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* | | Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds2020-01-281-5/+3
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "Misc updates: - Remove last remaining calls to exception_enter/exception_exit() and simplify the entry code some more. - Remove force_iret() - Add support for "Fast Short Rep Mov", which is available starting with Ice Lake Intel CPUs - and make the x86 assembly version of memmove() use REP MOV for all sizes when FSRM is available. - Micro-optimize/simplify the 32-bit boot code a bit. - Use a more future-proof SYSRET instruction mnemonic" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Simplify calculation of output address x86/entry/64: Add instruction suffix to SYSRET x86: Remove force_iret() x86/cpufeatures: Add support for fast short REP; MOVSB x86/context-tracking: Remove exception_enter/exit() from KVM_PV_REASON_PAGE_NOT_PRESENT async page fault x86/context-tracking: Remove exception_enter/exit() from do_page_fault()
| * | | x86/boot: Simplify calculation of output addressArvind Sankar2020-01-231-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Condense the calculation of decompressed kernel start a little. Committer notes: before: ebp = ebx - (init_size - _end) after: eax = (ebx + _end) - init_size where in both ebx contains the temporary address the kernel is moved to for in-place decompression. The before and after difference in register state is %eax and %ebp but that is immaterial because the compressed image is not built with -mregparm, i.e., all arguments of the following extract_kernel() call are passed on the stack. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200107194436.2166846-1-nivedita@alum.mit.edu
* | | | efi/libstub/x86: Fix EFI server boot failureQian Cai2020-01-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | x86_64 EFI systems are unable to boot due to a typo in a recent commit: EFI config tables not found. -- System halted This was probably due to the absense of CONFIG_EFI_MIXED=y in testing. Fixes: 796eb8d26a57 ("efi/libstub/x86: Use const attribute for efi_is_64bit()") Signed-off-by: Qian Cai <cai@lca.pw> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: tglx@linutronix.de Cc: linux-efi@vger.kernel.org Link: https://lore.kernel.org/r/20200122191430.4888-1-cai@lca.pw
* | | | x86/boot/compressed: Relax sed symbol type regex for LLVM ld.lldArd Biesheuvel2020-01-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The final build stage of the x86 kernel captures some symbol addresses from the decompressor binary and copies them into zoffset.h. It uses sed with a regular expression that matches the address, symbol type and symbol name, and mangles the captured addresses and the names of symbols of interest into #define directives that are added to zoffset.h The symbol type is indicated by a single letter, which we match strictly: only letters in the set 'ABCDGRSTVW' are matched, even though the actual symbol type is relevant and therefore ignored. Commit bc7c9d620 ("efi/libstub/x86: Force 'hidden' visibility for extern declarations") made a change to the way external symbol references are classified, resulting in 'startup_32' now being emitted as a hidden symbol. This prevents the use of GOT entries to refer to this symbol via its absolute address, which recent toolchains (including Clang based ones) already avoid by default, making this change a no-op in the majority of cases. However, as it turns out, the LLVM linker classifies such hidden symbols as symbols with static linkage in fully linked ELF binaries, causing tools such as NM to output a lowercase 't' rather than an upper case 'T' for the type of such symbols. Since our sed expression only matches upper case letters for the symbol type, the line describing startup_32 is disregarded, resulting in a build error like the following arch/x86/boot/header.S:568:18: error: symbol 'ZO_startup_32' can not be undefined in a subtraction expression init_size: .long (0x00000000008fd000 - ZO_startup_32 + (((0x0000000001f6361c + ((0x0000000001f6361c >> 8) + 65536) - 0x00000000008c32e5) + 4095) & ~4095)) # kernel initialization size Given that we are only interested in the value of the symbol, let's match any character in the set 'a-zA-Z' instead. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Nathan Chancellor <natechancellor@gmail.com>
* | | | efi/libstub/x86: Fix unused-variable warningArnd Bergmann2020-01-201-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The only users of these got removed, so they also need to be removed to avoid warnings: arch/x86/boot/compressed/eboot.c: In function 'setup_efi_pci': arch/x86/boot/compressed/eboot.c:117:16: error: unused variable 'nr_pci' [-Werror=unused-variable] unsigned long nr_pci; ^~~~~~ arch/x86/boot/compressed/eboot.c: In function 'setup_uga': arch/x86/boot/compressed/eboot.c:244:16: error: unused variable 'nr_ugas' [-Werror=unused-variable] unsigned long nr_ugas; ^~~~~~~ Fixes: 2732ea0d5c0a ("efi/libstub: Use a helper to iterate over a EFI handle array") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200113172245.27925-4-ardb@kernel.org
* | | | efi/libstub/x86: Use mandatory 16-byte stack alignment in mixed modeArd Biesheuvel2020-01-201-33/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reduce the stack frame of the EFI stub's mixed mode thunk routine by 8 bytes, by moving the GDT and return addresses to EBP and EBX, which we need to preserve anyway, since their top halves will be cleared by the call into 32-bit firmware code. Doing so results in the UEFI code being entered with a 16 byte aligned stack, as mandated by the UEFI spec, fixing the last occurrence in the 64-bit kernel where we violate this requirement. Also, move the saved GDT from a global variable to an unused part of the stack frame, and touch up some other parts of the code. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200113172245.27925-3-ardb@kernel.org
* | | | efi/libstub/x86: Use const attribute for efi_is_64bit()Ard Biesheuvel2020-01-202-12/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reshuffle the x86 stub code a bit so that we can tag the efi_is_64bit() function with the 'const' attribute, which permits the compiler to optimize away any redundant calls. Since we have two different entry points for 32 and 64 bit firmware in the startup code, this also simplifies the C code since we'll enter it with the efi_is64 variable already set. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200113172245.27925-2-ardb@kernel.org
* | | | efi/x86: Allow translating 64-bit arguments for mixed mode callsArvind Sankar2020-01-101-16/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce the ability to define macros to perform argument translation for the calls that need it, and define them for the boot services that we currently use. When calling 32-bit firmware methods in mixed mode, all output parameters that are 32-bit according to the firmware, but 64-bit in the kernel (ie OUT UINTN * or OUT VOID **) must be initialized in the kernel, or the upper 32 bits may contain garbage. Define macros that zero out the upper 32 bits of the output before invoking the firmware method. When a 32-bit EFI call takes 64-bit arguments, the mixed-mode call must push the two 32-bit halves as separate arguments onto the stack. This can be achieved by splitting the argument into its two halves when calling the assembler thunk. Define a macro to do this for the free_pages boot service. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Matthew Garrett <mjg59@google.com> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20200103113953.9571-17-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/x86: Check number of arguments to variadic functionsArvind Sankar2020-01-101-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On x86 we need to thunk through assembler stubs to call the EFI services for mixed mode, and for runtime services in 64-bit mode. The assembler stubs have limits on how many arguments it handles. Introduce a few macros to check that we do not try to pass too many arguments to the stubs. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Matthew Garrett <mjg59@google.com> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20200103113953.9571-16-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub/x86: Force 'hidden' visibility for extern declarationsArd Biesheuvel2020-01-101-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit c3710de5065d ("efi/libstub/x86: Drop __efi_early() export and efi_config struct") introduced a reference from C code in eboot.c to the startup_32 symbol defined in the .S startup code. This results in a GOT based reference to startup_32, and since GOT entries carry absolute addresses, they need to be fixed up before they can be used. On modern toolchains (binutils 2.26 or later), this reference is relaxed into a R_386_GOTOFF relocation (or the analogous X86_64 one) which never uses the absolute address in the entry, and so we get away with not fixing up the GOT table before calling the EFI entry point. However, GCC 4.6 combined with a binutils of the era (2.24) will produce a true GOT indirected reference, resulting in a wrong value to be returned for the address of startup_32() if the boot code is not running at the address it was linked at. Fortunately, we can easily override this behavior, and force GCC to emit the GOTOFF relocations explicitly, by setting the visibility pragma 'hidden'. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Matthew Garrett <mjg59@google.com> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20200103113953.9571-3-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub: Fix boot argument handling in mixed mode entry codeArd Biesheuvel2020-01-101-7/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The mixed mode refactor actually broke mixed mode by failing to pass the bootparam structure to startup_32(). This went unnoticed because it apparently has a high tolerance for being passed random junk, and still boots fine in some cases. So let's fix this by populating %esi as required when entering via efi32_stub_entry, and while at it, preserve the arguments themselves instead of their address in memory (via the stack pointer) since that memory could be clobbered before we get to it. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Matthew Garrett <mjg59@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20200103113953.9571-2-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub/x86: Avoid globals to store context during mixed mode callsArd Biesheuvel2019-12-251-14/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of storing the return address in a global variable when calling a 32-bit EFI service from the 64-bit stub, avoid the indirection via efi_exit32, and take the return address from the stack. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-26-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub: Rename efi_call_early/_runtime macros to be more intuitiveArd Biesheuvel2019-12-251-42/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The macros efi_call_early and efi_call_runtime are used to call EFI boot services and runtime services, respectively. However, the naming is confusing, given that the early vs runtime distinction may suggest that these are used for calling the same set of services either early or late (== at runtime), while in reality, the sets of services they can be used with are completely disjoint, and efi_call_runtime is also only usable in 'early' code. So do a global sweep to replace all occurrences with efi_bs_call or efi_rt_call, respectively, where BS and RT match the idiom used by the UEFI spec to refer to boot time or runtime services. While at it, use 'func' as the macro parameter name for the function pointers, which is less likely to collide and cause weird build errors. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-24-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub: Drop 'table' argument from efi_table_attr() macroArd Biesheuvel2019-12-251-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | None of the definitions of the efi_table_attr() still refer to their 'table' argument so let's get rid of it entirely. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-23-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub: Drop protocol argument from efi_call_proto() macroArd Biesheuvel2019-12-251-14/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After refactoring the mixed mode support code, efi_call_proto() no longer uses its protocol argument in any of its implementation, so let's remove it altogether. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-22-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub/x86: Work around page freeing issue in mixed modeArd Biesheuvel2019-12-251-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mixed mode translates calls from the 64-bit kernel into the 32-bit firmware by wrapping them in a call to a thunking routine that pushes a 32-bit word onto the stack for each argument passed to the function, regardless of the argument type. This works surprisingly well for most services and protocols, with the exception of ones that take explicit 64-bit arguments. efi_free() invokes the FreePages() EFI boot service, which takes a efi_physical_addr_t as its address argument, and this is one of those 64-bit types. This means that the 32-bit firmware will interpret the (addr, size) pair as a single 64-bit quantity, and since it is guaranteed to have the high word set (as size > 0), it will always fail due to the fact that EFI memory allocations are always < 4 GB on 32-bit firmware. So let's fix this by giving the thunking code a little hand, and pass two values for the address, and a third one for the size. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-21-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub: Remove 'sys_table_arg' from all function prototypesArd Biesheuvel2019-12-251-22/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have a helper efi_system_table() that gives us the address of the EFI system table in memory, so there is no longer point in passing it around from each function to the next. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-20-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub: Drop sys_table_arg from printk routinesArd Biesheuvel2019-12-251-14/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As a first step towards getting rid of the need to pass around a function parameter 'sys_table_arg' pointing to the EFI system table, remove the references to it in the printing code, which is represents the majority of the use cases. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-19-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub/x86: Drop __efi_early() export and efi_config structArd Biesheuvel2019-12-253-169/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The various pointers we stash in the efi_config struct which we retrieve using __efi_early() are simply copies of the ones in the EFI system table, which we have started accessing directly in the previous patch. So drop all the __efi_early() related plumbing, as well as all the assembly code dealing with efi_config, which allows us to move the PE/COFF entry point to C code as well. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-18-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub: Unify the efi_char16_printk implementationsArd Biesheuvel2019-12-251-7/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use a single implementation for efi_char16_printk() across all architectures. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-17-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub: Get rid of 'sys_table_arg' macro parameterArd Biesheuvel2019-12-251-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The efi_call macros on ARM have a dependency on a variable 'sys_table_arg' existing in the scope of the macro instantiation. Since this variable always points to the same data structure, let's create a global getter for it and use that instead. Note that the use of a global variable with external linkage is avoided, given the problems we had in the past with early processing of the GOT tables. While at it, drop the redundant casts in the efi_table_attr and efi_call_proto macros. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-16-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub/x86: Avoid thunking for native firmware callsArd Biesheuvel2019-12-256-122/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We use special wrapper routines to invoke firmware services in the native case as well as the mixed mode case. For mixed mode, the need is obvious, but for the native cases, we can simply rely on the compiler to generate the indirect call, given that GCC now has support for the MS calling convention (and has had it for quite some time now). Note that on i386, the decompressor and the EFI stub are not built with -mregparm=3 like the rest of the i386 kernel, so we can safely allow the compiler to emit the indirect calls here as well. So drop all the wrappers and indirection, and switch to either native calls, or direct calls into the thunk routine for mixed mode. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-14-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub: Annotate firmware routines as __efiapiArd Biesheuvel2019-12-251-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Annotate all the firmware routines (boot services, runtime services and protocol methods) called in the boot context as __efiapi, and make it expand to __attribute__((ms_abi)) on 64-bit x86. This allows us to use the compiler to generate the calls into firmware that use the MS calling convention instead of the SysV one. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-13-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub: Use stricter typing for firmware function pointersArd Biesheuvel2019-12-252-7/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We will soon remove another level of pointer casting, so let's make sure all type handling involving firmware calls at boot time is correct. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-12-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub: Drop explicit 32/64-bit protocol definitionsArd Biesheuvel2019-12-251-12/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we have incorporated the mixed mode protocol definitions into the native ones using unions, we no longer need the separate 32/64 bit struct definitions, with the exception of the EFI system table definition and the boot services, runtime services and configuration table definitions. So drop the unused ones. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-11-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub: Distinguish between native/mixed not 32/64 bitArd Biesheuvel2019-12-251-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, we support mixed mode by casting all boot time firmware calls to 64-bit explicitly on native 64-bit systems, and to 32-bit on 32-bit systems or 64-bit systems running with 32-bit firmware. Due to this explicit awareness of the bitness in the code, we do a lot of casting even on generic code that is shared with other architectures, where mixed mode does not even exist. This casting leads to loss of coverage of type checking by the compiler, which we should try to avoid. So instead of distinguishing between 32-bit vs 64-bit, distinguish between native vs mixed, and limit all the nasty casting and pointer mangling to the code that actually deals with mixed mode. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-10-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub: Extend native protocol definitions with mixed_mode aliasesArd Biesheuvel2019-12-251-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation of moving to a native vs. mixed mode split rather than a 32 vs. 64 bit split when it comes to invoking EFI firmware services, update all the native protocol definitions and redefine them as unions containing an anonymous struct for the native view and a struct called 'mixed_mode' describing the 32-bit view of the protocol when called from 64-bit code. While at it, flesh out some PCI I/O member definitions that we will be needing shortly. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-9-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | efi/libstub: Use a helper to iterate over a EFI handle arrayArd Biesheuvel2019-12-251-9/+5
| |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Iterating over a EFI handle array is a bit finicky, since we have to take mixed mode into account, where handles are only 32-bit while the native efi_handle_t type is 64-bit. So introduce a helper, and replace the various occurrences of this pattern. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-8-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | x86/efistub: Disable paging at mixed mode entryArd Biesheuvel2019-12-251-0/+5
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The EFI mixed mode entry code goes through the ordinary startup_32() routine before jumping into the kernel's EFI boot code in 64-bit mode. The 32-bit startup code must be entered with paging disabled, but this is not documented as a requirement for the EFI handover protocol, and so we should disable paging explicitly when entering the kernel from 32-bit EFI firmware. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: <stable@vger.kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224132909.102540-4-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* / x86/boot: kbuild: allow readelf executable to be specifiedDmitry Golovin2019-12-141-1/+1
|/ | | | | | | | | | | | | | | | | Introduce a new READELF variable to top-level Makefile, so the name of readelf binary can be specified. Before this change the name of the binary was hardcoded to "$(CROSS_COMPILE)readelf" which might not be present for every toolchain. This allows to build with LLVM Object Reader by using make parameter READELF=llvm-readelf. Link: https://github.com/ClangBuiltLinux/linux/issues/771 Signed-off-by: Dmitry Golovin <dima@golovin.in> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* Merge tag 'acpi-5.5-rc1' of ↵Linus Torvalds2019-11-262-8/+44
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI updates from Rafael Wysocki: "These update the ACPICA code in the kernel to upstream revision 20191018, add support for EFI specific purpose memory, update the ACPI EC driver to make it work on systems with hardware-reduced ACPI, improve ACPI-based device enumeration for some platforms, rework the lid blacklist handling in the button driver and add more lid quirks to it, unify ACPI _HID/_UID matching, fix assorted issues and clean up the code and documentation. Specifics: - Update the ACPICA code in the kernel to upstream revision 20191018 including: * Fixes for Clang warnings (Bob Moore) * Fix for possible overflow in get_tick_count() (Bob Moore) * Introduction of acpi_unload_table() (Bob Moore) * Debugger and utilities updates (Erik Schmauss) * Fix for unloading tables loaded via configfs (Nikolaus Voss) - Add support for EFI specific purpose memory to optionally allow either application-exclusive or core-kernel-mm managed access to differentiated memory (Dan Williams) - Fix and clean up processing of the HMAT table (Brice Goglin, Qian Cai, Tao Xu) - Update the ACPI EC driver to make it work on systems with hardware-reduced ACPI (Daniel Drake) - Always build in support for the Generic Event Device (GED) to allow one kernel binary to work both on systems with full hardware ACPI and hardware-reduced ACPI (Arjan van de Ven) - Fix the table unload mechanism to unregister platform devices created when the given table was loaded (Andy Shevchenko) - Rework the lid blacklist handling in the button driver and add more lid quirks to it (Hans de Goede) - Improve ACPI-based device enumeration for some platforms based on Intel BayTrail SoCs (Hans de Goede) - Add an OpRegion driver for the Cherry Trail Crystal Cove PMIC and prevent handlers from being registered for unhandled PMIC OpRegions (Hans de Goede) - Unify ACPI _HID/_UID matching (Andy Shevchenko) - Clean up documentation and comments (Cao jin, James Pack, Kacper Piwiński)" * tag 'acpi-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (52 commits) ACPI: OSI: Shoot duplicate word ACPI: HMAT: use %u instead of %d to print u32 values ACPI: NUMA: HMAT: fix a section mismatch ACPI: HMAT: don't mix pxm and nid when setting memory target processor_pxm ACPI: NUMA: HMAT: Register "soft reserved" memory as an "hmem" device ACPI: NUMA: HMAT: Register HMAT at device_initcall level device-dax: Add a driver for "hmem" devices dax: Fix alloc_dax_region() compile warning lib: Uplevel the pmem "region" ida to a global allocator x86/efi: Add efi_fake_mem support for EFI_MEMORY_SP arm/efi: EFI soft reservation to memblock x86/efi: EFI soft reservation to E820 enumeration efi: Common enable/disable infrastructure for EFI soft reservation x86/efi: Push EFI_MEMMAP check into leaf routines efi: Enumerate EFI_MEMORY_SP ACPI: NUMA: Establish a new drivers/acpi/numa/ directory ACPICA: Update version to 20191018 ACPICA: debugger: remove leading whitespaces when converting a string to a buffer ACPICA: acpiexec: initialize all simple types and field units from user input ACPICA: debugger: add field unit support for acpi_db_get_next_token ...
| * x86/efi: Add efi_fake_mem support for EFI_MEMORY_SPDan Williams2019-11-071-7/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Given that EFI_MEMORY_SP is platform BIOS policy decision for marking memory ranges as "reserved for a specific purpose" there will inevitably be scenarios where the BIOS omits the attribute in situations where it is desired. Unlike other attributes if the OS wants to reserve this memory from the kernel the reservation needs to happen early in init. So early, in fact, that it needs to happen before e820__memblock_setup() which is a pre-requisite for efi_fake_memmap() that wants to allocate memory for the updated table. Introduce an x86 specific efi_fake_memmap_early() that can search for attempts to set EFI_MEMORY_SP via efi_fake_mem and update the e820 table accordingly. The KASLR code that scans the command line looking for user-directed memory reservations also needs to be updated to consider "efi_fake_mem=nn@ss:0x40000" requests. Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * x86/efi: EFI soft reservation to E820 enumerationDan Williams2019-11-072-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | UEFI 2.8 defines an EFI_MEMORY_SP attribute bit to augment the interpretation of the EFI Memory Types as "reserved for a specific purpose". The proposed Linux behavior for specific purpose memory is that it is reserved for direct-access (device-dax) by default and not available for any kernel usage, not even as an OOM fallback. Later, through udev scripts or another init mechanism, these device-dax claimed ranges can be reconfigured and hot-added to the available System-RAM with a unique node identifier. This device-dax management scheme implements "soft" in the "soft reserved" designation by allowing some or all of the reservation to be recovered as typical memory. This policy can be disabled at compile-time with CONFIG_EFI_SOFT_RESERVE=n, or runtime with efi=nosoftreserve. This patch introduces 2 new concepts at once given the entanglement between early boot enumeration relative to memory that can optionally be reserved from the kernel page allocator by default. The new concepts are: - E820_TYPE_SOFT_RESERVED: Upon detecting the EFI_MEMORY_SP attribute on EFI_CONVENTIONAL memory, update the E820 map with this new type. Only perform this classification if the CONFIG_EFI_SOFT_RESERVE=y policy is enabled, otherwise treat it as typical ram. - IORES_DESC_SOFT_RESERVED: Add a new I/O resource descriptor for a device driver to search iomem resources for application specific memory. Teach the iomem code to identify such ranges as "Soft Reserved". Note that the comment for do_add_efi_memmap() needed refreshing since it seemed to imply that the efi map might overflow the e820 table, but that is not an issue as of commit 7b6e4ba3cb1f "x86/boot/e820: Clean up the E820_X_MAX definition" that removed the 128 entry limit for e820__range_add(). A follow-on change integrates parsing of the ACPI HMAT to identify the node and sub-range boundaries of EFI_MEMORY_SP designated memory. For now, just identify and reserve memory of this type. Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reported-by: kbuild test robot <lkp@intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | Merge branch 'efi-core-for-linus' of ↵Linus Torvalds2019-11-261-0/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI updates from Ingo Molnar: "The main changes in this cycle were: - Wire up the EFI RNG code for x86. This enables an additional source of entropy during early boot. - Enable the TPM event log code on ARM platforms. - Update Ard's email address" * 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi: libstub/tpm: enable tpm eventlog function for ARM platforms x86: efi/random: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG table efi/random: use arch-independent efi_call_proto() MAINTAINERS: update Ard's email address to @kernel.org
| * | x86: efi/random: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG tableDominik Brodowski2019-11-071-0/+3
| |/ | | | | | | | | | | | | | | | | | | | | | | | | Invoke the EFI_RNG_PROTOCOL protocol in the context of the x86 EFI stub, same as is done on arm/arm64 since commit 568bc4e87033 ("efi/arm*/libstub: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG table"). Within the stub, a Linux-specific RNG seed UEFI config table will be seeded. The EFI routines in the core kernel will pick that up later, yet still early during boot, to seed the kernel entropy pool. If CONFIG_RANDOM_TRUST_BOOTLOADER, entropy is credited for this seed. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
* | Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds2019-11-269-73/+81
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "The main changes in this cycle were: - Cross-arch changes to move the linker sections for NOTES and EXCEPTION_TABLE into the RO_DATA area, where they belong on most architectures. (Kees Cook) - Switch the x86 linker fill byte from x90 (NOP) to 0xcc (INT3), to trap jumps into the middle of those padding areas instead of sliding execution. (Kees Cook) - A thorough cleanup of symbol definitions within x86 assembler code. The rather randomly named macros got streamlined around a (hopefully) straightforward naming scheme: SYM_START(name, linkage, align...) SYM_END(name, sym_type) SYM_FUNC_START(name) SYM_FUNC_END(name) SYM_CODE_START(name) SYM_CODE_END(name) SYM_DATA_START(name) SYM_DATA_END(name) etc - with about three times of these basic primitives with some label, local symbol or attribute variant, expressed via postfixes. No change in functionality intended. (Jiri Slaby) - Misc other changes, cleanups and smaller fixes" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (67 commits) x86/entry/64: Remove pointless jump in paranoid_exit x86/entry/32: Remove unused resume_userspace label x86/build/vdso: Remove meaningless CFLAGS_REMOVE_*.o m68k: Convert missed RODATA to RO_DATA x86/vmlinux: Use INT3 instead of NOP for linker fill bytes x86/mm: Report actual image regions in /proc/iomem x86/mm: Report which part of kernel image is freed x86/mm: Remove redundant address-of operators on addresses xtensa: Move EXCEPTION_TABLE to RO_DATA segment powerpc: Move EXCEPTION_TABLE to RO_DATA segment parisc: Move EXCEPTION_TABLE to RO_DATA segment microblaze: Move EXCEPTION_TABLE to RO_DATA segment ia64: Move EXCEPTION_TABLE to RO_DATA segment h8300: Move EXCEPTION_TABLE to RO_DATA segment c6x: Move EXCEPTION_TABLE to RO_DATA segment arm64: Move EXCEPTION_TABLE to RO_DATA segment alpha: Move EXCEPTION_TABLE to RO_DATA segment x86/vmlinux: Move EXCEPTION_TABLE to RO_DATA segment x86/vmlinux: Actually use _etext for the end of the text segment vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA ...
| * \ Merge branch 'x86/build' into x86/asm, to pick up completed topic branchIngo Molnar2019-11-252-0/+2
| |\ \ | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | arch/x86/boot: Use prefix map to avoid embedded pathsBruce Ashfield2019-10-012-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It was observed that the kernel embeds the absolute build path in the x86 boot image when the __FILE__ macro is expanded. > From https://bugzilla.yoctoproject.org/show_bug.cgi?id=13458: If you turn on the buildpaths QA test, or try a reproducible build, you discover that the kernel image contains build paths. $ strings bzImage-5.0.19-yocto-standard |grep tmp/ out of pgt_buf in /data/poky-tmp/reproducible/tmp/work-shared/qemux86-64/kernel-source/arch/x86/boot/compressed/kaslr_64.c!? But what's this in the top-level Makefile: $ git grep prefix-map Makefile:KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=) So the __FILE__ shouldn't be using the full path. However arch/x86/boot/compressed/Makefile has this: KBUILD_CFLAGS := -m$(BITS) -O2 So that clears KBUILD_FLAGS, removing the -fmacro-prefix-map option. Use -fmacro-prefix-map to have relative paths in the boot image too. [ bp: Massage commit message and put the KBUILD_CFLAGS addition in ..boot/Makefile after the KBUILD_AFLAGS assignment because gas doesn't support -fmacro-prefix-map. ] Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com> Signed-off-by: Ross Burton <ross.burton@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: George Rimar <grimar@accesssoftek.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190926093226.8568-1-ross.burton@intel.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=204333
| * | | x86/asm/32: Change all ENTRY+ENDPROC to SYM_FUNC_*Jiri Slaby2019-10-182-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These are all functions which are invoked from elsewhere, so annotate them as global using the new SYM_FUNC_START and their ENDPROC's by SYM_FUNC_END. Now, ENTRY/ENDPROC can be forced to be undefined on X86, so do so. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Allison Randal <allison@lohutok.net> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Andy Shevchenko <andy@infradead.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Bill Metzenthen <billm@melbpc.org.au> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Darren Hart <dvhart@infradead.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-arch@vger.kernel.org Cc: linux-crypto@vger.kernel.org Cc: linux-efi <linux-efi@vger.kernel.org> Cc: linux-efi@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Pavel Machek <pavel@ucw.cz> Cc: platform-driver-x86@vger.kernel.org Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20191011115108.12392-28-jslaby@suse.cz
| * | | x86/asm: Change all ENTRY+ENDPROC to SYM_FUNC_*Jiri Slaby2019-10-183-14/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These are all functions which are invoked from elsewhere, so annotate them as global using the new SYM_FUNC_START and their ENDPROC's by SYM_FUNC_END. Make sure ENTRY/ENDPROC is not defined on X86_64, given these were the last users. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [hibernate] Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> [xen bits] Acked-by: Herbert Xu <herbert@gondor.apana.org.au> [crypto] Cc: Allison Randal <allison@lohutok.net> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Andy Shevchenko <andy@infradead.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Armijn Hemel <armijn@tjaldur.nl> Cc: Cao jin <caoj.fnst@cn.fujitsu.com> Cc: Darren Hart <dvhart@infradead.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Enrico Weigelt <info@metux.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jim Mattson <jmattson@google.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: kvm ML <kvm@vger.kernel.org> Cc: Len Brown <len.brown@intel.com> Cc: linux-arch@vger.kernel.org Cc: linux-crypto@vger.kernel.org Cc: linux-efi <linux-efi@vger.kernel.org> Cc: linux-efi@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: platform-driver-x86@vger.kernel.org Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wanpeng Li <wanpengli@tencent.com> Cc: Wei Huang <wei@redhat.com> Cc: x86-ml <x86@kernel.org> Cc: xen-devel@lists.xenproject.org Cc: Xiaoyao Li <xiaoyao.li@linux.intel.com> Link: https://lkml.kernel.org/r/20191011115108.12392-25-jslaby@suse.cz
| * | | x86/asm/64: Add ENDs to some functions and relabel with SYM_CODE_*Jiri Slaby2019-10-181-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All these are functions which are invoked from elsewhere but they are not typical C functions. So annotate them using the new SYM_CODE_START. All these were not balanced with any END, so mark their ends by SYM_CODE_END appropriately too. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> [xen bits] Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [power mgmt] Cc: Andy Shevchenko <andy@infradead.org> Cc: Cao jin <caoj.fnst@cn.fujitsu.com> Cc: Darren Hart <dvhart@infradead.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: linux-arch@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: Pavel Machek <pavel@ucw.cz> Cc: Pingfan Liu <kernelfans@gmail.com> Cc: platform-driver-x86@vger.kernel.org Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Huang <wei@redhat.com> Cc: x86-ml <x86@kernel.org> Cc: xen-devel@lists.xenproject.org Cc: Xiaoyao Li <xiaoyao.li@linux.intel.com> Link: https://lkml.kernel.org/r/20191011115108.12392-23-jslaby@suse.cz
| * | | x86/asm: Make some functions localJiri Slaby2019-10-181-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are a couple of assembly functions which are invoked only locally in the file they are defined. In C, they are marked "static". In assembly, annotate them using SYM_{FUNC,CODE}_START_LOCAL (and switch their ENDPROC to SYM_{FUNC,CODE}_END too). Whether FUNC or CODE is used, depends on whether ENDPROC or END was used for a particular function before. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Andy Shevchenko <andy@infradead.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Darren Hart <dvhart@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: linux-arch@vger.kernel.org Cc: linux-efi <linux-efi@vger.kernel.org> Cc: linux-efi@vger.kernel.org Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: platform-driver-x86@vger.kernel.org Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Cc: xen-devel@lists.xenproject.org Link: https://lkml.kernel.org/r/20191011115108.12392-21-jslaby@suse.cz
| * | | x86/asm: Do not annotate functions with GLOBALJiri Slaby2019-10-182-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GLOBAL is an x86's custom macro and is going to die very soon. It was meant for global symbols, but here, it was used for functions. Instead, use the new macros SYM_FUNC_START* and SYM_CODE_START* (depending on the type of the function) which are dedicated to global functions. And since they both require a closing by SYM_*_END, do that here too. startup_64, which does not use GLOBAL but uses .globl explicitly, is converted too. "No alignments" are preserved. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Allison Randal <allison@lohutok.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Cao jin <caoj.fnst@cn.fujitsu.com> Cc: Enrico Weigelt <info@metux.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-arch@vger.kernel.org Cc: Maran Wilson <maran.wilson@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20191011115108.12392-17-jslaby@suse.cz
| * | | x86/boot: Annotate data appropriatelyJiri Slaby2019-10-183-28/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the new SYM_DATA, SYM_DATA_START, and SYM_DATA_END* macros for data, so that the data in the object file look sane: Value Size Type Bind Vis Ndx Name 0000 10 OBJECT GLOBAL DEFAULT 3 efi32_boot_gdt 000a 10 OBJECT LOCAL DEFAULT 3 save_gdt 0014 8 OBJECT LOCAL DEFAULT 3 func_rt_ptr 001c 48 OBJECT GLOBAL DEFAULT 3 efi_gdt64 004c 0 OBJECT LOCAL DEFAULT 3 efi_gdt64_end 0000 48 OBJECT LOCAL DEFAULT 3 gdt 0030 0 OBJECT LOCAL DEFAULT 3 gdt_end 0030 8 OBJECT LOCAL DEFAULT 3 efi_config 0038 49 OBJECT GLOBAL DEFAULT 3 efi32_config 0069 49 OBJECT GLOBAL DEFAULT 3 efi64_config All have correct size and type now. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Allison Randal <allison@lohutok.net> Cc: Cao jin <caoj.fnst@cn.fujitsu.com> Cc: Enrico Weigelt <info@metux.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: linux-arch@vger.kernel.org Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Huang <wei@redhat.com> Cc: x86-ml <x86@kernel.org> Cc: Xiaoyao Li <xiaoyao.li@linux.intel.com> Link: https://lkml.kernel.org/r/20191011115108.12392-13-jslaby@suse.cz
| * | | x86/boot: Annotate local functionsJiri Slaby2019-10-183-6/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | .Lrelocated, .Lpaging_enabled, .Lno_longmode, and .Lin_pm32 are self-standing local functions, annotate them as such and preserve "no alignment". The annotations do not generate anything yet. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Cao jin <caoj.fnst@cn.fujitsu.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: linux-arch@vger.kernel.org Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Huang <wei@redhat.com> Cc: x86-ml <x86@kernel.org> Cc: Xiaoyao Li <xiaoyao.li@linux.intel.com> Link: https://lkml.kernel.org/r/20191011115108.12392-8-jslaby@suse.cz
| * | | x86/asm: Make more symbols localJiri Slaby2019-10-111-3/+3
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During the assembly cleanup patchset review, I found more symbols which are used only locally. So make them really local by prepending ".L" to them. Namely: - wakeup_idt is used only in realmode/rm/wakeup_asm.S. - in_pm32 is used only in boot/pmjump.S. - retint_user is used only in entry/entry_64.S, perhaps since commit 2ec67971facc ("x86/entry/64/compat: Remove most of the fast system call machinery"), where entry_64_compat's caller was removed. Drop GLOBAL from all of them too. I do not see more candidates in the series. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@alien8.de Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/20191011092213.31470-1-jslaby@suse.cz Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | Merge branch 'x86-boot-for-linus' of ↵Linus Torvalds2019-11-266-4/+44
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot updates from Ingo Molnar: "The main changes were: - Extend the boot protocol to allow future extensions without hitting the setup_header size limit. - Add quirk to devicetree systems to disable the RTC unless it's listed as a supported device. - Fix ld.lld linker pedantry" * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Introduce setup_indirect x86/boot: Introduce kernel_info.setup_type_max x86/boot: Introduce kernel_info x86/init: Allow DT configured systems to disable RTC at boot time x86/realmode: Explicitly set entry point via ENTRY in linker script
| * | x86/boot: Introduce setup_indirectDaniel Kiper2019-11-123-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The setup_data is a bit awkward to use for extremely large data objects, both because the setup_data header has to be adjacent to the data object and because it has a 32-bit length field. However, it is important that intermediate stages of the boot process have a way to identify which chunks of memory are occupied by kernel data. Thus introduce an uniform way to specify such indirect data as setup_indirect struct and SETUP_INDIRECT type. And finally bump setup_header version in arch/x86/boot/header.S. Suggested-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Ross Philipson <ross.philipson@oracle.com> Reviewed-by: H. Peter Anvin (Intel) <hpa@zytor.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: ard.biesheuvel@linaro.org Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: dave.hansen@linux.intel.com Cc: eric.snowberg@oracle.com Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Juergen Gross <jgross@suse.com> Cc: kanth.ghatraju@oracle.com Cc: linux-doc@vger.kernel.org Cc: linux-efi <linux-efi@vger.kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: rdunlap@infradead.org Cc: ross.philipson@oracle.com Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Cc: xen-devel@lists.xenproject.org Link: https://lkml.kernel.org/r/20191112134640.16035-4-daniel.kiper@oracle.com
| * | x86/boot: Introduce kernel_info.setup_type_maxDaniel Kiper2019-11-121-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This field contains maximal allowed type for setup_data. Do not bump setup_header version in arch/x86/boot/header.S because it will be followed by additional changes coming into the Linux/x86 boot protocol. Suggested-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Ross Philipson <ross.philipson@oracle.com> Reviewed-by: H. Peter Anvin (Intel) <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: ard.biesheuvel@linaro.org Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: dave.hansen@linux.intel.com Cc: eric.snowberg@oracle.com Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Juergen Gross <jgross@suse.com> Cc: kanth.ghatraju@oracle.com Cc: linux-doc@vger.kernel.org Cc: linux-efi <linux-efi@vger.kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: rdunlap@infradead.org Cc: ross.philipson@oracle.com Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Cc: xen-devel@lists.xenproject.org Link: https://lkml.kernel.org/r/20191112134640.16035-3-daniel.kiper@oracle.com
| * | x86/boot: Introduce kernel_infoDaniel Kiper2019-11-125-3/+26
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The relationships between the headers are analogous to the various data sections: setup_header = .data boot_params/setup_data = .bss What is missing from the above list? That's right: kernel_info = .rodata We have been (ab)using .data for things that could go into .rodata or .bss for a long time, for lack of alternatives and -- especially early on -- inertia. Also, the BIOS stub is responsible for creating boot_params, so it isn't available to a BIOS-based loader (setup_data is, though). setup_header is permanently limited to 144 bytes due to the reach of the 2-byte jump field, which doubles as a length field for the structure, combined with the size of the "hole" in struct boot_params that a protected-mode loader or the BIOS stub has to copy it into. It is currently 119 bytes long, which leaves us with 25 very precious bytes. This isn't something that can be fixed without revising the boot protocol entirely, breaking backwards compatibility. boot_params proper is limited to 4096 bytes, but can be arbitrarily extended by adding setup_data entries. It cannot be used to communicate properties of the kernel image, because it is .bss and has no image-provided content. kernel_info solves this by providing an extensible place for information about the kernel image. It is readonly, because the kernel cannot rely on a bootloader copying its contents anywhere, but that is OK; if it becomes necessary it can still contain data items that an enabled bootloader would be expected to copy into a setup_data chunk. Do not bump setup_header version in arch/x86/boot/header.S because it will be followed by additional changes coming into the Linux/x86 boot protocol. Suggested-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Ross Philipson <ross.philipson@oracle.com> Reviewed-by: H. Peter Anvin (Intel) <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: ard.biesheuvel@linaro.org Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: dave.hansen@linux.intel.com Cc: eric.snowberg@oracle.com Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Juergen Gross <jgross@suse.com> Cc: kanth.ghatraju@oracle.com Cc: linux-doc@vger.kernel.org Cc: linux-efi <linux-efi@vger.kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: rdunlap@infradead.org Cc: ross.philipson@oracle.com Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Cc: xen-devel@lists.xenproject.org Link: https://lkml.kernel.org/r/20191112134640.16035-2-daniel.kiper@oracle.com