From d19f9130b814d33c03118493c17454f7d90075d1 Mon Sep 17 00:00:00 2001 From: Elvira Khabirova Date: Sat, 10 Nov 2018 04:22:09 +0100 Subject: x86/ptrace: Fix documentation for tracehook_report_syscall_entry() tracehook_report_syscall_entry() is called not only if %TIF_SYSCALL_TRACE is set, but also if %TIF_SYSCALL_EMU is set, as appears from x86's entry code. Signed-off-by: Elvira Khabirova Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: ldv@altlinux.org Cc: oleg@redhat.com Cc: rostedt@goodmis.org Link: http://lkml.kernel.org/r/20181110042209.26333972@akathisia Signed-off-by: Ingo Molnar --- include/linux/tracehook.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) 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. -- cgit v1.2.3 From 3841840449817ba6cf3e636008bc4e1061a03388 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Tue, 20 Nov 2018 08:25:28 +0100 Subject: x86/boot: Mostly revert commit ae7e1238e68f2a ("Add ACPI RSDP address to setup_header") Peter Anvin pointed out that commit: ae7e1238e68f2a ("x86/boot: Add ACPI RSDP address to setup_header") should be reverted as setup_header should only contain items set by the legacy BIOS. So revert said commit. Instead of fully reverting the dependent commit of: e7b66d16fe4172 ("x86/acpi, x86/boot: Take RSDP address for boot params if available") just remove the setup_header reference in order to replace it by a boot_params in a followup patch. Suggested-by: "H. Peter Anvin" Signed-off-by: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: boris.ostrovsky@oracle.com Cc: bp@alien8.de Cc: daniel.kiper@oracle.com Cc: sstabellini@kernel.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/20181120072529.5489-2-jgross@suse.com Signed-off-by: Ingo Molnar --- Documentation/x86/boot.txt | 32 +------------------------------- arch/x86/boot/header.S | 6 +----- arch/x86/include/asm/x86_init.h | 2 -- arch/x86/include/uapi/asm/bootparam.h | 4 ---- arch/x86/kernel/acpi/boot.c | 2 +- arch/x86/kernel/head32.c | 1 - arch/x86/kernel/head64.c | 2 -- arch/x86/kernel/setup.c | 17 ----------------- 8 files changed, 3 insertions(+), 63 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/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..a06cbf019744 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 { diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index 92c76bf97ad8..fb3b1f3a5aba 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 0; } 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 | ". 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 = { -- cgit v1.2.3 From e6e094e053af75cbc164e950814d3d084fb1e698 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Tue, 20 Nov 2018 08:25:29 +0100 Subject: x86/acpi, x86/boot: Take RSDP address from boot params if available In case the RSDP address in struct boot_params is specified don't try to find the table by searching, but take the address directly as set by the boot loader. Suggested-by: "H. Peter Anvin" Signed-off-by: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: boris.ostrovsky@oracle.com Cc: bp@alien8.de Cc: daniel.kiper@oracle.com Cc: sstabellini@kernel.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/20181120072529.5489-3-jgross@suse.com Signed-off-by: Ingo Molnar --- arch/x86/include/uapi/asm/bootparam.h | 3 ++- arch/x86/kernel/acpi/boot.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h index a06cbf019744..60733f137e9a 100644 --- a/arch/x86/include/uapi/asm/bootparam.h +++ b/arch/x86/include/uapi/asm/bootparam.h @@ -155,7 +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 fb3b1f3a5aba..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 0; + return boot_params.acpi_rsdp_addr; } -- cgit v1.2.3 From 68239654acafe6aad5a3c1dc7237e60accfebc03 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Tue, 20 Nov 2018 11:26:35 +0100 Subject: x86/fpu: Disable bottom halves while loading FPU registers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The sequence fpu->initialized = 1; /* step A */ preempt_disable(); /* step B */ fpu__restore(fpu); preempt_enable(); in __fpu__restore_sig() is racy in regard to a context switch. For 32bit frames, __fpu__restore_sig() prepares the FPU state within fpu->state. To ensure that a context switch (switch_fpu_prepare() in particular) does not modify fpu->state it uses fpu__drop() which sets fpu->initialized to 0. After fpu->initialized is cleared, the CPU's FPU state is not saved to fpu->state during a context switch. The new state is loaded via fpu__restore(). It gets loaded into fpu->state from userland and ensured it is sane. fpu->initialized is then set to 1 in order to avoid fpu__initialize() doing anything (overwrite the new state) which is part of fpu__restore(). A context switch between step A and B above would save CPU's current FPU registers to fpu->state and overwrite the newly prepared state. This looks like a tiny race window but the Kernel Test Robot reported this back in 2016 while we had lazy FPU support. Borislav Petkov made the link between that report and another patch that has been posted. Since the removal of the lazy FPU support, this race goes unnoticed because the warning has been removed. Disable bottom halves around the restore sequence to avoid the race. BH need to be disabled because BH is allowed to run (even with preemption disabled) and might invoke kernel_fpu_begin() by doing IPsec. [ bp: massage commit message a bit. ] Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Borislav Petkov Acked-by: Ingo Molnar Acked-by: Thomas Gleixner Cc: Andy Lutomirski Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: "Jason A. Donenfeld" Cc: kvm ML Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Rik van Riel Cc: stable@vger.kernel.org Cc: x86-ml Link: http://lkml.kernel.org/r/20181120102635.ddv3fvavxajjlfqk@linutronix.de Link: https://lkml.kernel.org/r/20160226074940.GA28911@pd.tnic --- arch/x86/kernel/fpu/signal.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) 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 { -- cgit v1.2.3 From ac26d1f74cfc19c8dc9d533b5f20e99dbee3d9bd Mon Sep 17 00:00:00 2001 From: Jann Horn Date: Tue, 27 Nov 2018 14:32:00 +0100 Subject: x86/fpu: Use the correct exception table macro in the XSTATE_OP wrapper Commit 75045f77f7a7 ("x86/extable: Introduce _ASM_EXTABLE_UA for uaccess fixups") incorrectly replaced the fixup entry for XSTATE_OP with a user-#PF-only fixup. XRSTOR can also raise #GP if the xstate content is invalid, and _ASM_EXTABLE_UA doesn't expect that. Change this fixup back to _ASM_EXTABLE so that #GP gets fixed up. Fixes: 75045f77f7a7 ("x86/extable: Introduce _ASM_EXTABLE_UA for uaccess fixups") Reported-by: Sebastian Andrzej Siewior Signed-off-by: Jann Horn Signed-off-by: Borislav Petkov Acked-by: Sebastian Andrzej Siewior Tested-by: Sebastian Andrzej Siewior Cc: "H. Peter Anvin" Cc: "Naveen N. Rao" Cc: Andy Lutomirski Cc: Ingo Molnar Cc: Thomas Gleixner Cc: kernel-hardening@lists.openwall.com Cc: x86-ml Link: https://lkml.kernel.org/r/20181126165957.xhsyu2dhyy45mrjo@linutronix.de Link: https://lkml.kernel.org/r/20181127133200.38322-1-jannh@google.com --- arch/x86/include/asm/fpu/internal.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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") -- cgit v1.2.3 From 60c8144afc287ef09ce8c1230c6aa972659ba1bb Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Tue, 27 Nov 2018 14:41:37 +0100 Subject: x86/MCE/AMD: Fix the thresholding machinery initialization order MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently, the code sets up the thresholding interrupt vector and only then goes about initializing the thresholding banks. Which is wrong, because an early thresholding interrupt would cause a NULL pointer dereference when accessing those banks and prevent the machine from booting. Therefore, set the thresholding interrupt vector only *after* having initialized the banks successfully. Fixes: 18807ddb7f88 ("x86/mce/AMD: Reset Threshold Limit after logging error") Reported-by: Rafał Miłecki Reported-by: John Clemens Signed-off-by: Borislav Petkov Tested-by: Rafał Miłecki Tested-by: John Clemens Cc: Aravind Gopalakrishnan Cc: linux-edac@vger.kernel.org Cc: stable@vger.kernel.org Cc: Tony Luck Cc: x86@kernel.org Cc: Yazen Ghannam Link: https://lkml.kernel.org/r/20181127101700.2964-1-zajec5@gmail.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=201291 --- arch/x86/kernel/cpu/mcheck/mce_amd.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) 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; } /* -- cgit v1.2.3