[GIT PULL] x86 fixes

Ingo Molnar
2018-11-30T06:29:14Z

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: 60c8144afc287ef09ce8c1230c6aa972659ba1bb x86/MCE/AMD: Fix the thresholding machinery initialization order

Misc fixes:

- an MCE related boot crash fix on certain AMD systems
- an FPU exception handling fix
- an FPU handling race fix
- a revert+rewrite of the RSDP boot protocol extension, use boot_params
instead
- a documentation fix

Thanks,

Ingo

------------------>
Borislav Petkov (1):
x86/MCE/AMD: Fix the thresholding machinery initialization order

Elvira Khabirova (1):
x86/ptrace: Fix documentation for tracehook_report_syscall_entry()

Jann Horn (1):
x86/fpu: Use the correct exception table macro in the XSTATE_OP wrapper

Juergen Gross (2):
x86/boot: Mostly revert commit ae7e1238e68f2a ("Add ACPI RSDP address to setup_header")
x86/acpi, x86/boot: Take RSDP address from boot params if available

Sebastian Andrzej Siewior (1):
x86/fpu: Disable bottom halves while loading FPU registers

Documentation/x86/boot.txt | 32 +-------------------------------
arch/x86/boot/header.S | 6 +-----
arch/x86/include/asm/fpu/internal.h | 2 +-
arch/x86/include/asm/x86_init.h | 2 --
arch/x86/include/uapi/asm/bootparam.h | 7 ++-----
arch/x86/kernel/acpi/boot.c | 2 +-
arch/x86/kernel/cpu/mcheck/mce_amd.c | 19 ++++++-------------
arch/x86/kernel/fpu/signal.c | 4 ++--
arch/x86/kernel/head32.c | 1 -
arch/x86/kernel/head64.c | 2 --
arch/x86/kernel/setup.c | 17 -----------------
include/linux/tracehook.h | 4 ++--
12 files changed, 16 insertions(+), 82 deletions(-)

diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt
index 7727db8f94bc..5e9b826b5f62 100644
--- a/Documentation/x86/boot.txt
+++ b/Documentation/x86/boot.txt
@@ -61,18 +61,6 @@ Protocol 2.12: (Kernel 3.8) Added the xloadflags field and extension fields
to struct boot_params for loading bzImage and ramdisk
above 4G in 64bit.

-Protocol 2.13: (Kernel 3.14) Support 32- and 64-bit flags being set in
- xloadflags to support booting a 64-bit kernel from 32-bit
- EFI
-
-Protocol 2.14: (Kernel 4.20) Added acpi_rsdp_addr holding the physical
- address of the ACPI RSDP table.
- The bootloader updates version with:
- 0x8000 | min(kernel-version, bootloader-version)
- kernel-version being the protocol version supported by
- the kernel and bootloader-version the protocol version
- supported by the bootloader.
-
**** MEMORY LAYOUT

The traditional memory map for the kernel loader, used for Image or
@@ -209,7 +197,6 @@ Offset Proto Name Meaning
0258/8 2.10+ pref_address Preferred loading address
0260/4 2.10+ init_size Linear memory required during initialization
0264/4 2.11+ handover_offset Offset of handover entry point
-0268/8 2.14+ acpi_rsdp_addr Physical address of RSDP table

(1) For backwards compatibility, if the setup_sects field contains 0, the
real value is 4.
@@ -322,7 +309,7 @@ Protocol: 2.00+
Contains the magic number "HdrS" (0x53726448).

Field name: version
-Type: modify
+Type: read
Offset/size: 0x206/2
Protocol: 2.00+

@@ -330,12 +317,6 @@ Protocol: 2.00+
e.g. 0x0204 for version 2.04, and 0x0a11 for a hypothetical version
10.17.

- Up to protocol version 2.13 this information is only read by the
- bootloader. From protocol version 2.14 onwards the bootloader will
- write the used protocol version or-ed with 0x8000 to the field. The
- used protocol version will be the minimum of the supported protocol
- versions of the bootloader and the kernel.
-
Field name: realmode_swtch
Type: modify (optional)
Offset/size: 0x208/4
@@ -763,17 +744,6 @@ Offset/size: 0x264/4

See EFI HANDOVER PROTOCOL below for more details.

-Field name: acpi_rsdp_addr
-Type: write
-Offset/size: 0x268/8
-Protocol: 2.14+
-
- This field can be set by the boot loader to tell the kernel the
- physical address of the ACPI RSDP table.
-
- A value of 0 indicates the kernel should fall back to the standard
- methods to locate the RSDP.
-

**** THE IMAGE CHECKSUM

diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 4c881c850125..850b8762e889 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -300,7 +300,7 @@ _start:
# Part 2 of the header, from the old setup.S

.ascii "HdrS" # header signature
- .word 0x020e # header version number (>= 0x0105)
+ .word 0x020d # header version number (>= 0x0105)
# or else old loadlin-1.5 will fail)
.globl realmode_swtch
realmode_swtch: .word 0, 0 # default_switch, SETUPSEG
@@ -558,10 +558,6 @@ pref_address: .quad LOAD_PHYSICAL_ADDR # preferred load addr
init_size: .long INIT_SIZE # kernel initialization size
handover_offset: .long 0 # Filled in by build.c

-acpi_rsdp_addr: .quad 0 # 64-bit physical pointer to the
- # ACPI RSDP table, added with
- # version 2.14
-
# End of setup header #####################################################

.section ".entrytext", "ax"
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index 5f7290e6e954..69dcdf195b61 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -226,7 +226,7 @@ static inline void copy_fxregs_to_kernel(struct fpu *fpu)
"3: movl $-2,%[err]\n\t" \
"jmp 2b\n\t" \
".popsection\n\t" \
- _ASM_EXTABLE_UA(1b, 3b) \
+ _ASM_EXTABLE(1b, 3b) \
: [err] "=r" (err) \
: "D" (st), "m" (*st), "a" (lmask), "d" (hmask) \
: "memory")
diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index 0f842104862c..b85a7c54c6a1 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -303,6 +303,4 @@ extern void x86_init_noop(void);
extern void x86_init_uint_noop(unsigned int unused);
extern bool x86_pnpbios_disabled(void);

-void x86_verify_bootdata_version(void);
-
#endif
diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
index 22f89d040ddd..60733f137e9a 100644
--- a/arch/x86/include/uapi/asm/bootparam.h
+++ b/arch/x86/include/uapi/asm/bootparam.h
@@ -16,9 +16,6 @@
#define RAMDISK_PROMPT_FLAG 0x8000
#define RAMDISK_LOAD_FLAG 0x4000

-/* version flags */
-#define VERSION_WRITTEN 0x8000
-
/* loadflags */
#define LOADED_HIGH (1<<0)
#define KASLR_FLAG (1<<1)
@@ -89,7 +86,6 @@ struct setup_header {
__u64 pref_address;
__u32 init_size;
__u32 handover_offset;
- __u64 acpi_rsdp_addr;
} __attribute__((packed));

struct sys_desc_table {
@@ -159,7 +155,8 @@ struct boot_params {
__u8 _pad2[4]; /* 0x054 */
__u64 tboot_addr; /* 0x058 */
struct ist_info ist_info; /* 0x060 */
- __u8 _pad3[16]; /* 0x070 */
+ __u64 acpi_rsdp_addr; /* 0x070 */
+ __u8 _pad3[8]; /* 0x078 */
__u8 hd0_info[16]; /* obsolete! */ /* 0x080 */
__u8 hd1_info[16]; /* obsolete! */ /* 0x090 */
struct sys_desc_table sys_desc_table; /* obsolete! */ /* 0x0a0 */
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 92c76bf97ad8..06635fbca81c 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1776,5 +1776,5 @@ void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size)

u64 x86_default_get_root_pointer(void)
{
- return boot_params.hdr.acpi_rsdp_addr;
+ return boot_params.acpi_rsdp_addr;
}
diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c
index dd33c357548f..e12454e21b8a 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
@@ -56,7 +56,7 @@
/* Threshold LVT offset is at MSR0xC0000410[15:12] */
#define SMCA_THR_LVT_OFF 0xF000

-static bool thresholding_en;
+static bool thresholding_irq_en;

static const char * const th_names[] = {
"load_store",
@@ -534,9 +534,8 @@ prepare_threshold_block(unsigned int bank, unsigned int block, u32 addr,

set_offset:
offset = setup_APIC_mce_threshold(offset, new);
-
- if ((offset == new) && (mce_threshold_vector != amd_threshold_interrupt))
- mce_threshold_vector = amd_threshold_interrupt;
+ if (offset == new)
+ thresholding_irq_en = true;

done:
mce_threshold_block_init(&b, offset);
@@ -1357,9 +1356,6 @@ int mce_threshold_remove_device(unsigned int cpu)
{
unsigned int bank;

- if (!thresholding_en)
- return 0;
-
for (bank = 0; bank < mca_cfg.banks; ++bank) {
if (!(per_cpu(bank_map, cpu) & (1 << bank)))
continue;
@@ -1377,9 +1373,6 @@ int mce_threshold_create_device(unsigned int cpu)
struct threshold_bank **bp;
int err = 0;

- if (!thresholding_en)
- return 0;
-
bp = per_cpu(threshold_banks, cpu);
if (bp)
return 0;
@@ -1408,9 +1401,6 @@ static __init int threshold_init_device(void)
{
unsigned lcpu = 0;

- if (mce_threshold_vector == amd_threshold_interrupt)
- thresholding_en = true;
-
/* to hit CPUs online before the notifier is up */
for_each_online_cpu(lcpu) {
int err = mce_threshold_create_device(lcpu);
@@ -1419,6 +1409,9 @@ static __init int threshold_init_device(void)
return err;
}

+ if (thresholding_irq_en)
+ mce_threshold_vector = amd_threshold_interrupt;
+
return 0;
}
/*
diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index 61a949d84dfa..d99a8ee9e185 100644
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -344,10 +344,10 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
sanitize_restored_xstate(tsk, &env, xfeatures, fx_only);
}

+ local_bh_disable();
fpu->initialized = 1;
- preempt_disable();
fpu__restore(fpu);
- preempt_enable();
+ local_bh_enable();

return err;
} else {
diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c
index 76fa3b836598..ec6fefbfd3c0 100644
--- a/arch/x86/kernel/head32.c
+++ b/arch/x86/kernel/head32.c
@@ -37,7 +37,6 @@ asmlinkage __visible void __init i386_start_kernel(void)
cr4_init_shadow();

sanitize_boot_params(&boot_params);
- x86_verify_bootdata_version();

x86_early_init_platform_quirks();

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 7663a8eb602b..16b1cbd3a61e 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -457,8 +457,6 @@ void __init x86_64_start_reservations(char *real_mode_data)
if (!boot_params.hdr.version)
copy_bootdata(__va(real_mode_data));

- x86_verify_bootdata_version();
-
x86_early_init_platform_quirks();

switch (boot_params.hdr.hardware_subarch) {
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index b74e7bfed6ab..d494b9bfe618 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1280,23 +1280,6 @@ void __init setup_arch(char **cmdline_p)
unwind_init();
}

-/*
- * From boot protocol 2.14 onwards we expect the bootloader to set the
- * version to "0x8000 | <used version>". In case we find a version >= 2.14
- * without the 0x8000 we assume the boot loader supports 2.13 only and
- * reset the version accordingly. The 0x8000 flag is removed in any case.
- */
-void __init x86_verify_bootdata_version(void)
-{
- if (boot_params.hdr.version & VERSION_WRITTEN)
- boot_params.hdr.version &= ~VERSION_WRITTEN;
- else if (boot_params.hdr.version >= 0x020e)
- boot_params.hdr.version = 0x020d;
-
- if (boot_params.hdr.version < 0x020e)
- boot_params.hdr.acpi_rsdp_addr = 0;
-}
-
#ifdef CONFIG_X86_32

static struct resource video_ram_resource = {
diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h
index 40b0b4c1bf7b..df20f8bdbfa3 100644
--- a/include/linux/tracehook.h
+++ b/include/linux/tracehook.h
@@ -83,8 +83,8 @@ static inline int ptrace_report_syscall(struct pt_regs *regs)
* tracehook_report_syscall_entry - task is about to attempt a system call
* @regs: user register state of current task
*
- * This will be called if %TIF_SYSCALL_TRACE has been set, when the
- * current task has just entered the kernel for a system call.
+ * This will be called if %TIF_SYSCALL_TRACE or %TIF_SYSCALL_EMU have been set,
+ * when the current task has just entered the kernel for a system call.
* Full user register state is available here. Changing the values
* in @regs can affect the system call number and arguments to be tried.
* It is safe to block here, preventing the system call from beginning.