The following commit has been merged into the objtool/core branch of tip: Commit-ID: 0a53c9acf4da51a75392b0b543ce5eaae78a567f Gitweb: https://git.kernel.org/tip/0a53c9acf4da51a75392b0b543ce5eaae78a567f Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx> AuthorDate: Thu, 24 Jun 2021 11:41:13 +02:00 Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CommitterDate: Fri, 17 Sep 2021 13:11:50 +02:00 x86/xen: Make read_cr2() noinstr 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@xxxxxxxxxxxxx> Reviewed-by: Juergen Gross <jgross@xxxxxxxx> Link: https://lore.kernel.org/r/20210624095148.500331616@xxxxxxxxxxxxx --- arch/x86/include/asm/paravirt.h | 2 +- arch/x86/kernel/paravirt.c | 7 ++++++- arch/x86/xen/xen-asm.S | 2 ++ 3 files changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index a13a9a3..8878065 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -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;", diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index 04cafc0..e351014 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -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, diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S index 1e62644..aef4a1e 100644 --- a/arch/x86/xen/xen-asm.S +++ b/arch/x86/xen/xen-asm.S @@ -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)
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