mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-19 17:11:03 +00:00
Code Issues Releases Wiki Activity

x86/xen: Make read_cr2() noinstr

Browse source 
vmlinux.o: warning: objtool: pv_ops[41]: native_read_cr2
vmlinux.o: warning: objtool: pv_ops[41]: xen_read_cr2
vmlinux.o: warning: objtool: pv_ops[41]: xen_read_cr2_direct
vmlinux.o: warning: objtool: exc_double_fault()+0x15: call to pv_ops[41]() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20210624095148.500331616@infradead.org
This commit is contained in:
Peter Zijlstra 2021-06-24 11:41:13 +02:00
parent eac46b323b
commit 0a53c9acf4
3 changed files with 9 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
arch/x86/include/asm/paravirt.h
View file

@ -133,7 +133,7 @@ static inline void write_cr0(unsigned long x)
PVOP_VCALL1(cpu.write_cr0, x);
}
static inline unsigned long read_cr2(void)
static __always_inline unsigned long read_cr2(void)
{
return PVOP_ALT_CALLEE0(unsigned long, mmu.read_cr2,
"mov %%cr2, %%rax;",

7
arch/x86/kernel/paravirt.c
View file

@ -218,6 +218,11 @@ void paravirt_end_context_switch(struct task_struct *next)
if (test_and_clear_ti_thread_flag(task_thread_info(next), TIF_LAZY_MMU_UPDATES))
arch_enter_lazy_mmu_mode();
}
static noinstr unsigned long pv_native_read_cr2(void)
{
return native_read_cr2();
}
#endif
enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
@ -298,7 +303,7 @@ struct paravirt_patch_template pv_ops = {
.mmu.exit_mmap = paravirt_nop,
#ifdef CONFIG_PARAVIRT_XXL
.mmu.read_cr2 = __PV_IS_CALLEE_SAVE(native_read_cr2),
.mmu.read_cr2 = __PV_IS_CALLEE_SAVE(pv_native_read_cr2),
.mmu.write_cr2 = native_write_cr2,
.mmu.read_cr3 = __native_read_cr3,
.mmu.write_cr3 = native_write_cr3,

2
arch/x86/xen/xen-asm.S
View file

@ -102,6 +102,7 @@ SYM_FUNC_START(check_events)
ret
SYM_FUNC_END(check_events)
.pushsection .noinstr.text, "ax"
SYM_FUNC_START(xen_read_cr2)
FRAME_BEGIN
_ASM_MOV PER_CPU_VAR(xen_vcpu), %_ASM_AX
@ -116,6 +117,7 @@ SYM_FUNC_START(xen_read_cr2_direct)
FRAME_END
ret
SYM_FUNC_END(xen_read_cr2_direct);
.popsection
.macro xen_pv_trap name
SYM_CODE_START(xen_\name)