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author | Josh Poimboeuf <jpoimboe@redhat.com> | 2021-01-21 15:29:35 -0600 |
---|---|---|
committer | Josh Poimboeuf <jpoimboe@redhat.com> | 2021-01-26 11:33:04 -0600 |
commit | 125f0b7d24216f37a9683b3899fa45101090f098 (patch) | |
tree | 0c4b301cb4bf8af3928fd579b4a60020a5447e0d /arch/x86 | |
parent | b682369d47df66ebc157426f7eb991c3eec32e7e (diff) | |
download | linux-stable-125f0b7d24216f37a9683b3899fa45101090f098.tar.gz linux-stable-125f0b7d24216f37a9683b3899fa45101090f098.tar.bz2 linux-stable-125f0b7d24216f37a9683b3899fa45101090f098.zip |
x86/power: Move restore_registers() to top of the file
Because restore_registers() is page-aligned, the assembler inexplicably
adds an unreachable jump from after the end of the previous function to
the beginning of restore_registers().
That confuses objtool, understandably. It also creates significant text
fragmentation. As a result, most of the object file is wasted text
(nops).
Move restore_registers() to the beginning of the file to both prevent
the text fragmentation and avoid the dead jump instruction.
$ size /tmp/hibernate_asm_64.before.o /tmp/hibernate_asm_64.after.o
text data bss dec hex filename
4415 0 0 4415 113f /tmp/hibernate_asm_64.before.o
524 0 0 524 20c /tmp/hibernate_asm_64.after.o
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/8c7f634201d26453d73fe55032cbbdc05d004387.1611263462.git.jpoimboe@redhat.com
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/power/hibernate_asm_64.S | 92 |
1 files changed, 46 insertions, 46 deletions
diff --git a/arch/x86/power/hibernate_asm_64.S b/arch/x86/power/hibernate_asm_64.S index 715509d94fa3..91c4602d2b5d 100644 --- a/arch/x86/power/hibernate_asm_64.S +++ b/arch/x86/power/hibernate_asm_64.S @@ -23,6 +23,52 @@ #include <asm/frame.h> #include <asm/nospec-branch.h> + /* code below belongs to the image kernel */ + .align PAGE_SIZE +SYM_FUNC_START(restore_registers) + /* go back to the original page tables */ + movq %r9, %cr3 + + /* Flush TLB, including "global" things (vmalloc) */ + movq mmu_cr4_features(%rip), %rax + movq %rax, %rdx + andq $~(X86_CR4_PGE), %rdx + movq %rdx, %cr4; # turn off PGE + movq %cr3, %rcx; # flush TLB + movq %rcx, %cr3 + movq %rax, %cr4; # turn PGE back on + + /* We don't restore %rax, it must be 0 anyway */ + movq $saved_context, %rax + movq pt_regs_sp(%rax), %rsp + movq pt_regs_bp(%rax), %rbp + movq pt_regs_si(%rax), %rsi + movq pt_regs_di(%rax), %rdi + movq pt_regs_bx(%rax), %rbx + movq pt_regs_cx(%rax), %rcx + movq pt_regs_dx(%rax), %rdx + movq pt_regs_r8(%rax), %r8 + movq pt_regs_r9(%rax), %r9 + movq pt_regs_r10(%rax), %r10 + movq pt_regs_r11(%rax), %r11 + movq pt_regs_r12(%rax), %r12 + movq pt_regs_r13(%rax), %r13 + movq pt_regs_r14(%rax), %r14 + movq pt_regs_r15(%rax), %r15 + pushq pt_regs_flags(%rax) + popfq + + /* Saved in save_processor_state. */ + lgdt saved_context_gdt_desc(%rax) + + xorl %eax, %eax + + /* tell the hibernation core that we've just restored the memory */ + movq %rax, in_suspend(%rip) + + ret +SYM_FUNC_END(restore_registers) + SYM_FUNC_START(swsusp_arch_suspend) movq $saved_context, %rax movq %rsp, pt_regs_sp(%rax) @@ -102,49 +148,3 @@ SYM_CODE_START(core_restore_code) ANNOTATE_RETPOLINE_SAFE jmpq *%r8 SYM_CODE_END(core_restore_code) - - /* code below belongs to the image kernel */ - .align PAGE_SIZE -SYM_FUNC_START(restore_registers) - /* go back to the original page tables */ - movq %r9, %cr3 - - /* Flush TLB, including "global" things (vmalloc) */ - movq mmu_cr4_features(%rip), %rax - movq %rax, %rdx - andq $~(X86_CR4_PGE), %rdx - movq %rdx, %cr4; # turn off PGE - movq %cr3, %rcx; # flush TLB - movq %rcx, %cr3 - movq %rax, %cr4; # turn PGE back on - - /* We don't restore %rax, it must be 0 anyway */ - movq $saved_context, %rax - movq pt_regs_sp(%rax), %rsp - movq pt_regs_bp(%rax), %rbp - movq pt_regs_si(%rax), %rsi - movq pt_regs_di(%rax), %rdi - movq pt_regs_bx(%rax), %rbx - movq pt_regs_cx(%rax), %rcx - movq pt_regs_dx(%rax), %rdx - movq pt_regs_r8(%rax), %r8 - movq pt_regs_r9(%rax), %r9 - movq pt_regs_r10(%rax), %r10 - movq pt_regs_r11(%rax), %r11 - movq pt_regs_r12(%rax), %r12 - movq pt_regs_r13(%rax), %r13 - movq pt_regs_r14(%rax), %r14 - movq pt_regs_r15(%rax), %r15 - pushq pt_regs_flags(%rax) - popfq - - /* Saved in save_processor_state. */ - lgdt saved_context_gdt_desc(%rax) - - xorl %eax, %eax - - /* tell the hibernation core that we've just restored the memory */ - movq %rax, in_suspend(%rip) - - ret -SYM_FUNC_END(restore_registers) |