsigned long tlb_single_page_flush_ceiling = 33;
+
void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
unsigned long end, unsigned long vmflag)
{
unsigned long addr;
- unsigned act_entries, tlb_entries = 0;
- unsigned long nr_base_pages;
+ /* do a global flush by default */
+ unsigned long base_pages_to_flush = TLB_FLUSH_ALL;
preempt_disable();
if (current->active_mm != mm)
- goto flush_all;
+ goto out;
if (!current->mm) {
leave_mm(smp_processor_id());
- goto flush_all;
+ goto out;
}
- if (end == TLB_FLUSH_ALL || tlb_flushall_shift == -1
- || vmflag & VM_HUGETLB) {
- local_flush_tlb();
- goto flush_all;
- }
-
- /* In modern CPU, last level tlb used for both data/ins */
- if (vmflag & VM_EXEC)
- tlb_entries = tlb_lli_4k[ENTRIES];
- else
- tlb_entries = tlb_lld_4k[ENTRIES];
+ if ((end != TLB_FLUSH_ALL) && !(vmflag & VM_HUGETLB))
+ base_pages_to_flush = (end - start) >> PAGE_SHIFT;
- /* Assume all of TLB entries was occupied by this task */
- act_entries = tlb_entries >> tlb_flushall_shift;
- act_entries = mm->total_vm > act_entries ? act_entries : mm->total_vm;
- nr_base_pages = (end - start) >> PAGE_SHIFT;
-
- /* tlb_flushall_shift is on balance point, details in commit log */
- if (nr_base_pages > act_entries) {
+ if (base_pages_to_flush > tlb_single_page_flush_ceiling) {
+ base_pages_to_flush = TLB_FLUSH_ALL;
count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
local_flush_tlb();
} else {
@@ -201,17 +205,15 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ONE);
__flush_tlb_single(addr);
}
-
- if (cpumask_any_but(mm_cpumask(mm),
- smp_processor_id()) < nr_cpu_ids)
- flush_tlb_others(mm_cpumask(mm), mm, start, end);
- preempt_enable();
- return;
}
-
-flush_all:
+ trace_tlb_flush(TLB_LOCAL_MM_SHOOTDOWN, base_pages_to_flush);
+out:
+ if (base_pages_to_flush == TLB_FLUSH_ALL) {
+ start = 0UL;
+ end = TLB_FLUSH_ALL;
+ }
if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids)
- flush_tlb_others(mm_cpumask(mm), mm, 0UL, TLB_FLUSH_ALL);
+ flush_tlb_others(mm_cpumask(mm), mm, start, end);
preempt_enable();
}
@@ -260,32 +262,26 @@ static void do_kernel_range_flush(void *info)
void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
- unsigned act_entries;
- struct flush_tlb_info info;
-
- /* In modern CPU, last level tlb used for both data/ins */
- act_entries = tlb_lld_4k[ENTRIES];
/* Balance as user space task's flush, a bit conservative */
- if (end == TLB_FLUSH_ALL || tlb_flushall_shift == -1 ||
- (end - start) >> PAGE_SHIFT > act_entries >> tlb_flushall_shift)
-
+ if (end == TLB_FLUSH_ALL ||
+ (end - start) > tlb_single_page_flush_ceiling * PAGE_SIZE) {
on_each_cpu(do_flush_tlb_all, NULL, 1);
- else {
+ } else {
+ struct flush_tlb_info info;
info.flush_start = start;
info.flush_end = end;
on_each_cpu(do_kernel_range_flush, &info, 1);
}
}
-#ifdef CONFIG_DEBUG_TLBFLUSH
static ssize_t tlbflush_read_file(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
char buf[32];
unsigned int len;
- len = sprintf(buf, "%hd\n", tlb_flushall_shift);
+ len = sprintf(buf, "%ld\n", tlb_single_page_flush_ceiling);
return simple_read_from_buffer(user_buf, count, ppos, buf, len);
}
@@ -294,20 +290,20 @@ static ssize_t tlbflush_write_file(struct file *file,
{
char buf[32];
ssize_t len;
- s8 shift;
+ int ceiling;
len = min(count, sizeof(buf) - 1);
if (copy_from_user(buf, user_buf, len))
return -EFAULT;
buf[len] = '\0';
- if (kstrtos8(buf, 0, &shift))
+ if (kstrtoint(buf, 0, &ceiling))
return -EINVAL;
- if (shift < -1 || shift >= BITS_PER_LONG)
+ if (ceiling < 0)
return -EINVAL;
- tlb_flushall_shift = shift;
+ tlb_single_page_flush_ceiling = ceiling;
return count;
}
@@ -317,11 +313,10 @@ static const struct file_operations fops_tlbflush = {
.llseek = default_llseek,
};
-static int __init create_tlb_flushall_shift(void)
+static int __init create_tlb_single_page_flush_ceiling(void)
{
- debugfs_create_file("tlb_flushall_shift", S_IRUSR | S_IWUSR,
+ debugfs_create_file("tlb_single_page_flush_ceiling", S_IRUSR | S_IWUSR,
arch_debugfs_dir, NULL, &fops_tlbflush);
return 0;
}
-late_initcall(create_tlb_flushall_shift);
-#endif
+late_initcall(create_tlb_single_page_flush_ceiling);