Commits
Ingo Molnar committed fc93dfd9345
x86/paravirt: Match paravirt patchlet field definition ordering to initialization ordering
Here's the objdump -D output of the PATCH_XXL data table:
0000000000000010 <patch_data_xxl>:
10: fa cli
11: fb sti
12: 57 push %rdi
13: 9d popfq
14: 9c pushfq
15: 58 pop %rax
16: 0f 20 d0 mov %cr2,%rax
19: 0f 20 d8 mov %cr3,%rax
1c: 0f 22 df mov %rdi,%cr3
1f: 0f 09 wbinvd
21: 0f 01 f8 swapgs
24: 48 0f 07 sysretq
27: 0f 01 f8 swapgs
2a: 48 89 f8 mov %rdi,%rax
Note how this doesn't match up to the source code:
static const struct patch_xxl patch_data_xxl = {
.irq_irq_disable = { 0xfa }, // cli
.irq_irq_enable = { 0xfb }, // sti
.irq_save_fl = { 0x9c, 0x58 }, // pushf; pop %[re]ax
.mmu_read_cr2 = { 0x0f, 0x20, 0xd0 }, // mov %cr2, %[re]ax
.mmu_read_cr3 = { 0x0f, 0x20, 0xd8 }, // mov %cr3, %[re]ax
.irq_restore_fl = { 0x57, 0x9d }, // push %rdi; popfq
.mmu_write_cr3 = { 0x0f, 0x22, 0xdf }, // mov %rdi, %cr3
.cpu_wbinvd = { 0x0f, 0x09 }, // wbinvd
.cpu_usergs_sysret64 = { 0x0f, 0x01, 0xf8,
0x48, 0x0f, 0x07 }, // swapgs; sysretq
.cpu_swapgs = { 0x0f, 0x01, 0xf8 }, // swapgs
.mov64 = { 0x48, 0x89, 0xf8 }, // mov %rdi, %rax
.irq_restore_fl = { 0x50, 0x9d }, // push %eax; popf
.mmu_write_cr3 = { 0x0f, 0x22, 0xd8 }, // mov %eax, %cr3
.cpu_iret = { 0xcf }, // iret
};
Note how they are reordered: in the generated code .irq_restore_fl comes
before .irq_save_fl, etc. This is because the field ordering in struct
patch_xxl does not match the initialization ordering of patch_data_xxl.
Match up the initialization order with the definition order - this makes
the disassembly easily reviewable:
0000000000000010 <patch_data_xxl>:
10: fa cli
11: fb sti
12: 9c pushfq
13: 58 pop %rax
14: 0f 20 d0 mov %cr2,%rax
17: 0f 20 d8 mov %cr3,%rax
1a: 0f 22 df mov %rdi,%cr3
1d: 57 push %rdi
1e: 9d popfq
1f: 0f 09 wbinvd
21: 0f 01 f8 swapgs
24: 48 0f 07 sysretq
27: 0f 01 f8 swapgs
2a: 48 89 f8 mov %rdi,%rax
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20190425081012.GA115378@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>