[GIT PULL] x86 fixes

Ingo Molnar
2016-08-12T19:46:54Z

Linus,

Please pull the latest x86-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-for-linus

# HEAD: d52c0569bab4edc888832df44dc7ac28517134f6 x86/apic/x2apic, smp/hotplug: Don't use before alloc in x2apic_cluster_probe()

This is bigger than usual - the reason is partly a pent-up stream of fixes after
the merge window and partly accidental. The fixes are:

- 5 patches to fix a boot failure on Andy Lutomirsky's laptop.
- a KASAN fix
- 4 SGI UV platform fixes
- a warnings fix
- a documentation update
- a swap entry definition fix
- a pkeys fix
- an irq stats fix

Thanks,

Ingo

------------------>
Aaron Lu (1):
x86/irq: Do not substract irq_tlb_count from irq_call_count

Alexander Potapenko (1):
x86, kasan, ftrace: Put APIC interrupt handlers into .irqentry.text

Andy Lutomirski (5):
x86/boot: Run reserve_bios_regions() after we initialize the memory map
x86/boot: Synchronize trampoline_cr4_features and mmu_cr4_features directly
x86/boot: Defer setup_real_mode() to early_initcall time
x86/boot: Rework reserve_real_mode() to allow multiple tries
x86/efi: Allocate a trampoline if needed in efi_free_boot_services()

Borislav Petkov (1):
x86/entry: Clarify the RF saving/restoring situation with SYSCALL/SYSRET

Dave Hansen (2):
x86/mm/pkeys: Fix compact mode by removing protection keys' XSAVE buffer manipulation
x86/mm: Fix swap entry comment and macro

Mike Travis (4):
x86/platform/UV: Fix problem with UV4 Socket IDs not being contiguous
x86/platform/UV: Fix bug with iounmap() of the UV4 EFI System Table causing a crash
x86/platform/UV: Fix problem with UV4 BIOS providing incorrect PXM values
x86/platform/UV: Fix kernel panic running RHEL kdump kernel on UV systems

Nicolas Iooss (1):
x86/mm/kaslr: Fix -Wformat-security warning

Sebastian Andrzej Siewior (2):
x86/mm: Disable preemption during CR3 read+write
x86/apic/x2apic, smp/hotplug: Don't use before alloc in x2apic_cluster_probe()

Thomas Garnier (2):
x86/mm/KASLR: Fix physical memory calculation on KASLR memory randomization
x86/mm/KASLR: Increase BRK pages for KASLR memory randomization

Valdis Kletnieks (1):
x86/build: Reduce the W=1 warnings noise when compiling x86 syscall tables

arch/x86/entry/Makefile | 2 +
arch/x86/entry/entry_64.S | 25 ++++--
arch/x86/include/asm/hardirq.h | 4 -
arch/x86/include/asm/pgtable_64.h | 4 +-
arch/x86/include/asm/realmode.h | 10 ++-
arch/x86/include/asm/tlbflush.h | 7 ++
arch/x86/include/asm/uv/bios.h | 5 +-
arch/x86/kernel/apic/x2apic_cluster.c | 13 +++-
arch/x86/kernel/apic/x2apic_uv_x.c | 42 +++++------
arch/x86/kernel/fpu/xstate.c | 138 +++++-----------------------------
arch/x86/kernel/head32.c | 2 -
arch/x86/kernel/head64.c | 1 -
arch/x86/kernel/irq.c | 3 +-
arch/x86/kernel/setup.c | 27 ++++---
arch/x86/lib/kaslr.c | 2 +-
arch/x86/mm/init.c | 14 +++-
arch/x86/mm/kaslr.c | 2 +-
arch/x86/platform/efi/quirks.c | 21 ++++++
arch/x86/platform/uv/bios_uv.c | 8 +-
arch/x86/realmode/init.c | 47 +++++++++---
20 files changed, 182 insertions(+), 195 deletions(-)

diff --git a/arch/x86/entry/Makefile b/arch/x86/entry/Makefile
index fe91c25092da..77f28ce9c646 100644
--- a/arch/x86/entry/Makefile
+++ b/arch/x86/entry/Makefile
@@ -5,6 +5,8 @@
OBJECT_FILES_NON_STANDARD_entry_$(BITS).o := y
OBJECT_FILES_NON_STANDARD_entry_64_compat.o := y

+CFLAGS_syscall_64.o += -Wno-override-init
+CFLAGS_syscall_32.o += -Wno-override-init
obj-y := entry_$(BITS).o thunk_$(BITS).o syscall_$(BITS).o
obj-y += common.o

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index b846875aeea6..d172c619c449 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -288,11 +288,15 @@ GLOBAL(entry_SYSCALL_64_after_swapgs)
jne opportunistic_sysret_failed

/*
- * SYSRET can't restore RF. SYSRET can restore TF, but unlike IRET,
- * restoring TF results in a trap from userspace immediately after
- * SYSRET. This would cause an infinite loop whenever #DB happens
- * with register state that satisfies the opportunistic SYSRET
- * conditions. For example, single-stepping this user code:
+ * SYSCALL clears RF when it saves RFLAGS in R11 and SYSRET cannot
+ * restore RF properly. If the slowpath sets it for whatever reason, we
+ * need to restore it correctly.
+ *
+ * SYSRET can restore TF, but unlike IRET, restoring TF results in a
+ * trap from userspace immediately after SYSRET. This would cause an
+ * infinite loop whenever #DB happens with register state that satisfies
+ * the opportunistic SYSRET conditions. For example, single-stepping
+ * this user code:
*
* movq $stuck_here, %rcx
* pushfq
@@ -601,9 +605,20 @@ apicinterrupt3 \num trace(\sym) smp_trace(\sym)
.endm
#endif

+/* Make sure APIC interrupt handlers end up in the irqentry section: */
+#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
+# define PUSH_SECTION_IRQENTRY .pushsection .irqentry.text, "ax"
+# define POP_SECTION_IRQENTRY .popsection
+#else
+# define PUSH_SECTION_IRQENTRY
+# define POP_SECTION_IRQENTRY
+#endif
+
.macro apicinterrupt num sym do_sym
+PUSH_SECTION_IRQENTRY
apicinterrupt3 \num \sym \do_sym
trace_apicinterrupt \num \sym
+POP_SECTION_IRQENTRY
.endm

#ifdef CONFIG_SMP
diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h
index 7178043b0e1d..59405a248fc2 100644
--- a/arch/x86/include/asm/hardirq.h
+++ b/arch/x86/include/asm/hardirq.h
@@ -22,10 +22,6 @@ typedef struct {
#ifdef CONFIG_SMP
unsigned int irq_resched_count;
unsigned int irq_call_count;
- /*
- * irq_tlb_count is double-counted in irq_call_count, so it must be
- * subtracted from irq_call_count when displaying irq_call_count
- */
unsigned int irq_tlb_count;
#endif
#ifdef CONFIG_X86_THERMAL_VECTOR
diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index 7e8ec7ae10fa..1cc82ece9ac1 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -145,7 +145,7 @@ static inline int pgd_large(pgd_t pgd) { return 0; }
*
* | ... | 11| 10| 9|8|7|6|5| 4| 3|2|1|0| <- bit number
* | ... |SW3|SW2|SW1|G|L|D|A|CD|WT|U|W|P| <- bit names
- * | OFFSET (14->63) | TYPE (10-13) |0|X|X|X| X| X|X|X|0| <- swp entry
+ * | OFFSET (14->63) | TYPE (9-13) |0|X|X|X| X| X|X|X|0| <- swp entry
*
* G (8) is aliased and used as a PROT_NONE indicator for
* !present ptes. We need to start storing swap entries above
@@ -156,7 +156,7 @@ static inline int pgd_large(pgd_t pgd) { return 0; }
#define SWP_TYPE_FIRST_BIT (_PAGE_BIT_PROTNONE + 1)
#define SWP_TYPE_BITS 5
/* Place the offset above the type: */
-#define SWP_OFFSET_FIRST_BIT (SWP_TYPE_FIRST_BIT + SWP_TYPE_BITS + 1)
+#define SWP_OFFSET_FIRST_BIT (SWP_TYPE_FIRST_BIT + SWP_TYPE_BITS)

#define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS)

diff --git a/arch/x86/include/asm/realmode.h b/arch/x86/include/asm/realmode.h
index 9c6b890d5e7a..b2988c0ed829 100644
--- a/arch/x86/include/asm/realmode.h
+++ b/arch/x86/include/asm/realmode.h
@@ -58,7 +58,15 @@ extern unsigned char boot_gdt[];
extern unsigned char secondary_startup_64[];
#endif

+static inline size_t real_mode_size_needed(void)
+{
+ if (real_mode_header)
+ return 0; /* already allocated. */
+
+ return ALIGN(real_mode_blob_end - real_mode_blob, PAGE_SIZE);
+}
+
+void set_real_mode_mem(phys_addr_t mem, size_t size);
void reserve_real_mode(void);
-void setup_real_mode(void);

#endif /* _ARCH_X86_REALMODE_H */
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index 4e5be94e079a..6fa85944af83 100644
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -135,7 +135,14 @@ static inline void cr4_set_bits_and_update_boot(unsigned long mask)

static inline void __native_flush_tlb(void)
{
+ /*
+ * If current->mm == NULL then we borrow a mm which may change during a
+ * task switch and therefore we must not be preempted while we write CR3
+ * back:
+ */
+ preempt_disable();
native_write_cr3(native_read_cr3());
+ preempt_enable();
}

static inline void __native_flush_tlb_global_irq_disabled(void)
diff --git a/arch/x86/include/asm/uv/bios.h b/arch/x86/include/asm/uv/bios.h
index c852590254d5..e652a7cc6186 100644
--- a/arch/x86/include/asm/uv/bios.h
+++ b/arch/x86/include/asm/uv/bios.h
@@ -79,7 +79,7 @@ struct uv_gam_range_entry {
u16 nasid; /* HNasid */
u16 sockid; /* Socket ID, high bits of APIC ID */
u16 pnode; /* Index to MMR and GRU spaces */
- u32 pxm; /* ACPI proximity domain number */
+ u32 unused2;
u32 limit; /* PA bits 56:26 (UV_GAM_RANGE_SHFT) */
};

@@ -88,7 +88,8 @@ struct uv_gam_range_entry {
#define UV_SYSTAB_VERSION_UV4 0x400 /* UV4 BIOS base version */
#define UV_SYSTAB_VERSION_UV4_1 0x401 /* + gpa_shift */
#define UV_SYSTAB_VERSION_UV4_2 0x402 /* + TYPE_NVRAM/WINDOW/MBOX */
-#define UV_SYSTAB_VERSION_UV4_LATEST UV_SYSTAB_VERSION_UV4_2
+#define UV_SYSTAB_VERSION_UV4_3 0x403 /* - GAM Range PXM Value */
+#define UV_SYSTAB_VERSION_UV4_LATEST UV_SYSTAB_VERSION_UV4_3

#define UV_SYSTAB_TYPE_UNUSED 0 /* End of table (offset == 0) */
#define UV_SYSTAB_TYPE_GAM_PARAMS 1 /* GAM PARAM conversions */
diff --git a/arch/x86/kernel/apic/x2apic_cluster.c b/arch/x86/kernel/apic/x2apic_cluster.c
index 6368fa69d2af..54f35d988025 100644
--- a/arch/x86/kernel/apic/x2apic_cluster.c
+++ b/arch/x86/kernel/apic/x2apic_cluster.c
@@ -155,7 +155,7 @@ static void init_x2apic_ldr(void)
/*
* At CPU state changes, update the x2apic cluster sibling info.
*/
-int x2apic_prepare_cpu(unsigned int cpu)
+static int x2apic_prepare_cpu(unsigned int cpu)
{
if (!zalloc_cpumask_var(&per_cpu(cpus_in_cluster, cpu), GFP_KERNEL))
return -ENOMEM;
@@ -168,7 +168,7 @@ int x2apic_prepare_cpu(unsigned int cpu)
return 0;
}

-int x2apic_dead_cpu(unsigned int this_cpu)
+static int x2apic_dead_cpu(unsigned int this_cpu)
{
int cpu;

@@ -186,13 +186,18 @@ int x2apic_dead_cpu(unsigned int this_cpu)
static int x2apic_cluster_probe(void)
{
int cpu = smp_processor_id();
+ int ret;

if (!x2apic_mode)
return 0;

+ ret = cpuhp_setup_state(CPUHP_X2APIC_PREPARE, "X2APIC_PREPARE",
+ x2apic_prepare_cpu, x2apic_dead_cpu);
+ if (ret < 0) {
+ pr_err("Failed to register X2APIC_PREPARE\n");
+ return 0;
+ }
cpumask_set_cpu(cpu, per_cpu(cpus_in_cluster, cpu));
- cpuhp_setup_state(CPUHP_X2APIC_PREPARE, "X2APIC_PREPARE",
- x2apic_prepare_cpu, x2apic_dead_cpu);
return 1;
}

diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index 09b59adaea3f..cb0673c1e940 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -223,6 +223,11 @@ static int __init uv_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
if (strncmp(oem_id, "SGI", 3) != 0)
return 0;

+ if (numa_off) {
+ pr_err("UV: NUMA is off, disabling UV support\n");
+ return 0;
+ }
+
/* Setup early hub type field in uv_hub_info for Node 0 */
uv_cpu_info->p_uv_hub_info = &uv_hub_info_node0;

@@ -325,7 +330,7 @@ static __init void build_uv_gr_table(void)
struct uv_gam_range_entry *gre = uv_gre_table;
struct uv_gam_range_s *grt;
unsigned long last_limit = 0, ram_limit = 0;
- int bytes, i, sid, lsid = -1;
+ int bytes, i, sid, lsid = -1, indx = 0, lindx = -1;

if (!gre)
return;
@@ -356,11 +361,12 @@ static __init void build_uv_gr_table(void)
}
sid = gre->sockid - _min_socket;
if (lsid < sid) { /* new range */
- grt = &_gr_table[sid];
- grt->base = lsid;
+ grt = &_gr_table[indx];
+ grt->base = lindx;
grt->nasid = gre->nasid;
grt->limit = last_limit = gre->limit;
lsid = sid;
+ lindx = indx++;
continue;
}
if (lsid == sid && !ram_limit) { /* update range */
@@ -371,7 +377,7 @@ static __init void build_uv_gr_table(void)
}
if (!ram_limit) { /* non-contiguous ram range */
grt++;
- grt->base = sid - 1;
+ grt->base = lindx;
grt->nasid = gre->nasid;
grt->limit = last_limit = gre->limit;
continue;
@@ -1155,19 +1161,18 @@ static void __init decode_gam_rng_tbl(unsigned long ptr)
for (; gre->type != UV_GAM_RANGE_TYPE_UNUSED; gre++) {
if (!index) {
pr_info("UV: GAM Range Table...\n");
- pr_info("UV: # %20s %14s %5s %4s %5s %3s %2s %3s\n",
+ pr_info("UV: # %20s %14s %5s %4s %5s %3s %2s\n",
"Range", "", "Size", "Type", "NASID",
- "SID", "PN", "PXM");
+ "SID", "PN");
}
pr_info(
- "UV: %2d: 0x%014lx-0x%014lx %5luG %3d %04x %02x %02x %3d\n",
+ "UV: %2d: 0x%014lx-0x%014lx %5luG %3d %04x %02x %02x\n",
index++,
(unsigned long)lgre << UV_GAM_RANGE_SHFT,
(unsigned long)gre->limit << UV_GAM_RANGE_SHFT,
((unsigned long)(gre->limit - lgre)) >>
(30 - UV_GAM_RANGE_SHFT), /* 64M -> 1G */
- gre->type, gre->nasid, gre->sockid,
- gre->pnode, gre->pxm);
+ gre->type, gre->nasid, gre->sockid, gre->pnode);

lgre = gre->limit;
if (sock_min > gre->sockid)
@@ -1286,7 +1291,7 @@ static void __init build_socket_tables(void)
_pnode_to_socket[i] = SOCK_EMPTY;

/* fill in pnode/node/addr conversion list values */
- pr_info("UV: GAM Building socket/pnode/pxm conversion tables\n");
+ pr_info("UV: GAM Building socket/pnode conversion tables\n");
for (; gre->type != UV_GAM_RANGE_TYPE_UNUSED; gre++) {
if (gre->type == UV_GAM_RANGE_TYPE_HOLE)
continue;
@@ -1294,20 +1299,18 @@ static void __init build_socket_tables(void)
if (_socket_to_pnode[i] != SOCK_EMPTY)
continue; /* duplicate */
_socket_to_pnode[i] = gre->pnode;
- _socket_to_node[i] = gre->pxm;

i = gre->pnode - minpnode;
_pnode_to_socket[i] = gre->sockid;

pr_info(
- "UV: sid:%02x type:%d nasid:%04x pn:%02x pxm:%2d pn2s:%2x\n",
+ "UV: sid:%02x type:%d nasid:%04x pn:%02x pn2s:%2x\n",
gre->sockid, gre->type, gre->nasid,
_socket_to_pnode[gre->sockid - minsock],
- _socket_to_node[gre->sockid - minsock],
_pnode_to_socket[gre->pnode - minpnode]);
}

- /* check socket -> node values */
+ /* Set socket -> node values */
lnid = -1;
for_each_present_cpu(cpu) {
int nid = cpu_to_node(cpu);
@@ -1318,14 +1321,9 @@ static void __init build_socket_tables(void)
lnid = nid;
apicid = per_cpu(x86_cpu_to_apicid, cpu);
sockid = apicid >> uv_cpuid.socketid_shift;
- i = sockid - minsock;
-
- if (nid != _socket_to_node[i]) {
- pr_warn(
- "UV: %02x: type:%d socket:%02x PXM:%02x != node:%2d\n",
- i, sockid, gre->type, _socket_to_node[i], nid);
- _socket_to_node[i] = nid;
- }
+ _socket_to_node[sockid - minsock] = nid;
+ pr_info("UV: sid:%02x: apicid:%04x node:%2d\n",
+ sockid, apicid, nid);
}

/* Setup physical blade to pnode translation from GAM Range Table */
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 680049aa4593..01567aa87503 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -866,105 +866,17 @@ const void *get_xsave_field_ptr(int xsave_state)
return get_xsave_addr(&fpu->state.xsave, xsave_state);
}

-
-/*
- * Set xfeatures (aka XSTATE_BV) bit for a feature that we want
- * to take out of its "init state". This will ensure that an
- * XRSTOR actually restores the state.
- */
-static void fpu__xfeature_set_non_init(struct xregs_state *xsave,
- int xstate_feature_mask)
-{
- xsave->header.xfeatures |= xstate_feature_mask;
-}
-
-/*
- * This function is safe to call whether the FPU is in use or not.
- *
- * Note that this only works on the current task.
- *
- * Inputs:
- * @xsave_state: state which is defined in xsave.h (e.g. XFEATURE_MASK_FP,
- * XFEATURE_MASK_SSE, etc...)
- * @xsave_state_ptr: a pointer to a copy of the state that you would
- * like written in to the current task's FPU xsave state. This pointer
- * must not be located in the current tasks's xsave area.
- * Output:
- * address of the state in the xsave area or NULL if the state
- * is not present or is in its 'init state'.
- */
-static void fpu__xfeature_set_state(int xstate_feature_mask,
- void *xstate_feature_src, size_t len)
-{
- struct xregs_state *xsave = &current->thread.fpu.state.xsave;
- struct fpu *fpu = &current->thread.fpu;
- void *dst;
-
- if (!boot_cpu_has(X86_FEATURE_XSAVE)) {
- WARN_ONCE(1, "%s() attempted with no xsave support", __func__);
- return;
- }
-
- /*
- * Tell the FPU code that we need the FPU state to be in
- * 'fpu' (not in the registers), and that we need it to
- * be stable while we write to it.
- */
- fpu__current_fpstate_write_begin();
-
- /*
- * This method *WILL* *NOT* work for compact-format
- * buffers. If the 'xstate_feature_mask' is unset in
- * xcomp_bv then we may need to move other feature state
- * "up" in the buffer.
- */
- if (xsave->header.xcomp_bv & xstate_feature_mask) {
- WARN_ON_ONCE(1);
- goto out;
- }
-
- /* find the location in the xsave buffer of the desired state */
- dst = __raw_xsave_addr(&fpu->state.xsave, xstate_feature_mask);
-
- /*
- * Make sure that the pointer being passed in did not
- * come from the xsave buffer itself.
- */
- WARN_ONCE(xstate_feature_src == dst, "set from xsave buffer itself");
-
- /* put the caller-provided data in the location */
- memcpy(dst, xstate_feature_src, len);
-
- /*
- * Mark the xfeature so that the CPU knows there is state
- * in the buffer now.
- */
- fpu__xfeature_set_non_init(xsave, xstate_feature_mask);
-out:
- /*
- * We are done writing to the 'fpu'. Reenable preeption
- * and (possibly) move the fpstate back in to the fpregs.
- */
- fpu__current_fpstate_write_end();
-}
-
#define NR_VALID_PKRU_BITS (CONFIG_NR_PROTECTION_KEYS * 2)
#define PKRU_VALID_MASK (NR_VALID_PKRU_BITS - 1)

/*
- * This will go out and modify the XSAVE buffer so that PKRU is
- * set to a particular state for access to 'pkey'.
- *
- * PKRU state does affect kernel access to user memory. We do
- * not modfiy PKRU *itself* here, only the XSAVE state that will
- * be restored in to PKRU when we return back to userspace.
+ * This will go out and modify PKRU register to set the access
+ * rights for @pkey to @init_val.
*/
int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
unsigned long init_val)
{
- struct xregs_state *xsave = &tsk->thread.fpu.state.xsave;
- struct pkru_state *old_pkru_state;
- struct pkru_state new_pkru_state;
+ u32 old_pkru;
int pkey_shift = (pkey * PKRU_BITS_PER_PKEY);
u32 new_pkru_bits = 0;

@@ -974,6 +886,15 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
*/
if (!boot_cpu_has(X86_FEATURE_OSPKE))
return -EINVAL;
+ /*
+ * For most XSAVE components, this would be an arduous task:
+ * brining fpstate up to date with fpregs, updating fpstate,
+ * then re-populating fpregs. But, for components that are
+ * never lazily managed, we can just access the fpregs
+ * directly. PKRU is never managed lazily, so we can just
+ * manipulate it directly. Make sure it stays that way.
+ */
+ WARN_ON_ONCE(!use_eager_fpu());

/* Set the bits we need in PKRU: */
if (init_val & PKEY_DISABLE_ACCESS)
@@ -984,37 +905,12 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
/* Shift the bits in to the correct place in PKRU for pkey: */
new_pkru_bits <<= pkey_shift;

- /* Locate old copy of the state in the xsave buffer: */
- old_pkru_state = get_xsave_addr(xsave, XFEATURE_MASK_PKRU);
-
- /*
- * When state is not in the buffer, it is in the init
- * state, set it manually. Otherwise, copy out the old
- * state.
- */
- if (!old_pkru_state)
- new_pkru_state.pkru = 0;
- else
- new_pkru_state.pkru = old_pkru_state->pkru;
-
- /* Mask off any old bits in place: */
- new_pkru_state.pkru &= ~((PKRU_AD_BIT|PKRU_WD_BIT) << pkey_shift);
-
- /* Set the newly-requested bits: */
- new_pkru_state.pkru |= new_pkru_bits;
-
- /*
- * We could theoretically live without zeroing pkru.pad.
- * The current XSAVE feature state definition says that
- * only bytes 0->3 are used. But we do not want to
- * chance leaking kernel stack out to userspace in case a
- * memcpy() of the whole xsave buffer was done.
- *
- * They're in the same cacheline anyway.
- */
- new_pkru_state.pad = 0;
+ /* Get old PKRU and mask off any old bits in place: */
+ old_pkru = read_pkru();
+ old_pkru &= ~((PKRU_AD_BIT|PKRU_WD_BIT) << pkey_shift);

- fpu__xfeature_set_state(XFEATURE_MASK_PKRU, &new_pkru_state, sizeof(new_pkru_state));
+ /* Write old part along with new part: */
+ write_pkru(old_pkru | new_pkru_bits);

return 0;
}
diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c
index 2dda0bc4576e..f16c55bfc090 100644
--- a/arch/x86/kernel/head32.c
+++ b/arch/x86/kernel/head32.c
@@ -25,8 +25,6 @@ static void __init i386_default_early_setup(void)
/* Initialize 32bit specific setup functions */
x86_init.resources.reserve_resources = i386_reserve_resources;
x86_init.mpparse.setup_ioapic_ids = setup_ioapic_ids_from_mpc;
-
- reserve_bios_regions();
}

asmlinkage __visible void __init i386_start_kernel(void)
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 99d48e7d2974..54a2372f5dbb 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -183,7 +183,6 @@ void __init x86_64_start_reservations(char *real_mode_data)
copy_bootdata(__va(real_mode_data));

x86_early_init_platform_quirks();
- reserve_bios_regions();

switch (boot_params.hdr.hardware_subarch) {
case X86_SUBARCH_INTEL_MID:
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 61521dc19c10..9f669fdd2010 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -102,8 +102,7 @@ int arch_show_interrupts(struct seq_file *p, int prec)
seq_puts(p, " Rescheduling interrupts\n");
seq_printf(p, "%*s: ", prec, "CAL");
for_each_online_cpu(j)
- seq_printf(p, "%10u ", irq_stats(j)->irq_call_count -
- irq_stats(j)->irq_tlb_count);
+ seq_printf(p, "%10u ", irq_stats(j)->irq_call_count);
seq_puts(p, " Function call interrupts\n");
seq_printf(p, "%*s: ", prec, "TLB");
for_each_online_cpu(j)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 991b77986d57..0fa60f5f5a16 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -936,8 +936,6 @@ void __init setup_arch(char **cmdline_p)

x86_init.oem.arch_setup();

- kernel_randomize_memory();
-
iomem_resource.end = (1ULL << boot_cpu_data.x86_phys_bits) - 1;
setup_memory_map();
parse_setup_data();
@@ -1055,6 +1053,12 @@ void __init setup_arch(char **cmdline_p)

max_possible_pfn = max_pfn;

+ /*
+ * Define random base addresses for memory sections after max_pfn is
+ * defined and before each memory section base is used.
+ */
+ kernel_randomize_memory();
+
#ifdef CONFIG_X86_32
/* max_low_pfn get updated here */
find_low_pfn_range();
@@ -1097,6 +1101,8 @@ void __init setup_arch(char **cmdline_p)
efi_find_mirror();
}

+ reserve_bios_regions();
+
/*
* The EFI specification says that boot service code won't be called
* after ExitBootServices(). This is, in fact, a lie.
@@ -1125,7 +1131,15 @@ void __init setup_arch(char **cmdline_p)

early_trap_pf_init();

- setup_real_mode();
+ /*
+ * Update mmu_cr4_features (and, indirectly, trampoline_cr4_features)
+ * with the current CR4 value. This may not be necessary, but
+ * auditing all the early-boot CR4 manipulation would be needed to
+ * rule it out.
+ */
+ if (boot_cpu_data.cpuid_level >= 0)
+ /* A CPU has %cr4 if and only if it has CPUID. */
+ mmu_cr4_features = __read_cr4();

memblock_set_current_limit(get_max_mapped());

@@ -1174,13 +1188,6 @@ void __init setup_arch(char **cmdline_p)

kasan_init();

- if (boot_cpu_data.cpuid_level >= 0) {
- /* A CPU has %cr4 if and only if it has CPUID */
- mmu_cr4_features = __read_cr4();
- if (trampoline_cr4_features)
- *trampoline_cr4_features = mmu_cr4_features;
- }
-
#ifdef CONFIG_X86_32
/* sync back kernel address range */
clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY,
diff --git a/arch/x86/lib/kaslr.c b/arch/x86/lib/kaslr.c
index f7dfeda83e5c..121f59c6ee54 100644
--- a/arch/x86/lib/kaslr.c
+++ b/arch/x86/lib/kaslr.c
@@ -19,7 +19,7 @@
#include <asm/cpufeature.h>
#include <asm/setup.h>

-#define debug_putstr(v) early_printk(v)
+#define debug_putstr(v) early_printk("%s", v)
#define has_cpuflag(f) boot_cpu_has(f)
#define get_boot_seed() kaslr_offset()
#endif
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 620928903be3..d28a2d741f9e 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -122,8 +122,18 @@ __ref void *alloc_low_pages(unsigned int num)
return __va(pfn << PAGE_SHIFT);
}

-/* need 3 4k for initial PMD_SIZE, 3 4k for 0-ISA_END_ADDRESS */
-#define INIT_PGT_BUF_SIZE (6 * PAGE_SIZE)
+/*
+ * By default need 3 4k for initial PMD_SIZE, 3 4k for 0-ISA_END_ADDRESS.
+ * With KASLR memory randomization, depending on the machine e820 memory
+ * and the PUD alignment. We may need twice more pages when KASLR memory
+ * randomization is enabled.
+ */
+#ifndef CONFIG_RANDOMIZE_MEMORY
+#define INIT_PGD_PAGE_COUNT 6
+#else
+#define INIT_PGD_PAGE_COUNT 12
+#endif
+#define INIT_PGT_BUF_SIZE (INIT_PGD_PAGE_COUNT * PAGE_SIZE)
RESERVE_BRK(early_pgt_alloc, INIT_PGT_BUF_SIZE);
void __init early_alloc_pgt_buf(void)
{
diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c
index 26dccd6c0df1..ec8654f117d8 100644
--- a/arch/x86/mm/kaslr.c
+++ b/arch/x86/mm/kaslr.c
@@ -97,7 +97,7 @@ void __init kernel_randomize_memory(void)
* add padding if needed (especially for memory hotplug support).
*/
BUG_ON(kaslr_regions[0].base != &page_offset_base);
- memory_tb = ((max_pfn << PAGE_SHIFT) >> TB_SHIFT) +
+ memory_tb = DIV_ROUND_UP(max_pfn << PAGE_SHIFT, 1UL << TB_SHIFT) +
CONFIG_RANDOMIZE_MEMORY_PHYSICAL_PADDING;

/* Adapt phyiscal memory region size based on available memory */
diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index 4480c06cade7..89d1146f5a6f 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -254,6 +254,7 @@ void __init efi_free_boot_services(void)
for_each_efi_memory_desc(md) {
unsigned long long start = md->phys_addr;
unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
+ size_t rm_size;

if (md->type != EFI_BOOT_SERVICES_CODE &&
md->type != EFI_BOOT_SERVICES_DATA)
@@ -263,6 +264,26 @@ void __init efi_free_boot_services(void)
if (md->attribute & EFI_MEMORY_RUNTIME)
continue;

+ /*
+ * Nasty quirk: if all sub-1MB memory is used for boot
+ * services, we can get here without having allocated the
+ * real mode trampoline. It's too late to hand boot services
+ * memory back to the memblock allocator, so instead
+ * try to manually allocate the trampoline if needed.
+ *
+ * I've seen this on a Dell XPS 13 9350 with firmware
+ * 1.4.4 with SGX enabled booting Linux via Fedora 24's
+ * grub2-efi on a hard disk. (And no, I don't know why
+ * this happened, but Linux should still try to boot rather
+ * panicing early.)
+ */
+ rm_size = real_mode_size_needed();
+ if (rm_size && (start + rm_size) < (1<<20) && size >= rm_size) {
+ set_real_mode_mem(start, rm_size);
+ start += rm_size;
+ size -= rm_size;
+ }
+
free_bootmem_late(start, size);
}

diff --git a/arch/x86/platform/uv/bios_uv.c b/arch/x86/platform/uv/bios_uv.c
index 66b2166ea4a1..4e9fd1378aec 100644
--- a/arch/x86/platform/uv/bios_uv.c
+++ b/arch/x86/platform/uv/bios_uv.c
@@ -199,12 +199,14 @@ void uv_bios_init(void)
return;
}

+ /* Starting with UV4 the UV systab size is variable */
if (uv_systab->revision >= UV_SYSTAB_VERSION_UV4) {
+ int size = uv_systab->size;
+
iounmap(uv_systab);
- uv_systab = ioremap(efi.uv_systab, uv_systab->size);
+ uv_systab = ioremap(efi.uv_systab, size);
if (!uv_systab) {
- pr_err("UV: UVsystab: ioremap(%d) failed!\n",
- uv_systab->size);
+ pr_err("UV: UVsystab: ioremap(%d) failed!\n", size);
return;
}
}
diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
index 705e3fffb4a1..5db706f14111 100644
--- a/arch/x86/realmode/init.c
+++ b/arch/x86/realmode/init.c
@@ -1,9 +1,11 @@
#include <linux/io.h>
+#include <linux/slab.h>
#include <linux/memblock.h>

#include <asm/cacheflush.h>
#include <asm/pgtable.h>
#include <asm/realmode.h>
+#include <asm/tlbflush.h>

struct real_mode_header *real_mode_header;
u32 *trampoline_cr4_features;
@@ -11,25 +13,37 @@ u32 *trampoline_cr4_features;
/* Hold the pgd entry used on booting additional CPUs */
pgd_t trampoline_pgd_entry;

+void __init set_real_mode_mem(phys_addr_t mem, size_t size)
+{
+ void *base = __va(mem);
+
+ real_mode_header = (struct real_mode_header *) base;
+ printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n",
+ base, (unsigned long long)mem, size);
+}
+
void __init reserve_real_mode(void)
{
phys_addr_t mem;
- unsigned char *base;
- size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
+ size_t size = real_mode_size_needed();
+
+ if (!size)
+ return;
+
+ WARN_ON(slab_is_available());

/* Has to be under 1M so we can execute real-mode AP code. */
mem = memblock_find_in_range(0, 1<<20, size, PAGE_SIZE);
- if (!mem)
- panic("Cannot allocate trampoline\n");
+ if (!mem) {
+ pr_info("No sub-1M memory is available for the trampoline\n");
+ return;
+ }

- base = __va(mem);
memblock_reserve(mem, size);
- real_mode_header = (struct real_mode_header *) base;
- printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n",
- base, (unsigned long long)mem, size);
+ set_real_mode_mem(mem, size);
}

-void __init setup_real_mode(void)
+static void __init setup_real_mode(void)
{
u16 real_mode_seg;
const u32 *rel;
@@ -84,7 +98,7 @@ void __init setup_real_mode(void)

trampoline_header->start = (u64) secondary_startup_64;
trampoline_cr4_features = &trampoline_header->cr4;
- *trampoline_cr4_features = __read_cr4();
+ *trampoline_cr4_features = mmu_cr4_features;

trampoline_pgd = (u64 *) __va(real_mode_header->trampoline_pgd);
trampoline_pgd[0] = trampoline_pgd_entry.pgd;
@@ -100,7 +114,7 @@ void __init setup_real_mode(void)
* need to mark it executable at do_pre_smp_initcalls() at least,
* thus run it as a early_initcall().
*/
-static int __init set_real_mode_permissions(void)
+static void __init set_real_mode_permissions(void)
{
unsigned char *base = (unsigned char *) real_mode_header;
size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
@@ -119,7 +133,16 @@ static int __init set_real_mode_permissions(void)
set_memory_nx((unsigned long) base, size >> PAGE_SHIFT);
set_memory_ro((unsigned long) base, ro_size >> PAGE_SHIFT);
set_memory_x((unsigned long) text_start, text_size >> PAGE_SHIFT);
+}
+
+static int __init init_real_mode(void)
+{
+ if (!real_mode_header)
+ panic("Real mode trampoline was not allocated");
+
+ setup_real_mode();
+ set_real_mode_permissions();

return 0;
}
-early_initcall(set_real_mode_permissions);
+early_initcall(init_real_mode);