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authorIngo Molnar <[email protected]>2019-04-25 10:10:12 +0200
committerIngo Molnar <[email protected]>2019-04-25 12:00:44 +0200
commitfc93dfd9345bb8b29a62b21cb0447dd1a3815f91 (patch)
tree3a8a19683e0b205facc4725d0a3236b7d9589d1b
parent0b9d2fc1d0d628c94c6866a2ed3005c6730db512 (diff)
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 <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Juergen Gross <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
-rw-r--r--arch/x86/kernel/paravirt_patch.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kernel/paravirt_patch.c b/arch/x86/kernel/paravirt_patch.c
index 60e7a5e236c0..37b1d43d1e17 100644
--- a/arch/x86/kernel/paravirt_patch.c
+++ b/arch/x86/kernel/paravirt_patch.c
@@ -21,11 +21,11 @@
struct patch_xxl {
const unsigned char irq_irq_disable[1];
const unsigned char irq_irq_enable[1];
- const unsigned char irq_restore_fl[2];
const unsigned char irq_save_fl[2];
const unsigned char mmu_read_cr2[3];
const unsigned char mmu_read_cr3[3];
const unsigned char mmu_write_cr3[3];
+ const unsigned char irq_restore_fl[2];
# ifdef CONFIG_X86_64
const unsigned char cpu_wbinvd[2];
const unsigned char cpu_usergs_sysret64[6];
@@ -43,16 +43,16 @@ static const struct patch_xxl patch_data_xxl = {
.mmu_read_cr2 = { 0x0f, 0x20, 0xd0 }, // mov %cr2, %[re]ax
.mmu_read_cr3 = { 0x0f, 0x20, 0xd8 }, // mov %cr3, %[re]ax
# ifdef CONFIG_X86_64
- .irq_restore_fl = { 0x57, 0x9d }, // push %rdi; popfq
.mmu_write_cr3 = { 0x0f, 0x22, 0xdf }, // mov %rdi, %cr3
+ .irq_restore_fl = { 0x57, 0x9d }, // push %rdi; popfq
.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
# else
- .irq_restore_fl = { 0x50, 0x9d }, // push %eax; popf
.mmu_write_cr3 = { 0x0f, 0x22, 0xd8 }, // mov %eax, %cr3
+ .irq_restore_fl = { 0x50, 0x9d }, // push %eax; popf
.cpu_iret = { 0xcf }, // iret
# endif
};