summaryrefslogtreecommitdiff
path: root/arch/x86/kernel
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2020-03-31 01:32:23 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-03-31 01:32:23 +0300
commitd937a6dfc9428f470c3ce4d459c390944ddef538 (patch)
treeab23a45b81fea218ada4794f0f74a93c9996f992 /arch/x86/kernel
parent2ce94bc4e056d3e48291aac87a95ebd2a86348ba (diff)
parent350994bf95414d6da67a72f27d7ac3832ce3725d (diff)
downloadlinux-d937a6dfc9428f470c3ce4d459c390944ddef538.tar.xz
Merge branch 'core-objtool-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool updates from Ingo Molnar: "The biggest changes in this cycle were the vmlinux.o optimizations by Peter Zijlstra, which are preparatory and optimization work to run objtool against the much richer vmlinux.o object file, to perform new, whole-program section based logic. That work exposed a handful of problems with the existing code, which fixes and optimizations are merged here. The complete 'vmlinux.o and noinstr' work is still work in progress, targeted for v5.8. There's also assorted fixes and enhancements from Josh Poimboeuf. In particular I'd like to draw attention to commit 644592d328370, which turns fatal objtool errors into failed kernel builds. This behavior is IMO now justified on multiple grounds (it's easy currently to not notice an essentially corrupted kernel build), and the commit has been in -next testing for several weeks, but there could still be build failures with old or weird toolchains. Should that be widespread or high profile enough then I'd suggest a quick revert, to not hold up the merge window" * 'core-objtool-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits) objtool: Re-arrange validate_functions() objtool: Optimize find_rela_by_dest_range() objtool: Delete cleanup() objtool: Optimize read_sections() objtool: Optimize find_symbol_by_name() objtool: Resize insn_hash objtool: Rename find_containing_func() objtool: Optimize find_symbol_*() and read_symbols() objtool: Optimize find_section_by_name() objtool: Optimize find_section_by_index() objtool: Add a statistics mode objtool: Optimize find_symbol_by_index() x86/kexec: Make relocate_kernel_64.S objtool clean x86/kexec: Use RIP relative addressing objtool: Rename func_for_each_insn_all() objtool: Rename func_for_each_insn() objtool: Introduce validate_return() objtool: Improve call destination function detection objtool: Fix clang switch table edge case objtool: Add relocation check for alternative sections ...
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/Makefile1
-rw-r--r--arch/x86/kernel/relocate_kernel_64.S12
2 files changed, 8 insertions, 5 deletions
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 9b294c13809a..8be5926cce51 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -28,7 +28,6 @@ KASAN_SANITIZE_dumpstack_$(BITS).o := n
KASAN_SANITIZE_stacktrace.o := n
KASAN_SANITIZE_paravirt.o := n
-OBJECT_FILES_NON_STANDARD_relocate_kernel_$(BITS).o := y
OBJECT_FILES_NON_STANDARD_test_nx.o := y
OBJECT_FILES_NON_STANDARD_paravirt_patch.o := y
diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S
index ef3ba99068d3..a4d9a261425b 100644
--- a/arch/x86/kernel/relocate_kernel_64.S
+++ b/arch/x86/kernel/relocate_kernel_64.S
@@ -9,6 +9,8 @@
#include <asm/kexec.h>
#include <asm/processor-flags.h>
#include <asm/pgtable_types.h>
+#include <asm/nospec-branch.h>
+#include <asm/unwind_hints.h>
/*
* Must be relocatable PIC code callable as a C function
@@ -39,6 +41,7 @@
.align PAGE_SIZE
.code64
SYM_CODE_START_NOALIGN(relocate_kernel)
+ UNWIND_HINT_EMPTY
/*
* %rdi indirection_page
* %rsi page_list
@@ -105,6 +108,7 @@ SYM_CODE_START_NOALIGN(relocate_kernel)
SYM_CODE_END(relocate_kernel)
SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
+ UNWIND_HINT_EMPTY
/* set return address to 0 if not preserving context */
pushq $0
/* store the start address on the stack */
@@ -192,14 +196,12 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
1:
popq %rdx
leaq PAGE_SIZE(%r10), %rsp
+ ANNOTATE_RETPOLINE_SAFE
call *%rdx
/* get the re-entry point of the peer system */
movq 0(%rsp), %rbp
- call 1f
-1:
- popq %r8
- subq $(1b - relocate_kernel), %r8
+ leaq relocate_kernel(%rip), %r8
movq CP_PA_SWAP_PAGE(%r8), %r10
movq CP_PA_BACKUP_PAGES_MAP(%r8), %rdi
movq CP_PA_TABLE_PAGE(%r8), %rax
@@ -212,6 +214,7 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
SYM_CODE_END(identity_mapped)
SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped)
+ UNWIND_HINT_EMPTY
movq RSP(%r8), %rsp
movq CR4(%r8), %rax
movq %rax, %cr4
@@ -233,6 +236,7 @@ SYM_CODE_END(virtual_mapped)
/* Do the copies */
SYM_CODE_START_LOCAL_NOALIGN(swap_pages)
+ UNWIND_HINT_EMPTY
movq %rdi, %rcx /* Put the page_list in %rcx */
xorl %edi, %edi
xorl %esi, %esi