Messages in this thread Patch in this message | | | From | Lai Jiangshan <> | Subject | [PATCH V5 48/50] x86/entry: Remove the unused ASM macros | Date | Wed, 10 Nov 2021 19:57:34 +0800 |
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From: Lai Jiangshan <laijs@linux.alibaba.com>
They are implemented and used in C code. The ASM version is not needed any more.
FENCE_SWAPGS_USER_ENTRY is not removed because it is still being used in the nmi userspace path. It could be possible to be removed in future entry code enhancement.
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> --- arch/x86/entry/calling.h | 99 ---------------------------------------- 1 file changed, 99 deletions(-)
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h index 9065c31d2875..d42012fc694d 100644 --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -210,53 +210,6 @@ For 32-bit we have the following conventions - kernel is built with popq %rax .endm -.macro SAVE_AND_SWITCH_TO_KERNEL_CR3 scratch_reg:req save_reg:req - ALTERNATIVE "jmp .Ldone_\@", "", X86_FEATURE_PTI - movq %cr3, \scratch_reg - movq \scratch_reg, \save_reg - /* - * Test the user pagetable bit. If set, then the user page tables - * are active. If clear CR3 already has the kernel page table - * active. - */ - bt $PTI_USER_PGTABLE_BIT, \scratch_reg - jnc .Ldone_\@ - - ADJUST_KERNEL_CR3 \scratch_reg - movq \scratch_reg, %cr3 - -.Ldone_\@: -.endm - -.macro RESTORE_CR3 scratch_reg:req save_reg:req - ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_PTI - - /* No need to restore when the saved CR3 is kernel CR3. */ - bt $PTI_USER_PGTABLE_BIT, \save_reg - jnc .Lend_\@ - - ALTERNATIVE "jmp .Lwrcr3_\@", "", X86_FEATURE_PCID - - /* - * Check if there's a pending flush for the user ASID we're - * about to set. - */ - movq \save_reg, \scratch_reg - andq $(0x7FF), \scratch_reg - bt \scratch_reg, THIS_CPU_user_pcid_flush_mask - jnc .Lnoflush_\@ - - btr \scratch_reg, THIS_CPU_user_pcid_flush_mask - jmp .Lwrcr3_\@ - -.Lnoflush_\@: - SET_NOFLUSH_BIT \save_reg - -.Lwrcr3_\@: - movq \save_reg, %cr3 -.Lend_\@: -.endm - #else /* CONFIG_PAGE_TABLE_ISOLATION=n: */ .macro SWITCH_TO_KERNEL_CR3 scratch_reg:req @@ -265,10 +218,6 @@ For 32-bit we have the following conventions - kernel is built with .endm .macro SWITCH_TO_USER_CR3_STACK scratch_reg:req .endm -.macro SAVE_AND_SWITCH_TO_KERNEL_CR3 scratch_reg:req save_reg:req -.endm -.macro RESTORE_CR3 scratch_reg:req save_reg:req -.endm #endif @@ -277,17 +226,10 @@ For 32-bit we have the following conventions - kernel is built with * * FENCE_SWAPGS_USER_ENTRY is used in the user entry swapgs code path, to * prevent a speculative swapgs when coming from kernel space. - * - * FENCE_SWAPGS_KERNEL_ENTRY is used in the kernel entry non-swapgs code path, - * to prevent the swapgs from getting speculatively skipped when coming from - * user space. */ .macro FENCE_SWAPGS_USER_ENTRY ALTERNATIVE "", "lfence", X86_FEATURE_FENCE_SWAPGS_USER .endm -.macro FENCE_SWAPGS_KERNEL_ENTRY - ALTERNATIVE "", "lfence", X86_FEATURE_FENCE_SWAPGS_KERNEL -.endm .macro STACKLEAK_ERASE_NOCLOBBER #ifdef CONFIG_GCC_PLUGIN_STACKLEAK @@ -297,12 +239,6 @@ For 32-bit we have the following conventions - kernel is built with #endif .endm -.macro SAVE_AND_SET_GSBASE scratch_reg:req save_reg:req - rdgsbase \save_reg - GET_PERCPU_BASE \scratch_reg - wrgsbase \scratch_reg -.endm - #else /* CONFIG_X86_64 */ # undef UNWIND_HINT_IRET_REGS # define UNWIND_HINT_IRET_REGS @@ -313,38 +249,3 @@ For 32-bit we have the following conventions - kernel is built with call stackleak_erase #endif .endm - -#ifdef CONFIG_SMP - -/* - * CPU/node NR is loaded from the limit (size) field of a special segment - * descriptor entry in GDT. - */ -.macro LOAD_CPU_AND_NODE_SEG_LIMIT reg:req - movq $__CPUNODE_SEG, \reg - lsl \reg, \reg -.endm - -/* - * Fetch the per-CPU GSBASE value for this processor and put it in @reg. - * We normally use %gs for accessing per-CPU data, but we are setting up - * %gs here and obviously can not use %gs itself to access per-CPU data. - * - * Do not use RDPID, because KVM loads guest's TSC_AUX on vm-entry and - * may not restore the host's value until the CPU returns to userspace. - * Thus the kernel would consume a guest's TSC_AUX if an NMI arrives - * while running KVM's run loop. - */ -.macro GET_PERCPU_BASE reg:req - LOAD_CPU_AND_NODE_SEG_LIMIT \reg - andq $VDSO_CPUNODE_MASK, \reg - movq __per_cpu_offset(, \reg, 8), \reg -.endm - -#else - -.macro GET_PERCPU_BASE reg:req - movq pcpu_unit_offsets(%rip), \reg -.endm - -#endif /* CONFIG_SMP */ -- 2.19.1.6.gb485710b
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