linux-dev/arch/x86/platform/pvh, branch master

x86,xen,objtool: Add UNWIND hint

2022-04-19T19:58:47Z

SYM_CODE_START*() doesn't get auto-validated and needs an UNWIND hint to get checked, add one. vmlinux.o: warning: objtool: pvh_start_xen()+0x0: unreachable Reported-by: Thomas Gleixner Reported-by: Rick Edgecombe Signed-off-by: Peter Zijlstra (Intel) Acked-by: Josh Poimboeuf Link: https://lore.kernel.org/r/20220408094718.321246297@infradead.org

x86/PVH: adjust function/data placement

2021-10-05T06:36:17Z

Two of the variables can live in .init.data, allowing the open-coded placing in .data to go away. Another "variable" is used to communicate a size value only to very early assembly code, which hence can be both const and live in .init.*. Additionally two functions were lacking __init annotations. Signed-off-by: Jan Beulich Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/3b0bb22e-43f4-e459-c5cb-169f996b5669@suse.com Signed-off-by: Juergen Gross

Merge tag 'x86_core_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2021-04-28T00:45:09Z

Pull x86 updates from Borislav Petkov: - Turn the stack canary into a normal __percpu variable on 32-bit which gets rid of the LAZY_GS stuff and a lot of code. - Add an insn_decode() API which all users of the instruction decoder should preferrably use. Its goal is to keep the details of the instruction decoder away from its users and simplify and streamline how one decodes insns in the kernel. Convert its users to it. - kprobes improvements and fixes - Set the maximum DIE per package variable on Hygon - Rip out the dynamic NOP selection and simplify all the machinery around selecting NOPs. Use the simplified NOPs in objtool now too. - Add Xeon Sapphire Rapids to list of CPUs that support PPIN - Simplify the retpolines by folding the entire thing into an alternative now that objtool can handle alternatives with stack ops. Then, have objtool rewrite the call to the retpoline with the alternative which then will get patched at boot time. - Document Intel uarch per models in intel-family.h - Make Sub-NUMA Clustering topology the default and Cluster-on-Die the exception on Intel. * tag 'x86_core_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits) x86, sched: Treat Intel SNC topology as default, COD as exception x86/cpu: Comment Skylake server stepping too x86/cpu: Resort and comment Intel models objtool/x86: Rewrite retpoline thunk calls objtool: Skip magical retpoline .altinstr_replacement objtool: Cache instruction relocs objtool: Keep track of retpoline call sites objtool: Add elf_create_undef_symbol() objtool: Extract elf_symbol_add() objtool: Extract elf_strtab_concat() objtool: Create reloc sections implicitly objtool: Add elf_create_reloc() helper objtool: Rework the elf_rebuild_reloc_section() logic objtool: Fix static_call list generation objtool: Handle per arch retpoline naming objtool: Correctly handle retpoline thunk calls x86/retpoline: Simplify retpolines x86/alternatives: Optimize optimize_nops() x86: Add insn_decode_kernel() x86/kprobes: Move 'inline' to the beginning of the kprobe_is_ss() declaration ...

x86: Remove unusual Unicode characters from comments

2021-03-21T22:50:07Z

We've accumulated a few unusual Unicode characters in arch/x86/ over the years, substitute them with their proper ASCII equivalents. A few of them were a whitespace equivalent: ' ' - the use was harmless. Signed-off-by: Ingo Molnar Cc: Borislav Petkov Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: linux-kernel@vger.kernel.org

x86/stackprotector/32: Make the canary into a regular percpu variable

2021-03-08T12:19:05Z

On 32-bit kernels, the stackprotector canary is quite nasty -- it is stored at %gs:(20), which is nasty because 32-bit kernels use %fs for percpu storage. It's even nastier because it means that whether %gs contains userspace state or kernel state while running kernel code depends on whether stackprotector is enabled (this is CONFIG_X86_32_LAZY_GS), and this setting radically changes the way that segment selectors work. Supporting both variants is a maintenance and testing mess. Merely rearranging so that percpu and the stack canary share the same segment would be messy as the 32-bit percpu address layout isn't currently compatible with putting a variable at a fixed offset. Fortunately, GCC 8.1 added options that allow the stack canary to be accessed as %fs:__stack_chk_guard, effectively turning it into an ordinary percpu variable. This lets us get rid of all of the code to manage the stack canary GDT descriptor and the CONFIG_X86_32_LAZY_GS mess. (That name is special. We could use any symbol we want for the %fs-relative mode, but for CONFIG_SMP=n, gcc refuses to let us use any name other than __stack_chk_guard.) Forcibly disable stackprotector on older compilers that don't support the new options and turn the stack canary into a percpu variable. The "lazy GS" approach is now used for all 32-bit configurations. Also makes load_gs_index() work on 32-bit kernels. On 64-bit kernels, it loads the GS selector and updates the user GSBASE accordingly. (This is unchanged.) On 32-bit kernels, it loads the GS selector and updates GSBASE, which is now always the user base. This means that the overall effect is the same on 32-bit and 64-bit, which avoids some ifdeffery. [ bp: Massage commit message. ] Signed-off-by: Andy Lutomirski Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/c0ff7dba14041c7e5d1cae5d4df052f03759bef3.1613243844.git.luto@kernel.org

x86/xen/pvh: Annotate indirect branch as safe

2021-01-26T17:33:02Z

This indirect jump is harmless; annotate it to keep objtool's retpoline validation happy. Cc: Boris Ostrovsky Cc: Juergen Gross Signed-off-by: Josh Poimboeuf Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/4797c72a258b26e06741c58ccd4a75c42db39c1d.1611263462.git.jpoimboe@redhat.com

treewide: Convert macro and uses of section(foo) to section("foo")

2020-10-25T21:51:49Z

Use a more generic form for __section that requires quotes to avoid complications with clang and gcc differences. Remove the quote operator # from compiler_attributes.h __section macro. Convert all unquoted __section(foo) uses to quoted __section("foo"). Also convert __attribute__((section("foo"))) uses to __section("foo") even if the __attribute__ has multiple list entry forms. Conversion done using the script at: https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl Signed-off-by: Joe Perches Reviewed-by: Nick Desaulniers Reviewed-by: Miguel Ojeda Signed-off-by: Linus Torvalds

x86/asm: Make some functions local

2019-10-18T09:34:39Z

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 Signed-off-by: Borislav Petkov Cc: Andy Lutomirski Cc: Andy Shevchenko Cc: Ard Biesheuvel Cc: Boris Ostrovsky Cc: Darren Hart Cc: Greg Kroah-Hartman Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Juergen Gross Cc: linux-arch@vger.kernel.org Cc: linux-efi Cc: linux-efi@vger.kernel.org Cc: Matt Fleming Cc: Peter Zijlstra Cc: platform-driver-x86@vger.kernel.org Cc: Stefano Stabellini Cc: Thomas Gleixner Cc: x86-ml Cc: xen-devel@lists.xenproject.org Link: https://lkml.kernel.org/r/20191011115108.12392-21-jslaby@suse.cz

xen/pvh: Annotate data appropriately

2019-10-18T08:46:06Z

Use the new SYM_DATA_START_LOCAL, and SYM_DATA_END* macros to get: 0000 8 OBJECT LOCAL DEFAULT 6 gdt 0008 32 OBJECT LOCAL DEFAULT 6 gdt_start 0028 0 OBJECT LOCAL DEFAULT 6 gdt_end 0028 256 OBJECT LOCAL DEFAULT 6 early_stack 0128 0 OBJECT LOCAL DEFAULT 6 early_stack Signed-off-by: Jiri Slaby Signed-off-by: Borislav Petkov Reviewed-by: Boris Ostrovsky Cc: Andy Shevchenko Cc: Darren Hart Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Juergen Gross Cc: linux-arch@vger.kernel.org Cc: platform-driver-x86@vger.kernel.org Cc: Stefano Stabellini Cc: Thomas Gleixner Cc: x86-ml Cc: xen-devel@lists.xenproject.org Link: https://lkml.kernel.org/r/20191011115108.12392-15-jslaby@suse.cz

docs: fix broken documentation links

2019-06-08T19:42:13Z

Mostly due to x86 and acpi conversion, several documentation links are still pointing to the old file. Fix them. Signed-off-by: Mauro Carvalho Chehab Reviewed-by: Wolfram Sang Reviewed-by: Sven Van Asbroeck Reviewed-by: Bhupesh Sharma Acked-by: Mark Brown Signed-off-by: Jonathan Corbet