4.14-stable review patch. If anyone has any objections, please let me know.
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From: Dominik Brodowski linux@dominikbrodowski.net
commit 502af0d70843c2a9405d7ba1f79b4b0305aaf5f5 upstream.
The two special, opencoded cases for POP_C_REGS can be handled by ASM macros.
Signed-off-by: Dominik Brodowski linux@dominikbrodowski.net Cc: Andy Lutomirski luto@kernel.org Cc: Borislav Petkov bp@alien8.de Cc: Brian Gerst brgerst@gmail.com Cc: Denys Vlasenko dvlasenk@redhat.com Cc: H. Peter Anvin hpa@zytor.com Cc: Josh Poimboeuf jpoimboe@redhat.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Cc: dan.j.williams@intel.com Link: http://lkml.kernel.org/r/20180211104949.12992-3-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/entry/calling.h | 15 +++++++++++---- arch/x86/entry/entry_64.S | 26 ++++---------------------- 2 files changed, 15 insertions(+), 26 deletions(-)
--- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -139,25 +139,32 @@ For 32-bit we have the following convent xorq %r15, %r15 .endm
- .macro POP_EXTRA_REGS + .macro POP_REGS pop_rdi=1 skip_r11rcx=0 popq %r15 popq %r14 popq %r13 popq %r12 popq %rbp popq %rbx - .endm - - .macro POP_C_REGS + .if \skip_r11rcx + popq %rsi + .else popq %r11 + .endif popq %r10 popq %r9 popq %r8 popq %rax + .if \skip_r11rcx + popq %rsi + .else popq %rcx + .endif popq %rdx popq %rsi + .if \pop_rdi popq %rdi + .endif .endm
.macro icebp --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -330,15 +330,7 @@ GLOBAL(entry_SYSCALL_64_after_hwframe) syscall_return_via_sysret: /* rcx and r11 are already restored (see code above) */ UNWIND_HINT_EMPTY - POP_EXTRA_REGS - popq %rsi /* skip r11 */ - popq %r10 - popq %r9 - popq %r8 - popq %rax - popq %rsi /* skip rcx */ - popq %rdx - popq %rsi + POP_REGS pop_rdi=0 skip_r11rcx=1
/* * Now all regs are restored except RSP and RDI. @@ -631,15 +623,7 @@ GLOBAL(swapgs_restore_regs_and_return_to ud2 1: #endif - POP_EXTRA_REGS - popq %r11 - popq %r10 - popq %r9 - popq %r8 - popq %rax - popq %rcx - popq %rdx - popq %rsi + POP_REGS pop_rdi=0
/* * The stack is now user RDI, orig_ax, RIP, CS, EFLAGS, RSP, SS. @@ -697,8 +681,7 @@ GLOBAL(restore_regs_and_return_to_kernel ud2 1: #endif - POP_EXTRA_REGS - POP_C_REGS + POP_REGS addq $8, %rsp /* skip regs->orig_ax */ INTERRUPT_RETURN
@@ -1655,8 +1638,7 @@ end_repeat_nmi: nmi_swapgs: SWAPGS_UNSAFE_STACK nmi_restore: - POP_EXTRA_REGS - POP_C_REGS + POP_REGS
/* * Skip orig_ax and the "outermost" frame to point RSP at the "iret"