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: e5dce2868818ca8706924f7bdc7939d481eefab0 x86/platform/intel-mid: 
Rename platform_wdt to platform_mrfld_wdt

Misc fixes:

 - two fixes to make (very) old Intel CPUs boot reliably
 - fix the intel-mid driver and rename it
 - two KASAN false positive fixes
 - an FPU fix
 - two sysfb fixes
 - two build fixes related to new toolchain versions

 Thanks,

        Ingo

------------------>
Andy Lutomirski (2):
      x86/traps: Ignore high word of regs->cs in early_fixup_exception()
      x86/boot: Fail the boot if !M486 and CPUID is missing

Andy Shevchenko (2):
      x86/platform/intel-mid: Register watchdog device after SCU
      x86/platform/intel-mid: Rename platform_wdt to platform_mrfld_wdt

Arnd Bergmann (1):
      x86/boot: Avoid warning for zero-filling .bss

David Herrmann (2):
      x86/sysfb: Add support for 64bit EFI lfb_base
      x86/sysfb: Fix lfb_size calculation

H.J. Lu (1):
      x86/build: Build compressed x86 kernels as PIE when !CONFIG_RELOCATABLE 
as well

Josh Poimboeuf (2):
      x86/unwind: Prevent KASAN false positive warnings in guess unwinder
      x86/dumpstack: Prevent KASAN false positive warnings

Yu-cheng Yu (1):
      x86/fpu: Fix invalid FPU ptrace state after execve()


 arch/x86/boot/compressed/Makefile                  |  5 ++-
 arch/x86/boot/cpu.c                                |  6 ++++
 arch/x86/kernel/dumpstack.c                        |  2 +-
 arch/x86/kernel/fpu/core.c                         | 16 ++++-----
 arch/x86/kernel/head_32.S                          |  9 +++--
 arch/x86/kernel/sysfb_simplefb.c                   | 39 +++++++++++++++++-----
 arch/x86/kernel/unwind_guess.c                     |  8 +++--
 arch/x86/mm/extable.c                              |  7 +++-
 arch/x86/platform/intel-mid/device_libs/Makefile   |  2 +-
 .../{platform_wdt.c => platform_mrfld_wdt.c}       | 34 +++++++++++++++----
 10 files changed, 95 insertions(+), 33 deletions(-)
 rename arch/x86/platform/intel-mid/device_libs/{platform_wdt.c => 
platform_mrfld_wdt.c} (65%)

diff --git a/arch/x86/boot/compressed/Makefile 
b/arch/x86/boot/compressed/Makefile
index 536ccfcc01c6..34d9e15857c3 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -40,8 +40,8 @@ GCOV_PROFILE := n
 UBSAN_SANITIZE :=n
 
 LDFLAGS := -m elf_$(UTS_MACHINE)
-ifeq ($(CONFIG_RELOCATABLE),y)
-# If kernel is relocatable, build compressed kernel as PIE.
+# Compressed kernel should be built as PIE since it may be loaded at any
+# address by the bootloader.
 ifeq ($(CONFIG_X86_32),y)
 LDFLAGS += $(call ld-option, -pie) $(call ld-option, --no-dynamic-linker)
 else
@@ -51,7 +51,6 @@ else
 LDFLAGS += $(shell $(LD) --help 2>&1 | grep -q "\-z noreloc-overflow" \
        && echo "-z noreloc-overflow -pie --no-dynamic-linker")
 endif
-endif
 LDFLAGS_vmlinux := -T
 
 hostprogs-y    := mkpiggy
diff --git a/arch/x86/boot/cpu.c b/arch/x86/boot/cpu.c
index 26240dde081e..4224ede43b4e 100644
--- a/arch/x86/boot/cpu.c
+++ b/arch/x86/boot/cpu.c
@@ -87,6 +87,12 @@ int validate_cpu(void)
                return -1;
        }
 
+       if (CONFIG_X86_MINIMUM_CPU_FAMILY <= 4 && !IS_ENABLED(CONFIG_M486) &&
+           !has_eflag(X86_EFLAGS_ID)) {
+               printf("This kernel requires a CPU with the CPUID instruction.  
Build with CONFIG_M486=y to run on this CPU.\n");
+               return -1;
+       }
+
        if (err_flags) {
                puts("This kernel requires the following features "
                     "not present on the CPU:\n");
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 9b7cf5c28f5f..85f854b98a9d 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -112,7 +112,7 @@ void show_trace_log_lvl(struct task_struct *task, struct 
pt_regs *regs,
                for (; stack < stack_info.end; stack++) {
                        unsigned long real_addr;
                        int reliable = 0;
-                       unsigned long addr = *stack;
+                       unsigned long addr = READ_ONCE_NOCHECK(*stack);
                        unsigned long *ret_addr_p =
                                unwind_get_return_address_ptr(&state);
 
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 47004010ad5d..ebb4e95fbd74 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -521,14 +521,14 @@ void fpu__clear(struct fpu *fpu)
 {
        WARN_ON_FPU(fpu != &current->thread.fpu); /* Almost certainly an 
anomaly */
 
-       if (!use_eager_fpu() || !static_cpu_has(X86_FEATURE_FPU)) {
-               /* FPU state will be reallocated lazily at the first use. */
-               fpu__drop(fpu);
-       } else {
-               if (!fpu->fpstate_active) {
-                       fpu__activate_curr(fpu);
-                       user_fpu_begin();
-               }
+       fpu__drop(fpu);
+
+       /*
+        * Make sure fpstate is cleared and initialized.
+        */
+       if (static_cpu_has(X86_FEATURE_FPU)) {
+               fpu__activate_curr(fpu);
+               user_fpu_begin();
                copy_init_fpstate_to_fpregs();
        }
 }
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index b6b2f0264af3..2dabea46f039 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -665,14 +665,17 @@ __PAGE_ALIGNED_BSS
 initial_pg_pmd:
        .fill 1024*KPMDS,4,0
 #else
-ENTRY(initial_page_table)
+.globl initial_page_table
+initial_page_table:
        .fill 1024,4,0
 #endif
 initial_pg_fixmap:
        .fill 1024,4,0
-ENTRY(empty_zero_page)
+.globl empty_zero_page
+empty_zero_page:
        .fill 4096,1,0
-ENTRY(swapper_pg_dir)
+.globl swapper_pg_dir
+swapper_pg_dir:
        .fill 1024,4,0
 EXPORT_SYMBOL(empty_zero_page)
 
diff --git a/arch/x86/kernel/sysfb_simplefb.c b/arch/x86/kernel/sysfb_simplefb.c
index 764a29f84de7..85195d447a92 100644
--- a/arch/x86/kernel/sysfb_simplefb.c
+++ b/arch/x86/kernel/sysfb_simplefb.c
@@ -66,13 +66,36 @@ __init int create_simplefb(const struct screen_info *si,
 {
        struct platform_device *pd;
        struct resource res;
-       unsigned long len;
+       u64 base, size;
+       u32 length;
 
-       /* don't use lfb_size as it may contain the whole VMEM instead of only
-        * the part that is occupied by the framebuffer */
-       len = mode->height * mode->stride;
-       len = PAGE_ALIGN(len);
-       if (len > (u64)si->lfb_size << 16) {
+       /*
+        * If the 64BIT_BASE capability is set, ext_lfb_base will contain the
+        * upper half of the base address. Assemble the address, then make sure
+        * it is valid and we can actually access it.
+        */
+       base = si->lfb_base;
+       if (si->capabilities & VIDEO_CAPABILITY_64BIT_BASE)
+               base |= (u64)si->ext_lfb_base << 32;
+       if (!base || (u64)(resource_size_t)base != base) {
+               printk(KERN_DEBUG "sysfb: inaccessible VRAM base\n");
+               return -EINVAL;
+       }
+
+       /*
+        * Don't use lfb_size as IORESOURCE size, since it may contain the
+        * entire VMEM, and thus require huge mappings. Use just the part we
+        * need, that is, the part where the framebuffer is located. But verify
+        * that it does not exceed the advertised VMEM.
+        * Note that in case of VBE, the lfb_size is shifted by 16 bits for
+        * historical reasons.
+        */
+       size = si->lfb_size;
+       if (si->orig_video_isVGA == VIDEO_TYPE_VLFB)
+               size <<= 16;
+       length = mode->height * mode->stride;
+       length = PAGE_ALIGN(length);
+       if (length > size) {
                printk(KERN_WARNING "sysfb: VRAM smaller than advertised\n");
                return -EINVAL;
        }
@@ -81,8 +104,8 @@ __init int create_simplefb(const struct screen_info *si,
        memset(&res, 0, sizeof(res));
        res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
        res.name = simplefb_resname;
-       res.start = si->lfb_base;
-       res.end = si->lfb_base + len - 1;
+       res.start = base;
+       res.end = res.start + length - 1;
        if (res.end <= res.start)
                return -EINVAL;
 
diff --git a/arch/x86/kernel/unwind_guess.c b/arch/x86/kernel/unwind_guess.c
index 2d721e533cf4..b80e8bf43cc6 100644
--- a/arch/x86/kernel/unwind_guess.c
+++ b/arch/x86/kernel/unwind_guess.c
@@ -7,11 +7,13 @@
 
 unsigned long unwind_get_return_address(struct unwind_state *state)
 {
+       unsigned long addr = READ_ONCE_NOCHECK(*state->sp);
+
        if (unwind_done(state))
                return 0;
 
        return ftrace_graph_ret_addr(state->task, &state->graph_idx,
-                                    *state->sp, state->sp);
+                                    addr, state->sp);
 }
 EXPORT_SYMBOL_GPL(unwind_get_return_address);
 
@@ -23,8 +25,10 @@ bool unwind_next_frame(struct unwind_state *state)
                return false;
 
        do {
+               unsigned long addr = READ_ONCE_NOCHECK(*state->sp);
+
                for (state->sp++; state->sp < info->end; state->sp++)
-                       if (__kernel_text_address(*state->sp))
+                       if (__kernel_text_address(addr))
                                return true;
 
                state->sp = info->next_sp;
diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
index 79ae939970d3..fcd06f7526de 100644
--- a/arch/x86/mm/extable.c
+++ b/arch/x86/mm/extable.c
@@ -135,7 +135,12 @@ void __init early_fixup_exception(struct pt_regs *regs, 
int trapnr)
        if (early_recursion_flag > 2)
                goto halt_loop;
 
-       if (regs->cs != __KERNEL_CS)
+       /*
+        * Old CPUs leave the high bits of CS on the stack
+        * undefined.  I'm not sure which CPUs do this, but at least
+        * the 486 DX works this way.
+        */
+       if ((regs->cs & 0xFFFF) != __KERNEL_CS)
                goto fail;
 
        /*
diff --git a/arch/x86/platform/intel-mid/device_libs/Makefile 
b/arch/x86/platform/intel-mid/device_libs/Makefile
index 429d08be7848..dd6cfa4ad3ac 100644
--- a/arch/x86/platform/intel-mid/device_libs/Makefile
+++ b/arch/x86/platform/intel-mid/device_libs/Makefile
@@ -28,4 +28,4 @@ obj-$(subst m,y,$(CONFIG_GPIO_PCA953X)) += 
platform_pcal9555a.o
 obj-$(subst m,y,$(CONFIG_GPIO_PCA953X)) += platform_tca6416.o
 # MISC Devices
 obj-$(subst m,y,$(CONFIG_KEYBOARD_GPIO)) += platform_gpio_keys.o
-obj-$(subst m,y,$(CONFIG_INTEL_MID_WATCHDOG)) += platform_wdt.o
+obj-$(subst m,y,$(CONFIG_INTEL_MID_WATCHDOG)) += platform_mrfld_wdt.o
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_wdt.c 
b/arch/x86/platform/intel-mid/device_libs/platform_mrfld_wdt.c
similarity index 65%
rename from arch/x86/platform/intel-mid/device_libs/platform_wdt.c
rename to arch/x86/platform/intel-mid/device_libs/platform_mrfld_wdt.c
index de734134bc8d..3f1f1c77d090 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_wdt.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_mrfld_wdt.c
@@ -1,5 +1,5 @@
 /*
- * platform_wdt.c: Watchdog platform library file
+ * Intel Merrifield watchdog platform device library file
  *
  * (C) Copyright 2014 Intel Corporation
  * Author: David Cohen <[email protected]>
@@ -14,7 +14,9 @@
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include <linux/platform_data/intel-mid_wdt.h>
+
 #include <asm/intel-mid.h>
+#include <asm/intel_scu_ipc.h>
 #include <asm/io_apic.h>
 
 #define TANGIER_EXT_TIMER0_MSI 15
@@ -50,14 +52,34 @@ static struct intel_mid_wdt_pdata tangier_pdata = {
        .probe = tangier_probe,
 };
 
-static int __init register_mid_wdt(void)
+static int wdt_scu_status_change(struct notifier_block *nb,
+                                unsigned long code, void *data)
 {
-       if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER) {
-               wdt_dev.dev.platform_data = &tangier_pdata;
-               return platform_device_register(&wdt_dev);
+       if (code == SCU_DOWN) {
+               platform_device_unregister(&wdt_dev);
+               return 0;
        }
 
-       return -ENODEV;
+       return platform_device_register(&wdt_dev);
 }
 
+static struct notifier_block wdt_scu_notifier = {
+       .notifier_call  = wdt_scu_status_change,
+};
+
+static int __init register_mid_wdt(void)
+{
+       if (intel_mid_identify_cpu() != INTEL_MID_CPU_CHIP_TANGIER)
+               return -ENODEV;
+
+       wdt_dev.dev.platform_data = &tangier_pdata;
+
+       /*
+        * We need to be sure that the SCU IPC is ready before watchdog device
+        * can be registered:
+        */
+       intel_scu_notifier_add(&wdt_scu_notifier);
+
+       return 0;
+}
 rootfs_initcall(register_mid_wdt);

Reply via email to