[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen stable-4.15] x86/entry: Introduce EFRAME_* constants
commit e7a37b9b2c86a17869a201955038d33f23f33b57 Author: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> AuthorDate: Sat Jan 27 17:52:09 2024 +0000 Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> CommitDate: Tue Mar 12 16:37:44 2024 +0000 x86/entry: Introduce EFRAME_* constants restore_all_guest() does a lot of manipulation of the stack after popping the GPRs, and uses raw %rsp displacements to do so. Also, almost all entrypaths use raw %rsp displacements prior to pushing GPRs. Provide better mnemonics, to aid readability and reduce the chance of errors when editing. No functional change. The resulting binary is identical. Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx> (cherry picked from commit 37541208f119a9c552c6c6c3246ea61be0d44035) --- xen/arch/x86/x86_64/asm-offsets.c | 17 ++++++++++ xen/arch/x86/x86_64/compat/entry.S | 4 +-- xen/arch/x86/x86_64/entry.S | 68 +++++++++++++++++++------------------- 3 files changed, 53 insertions(+), 36 deletions(-) diff --git a/xen/arch/x86/x86_64/asm-offsets.c b/xen/arch/x86/x86_64/asm-offsets.c index 6dbf3bf697..9d105161db 100644 --- a/xen/arch/x86/x86_64/asm-offsets.c +++ b/xen/arch/x86/x86_64/asm-offsets.c @@ -51,6 +51,23 @@ void __dummy__(void) OFFSET(UREGS_kernel_sizeof, struct cpu_user_regs, es); BLANK(); + /* + * EFRAME_* is for the entry/exit logic where %rsp is pointing at + * UREGS_error_code and GPRs are still/already guest values. + */ +#define OFFSET_EF(sym, mem) \ + DEFINE(sym, offsetof(struct cpu_user_regs, mem) - \ + offsetof(struct cpu_user_regs, error_code)) + + OFFSET_EF(EFRAME_entry_vector, entry_vector); + OFFSET_EF(EFRAME_rip, rip); + OFFSET_EF(EFRAME_cs, cs); + OFFSET_EF(EFRAME_eflags, eflags); + OFFSET_EF(EFRAME_rsp, rsp); + BLANK(); + +#undef OFFSET_EF + OFFSET(VCPU_processor, struct vcpu, processor); OFFSET(VCPU_domain, struct vcpu, domain); OFFSET(VCPU_vcpu_info, struct vcpu, vcpu_info); diff --git a/xen/arch/x86/x86_64/compat/entry.S b/xen/arch/x86/x86_64/compat/entry.S index cde7702b4c..20603ec4af 100644 --- a/xen/arch/x86/x86_64/compat/entry.S +++ b/xen/arch/x86/x86_64/compat/entry.S @@ -17,7 +17,7 @@ ENTRY(entry_int82) ENDBR64 ALTERNATIVE "", clac, X86_FEATURE_XEN_SMAP pushq $0 - movl $HYPERCALL_VECTOR, 4(%rsp) + movl $HYPERCALL_VECTOR, EFRAME_entry_vector(%rsp) SAVE_ALL compat=1 /* DPL1 gate, restricted to 32bit PV guests only. */ SPEC_CTRL_ENTRY_FROM_PV /* Req: %rsp=regs/cpuinfo, %rdx=0, Clob: acd */ @@ -214,7 +214,7 @@ ENTRY(cstar_enter) pushq $FLAT_USER_CS32 pushq %rcx pushq $0 - movl $TRAP_syscall, 4(%rsp) + movl $TRAP_syscall, EFRAME_entry_vector(%rsp) SAVE_ALL SPEC_CTRL_ENTRY_FROM_PV /* Req: %rsp=regs/cpuinfo, %rdx=0, Clob: acd */ diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S index a086349841..fe052d2792 100644 --- a/xen/arch/x86/x86_64/entry.S +++ b/xen/arch/x86/x86_64/entry.S @@ -190,15 +190,15 @@ restore_all_guest: SPEC_CTRL_EXIT_TO_PV /* Req: a=spec_ctrl %rsp=regs/cpuinfo, Clob: cd */ RESTORE_ALL - testw $TRAP_syscall,4(%rsp) + testw $TRAP_syscall, EFRAME_entry_vector(%rsp) jz iret_exit_to_guest - movq 24(%rsp),%r11 # RFLAGS + mov EFRAME_eflags(%rsp), %r11 andq $~(X86_EFLAGS_IOPL | X86_EFLAGS_VM), %r11 orq $X86_EFLAGS_IF,%r11 /* Don't use SYSRET path if the return address is not canonical. */ - movq 8(%rsp),%rcx + mov EFRAME_rip(%rsp), %rcx sarq $47,%rcx incl %ecx cmpl $1,%ecx @@ -213,20 +213,20 @@ restore_all_guest: ALTERNATIVE "", rag_clrssbsy, X86_FEATURE_XEN_SHSTK #endif - movq 8(%rsp), %rcx # RIP - cmpw $FLAT_USER_CS32,16(%rsp)# CS - movq 32(%rsp),%rsp # RSP + mov EFRAME_rip(%rsp), %rcx + cmpw $FLAT_USER_CS32, EFRAME_cs(%rsp) + mov EFRAME_rsp(%rsp), %rsp je 1f sysretq 1: sysretl ALIGN .Lrestore_rcx_iret_exit_to_guest: - movq 8(%rsp), %rcx # RIP + mov EFRAME_rip(%rsp), %rcx /* No special register assumptions. */ iret_exit_to_guest: - andl $~(X86_EFLAGS_IOPL | X86_EFLAGS_VM), 24(%rsp) - orl $X86_EFLAGS_IF,24(%rsp) + andl $~(X86_EFLAGS_IOPL | X86_EFLAGS_VM), EFRAME_eflags(%rsp) + orl $X86_EFLAGS_IF, EFRAME_eflags(%rsp) addq $8,%rsp .Lft0: iretq _ASM_PRE_EXTABLE(.Lft0, handle_exception) @@ -257,7 +257,7 @@ ENTRY(lstar_enter) pushq $FLAT_KERNEL_CS64 pushq %rcx pushq $0 - movl $TRAP_syscall, 4(%rsp) + movl $TRAP_syscall, EFRAME_entry_vector(%rsp) SAVE_ALL SPEC_CTRL_ENTRY_FROM_PV /* Req: %rsp=regs/cpuinfo, %rdx=0, Clob: acd */ @@ -295,7 +295,7 @@ GLOBAL(sysenter_eflags_saved) pushq $3 /* ring 3 null cs */ pushq $0 /* null rip */ pushq $0 - movl $TRAP_syscall, 4(%rsp) + movl $TRAP_syscall, EFRAME_entry_vector(%rsp) SAVE_ALL SPEC_CTRL_ENTRY_FROM_PV /* Req: %rsp=regs/cpuinfo, %rdx=0, Clob: acd */ @@ -347,7 +347,7 @@ ENTRY(int80_direct_trap) ENDBR64 ALTERNATIVE "", clac, X86_FEATURE_XEN_SMAP pushq $0 - movl $0x80, 4(%rsp) + movl $0x80, EFRAME_entry_vector(%rsp) SAVE_ALL SPEC_CTRL_ENTRY_FROM_PV /* Req: %rsp=regs/cpuinfo, %rdx=0, Clob: acd */ @@ -650,7 +650,7 @@ ENTRY(common_interrupt) ENTRY(page_fault) ENDBR64 - movl $TRAP_page_fault,4(%rsp) + movl $TRAP_page_fault, EFRAME_entry_vector(%rsp) /* No special register assumptions. */ GLOBAL(handle_exception) ALTERNATIVE "", clac, X86_FEATURE_XEN_SMAP @@ -790,90 +790,90 @@ FATAL_exception_with_ints_disabled: ENTRY(divide_error) ENDBR64 pushq $0 - movl $TRAP_divide_error,4(%rsp) + movl $TRAP_divide_error, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(coprocessor_error) ENDBR64 pushq $0 - movl $TRAP_copro_error,4(%rsp) + movl $TRAP_copro_error, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(simd_coprocessor_error) ENDBR64 pushq $0 - movl $TRAP_simd_error,4(%rsp) + movl $TRAP_simd_error, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(device_not_available) ENDBR64 pushq $0 - movl $TRAP_no_device,4(%rsp) + movl $TRAP_no_device, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(debug) ENDBR64 pushq $0 - movl $TRAP_debug,4(%rsp) + movl $TRAP_debug, EFRAME_entry_vector(%rsp) jmp handle_ist_exception ENTRY(int3) ENDBR64 pushq $0 - movl $TRAP_int3,4(%rsp) + movl $TRAP_int3, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(overflow) ENDBR64 pushq $0 - movl $TRAP_overflow,4(%rsp) + movl $TRAP_overflow, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(bounds) ENDBR64 pushq $0 - movl $TRAP_bounds,4(%rsp) + movl $TRAP_bounds, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(invalid_op) ENDBR64 pushq $0 - movl $TRAP_invalid_op,4(%rsp) + movl $TRAP_invalid_op, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(invalid_TSS) ENDBR64 - movl $TRAP_invalid_tss,4(%rsp) + movl $TRAP_invalid_tss, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(segment_not_present) ENDBR64 - movl $TRAP_no_segment,4(%rsp) + movl $TRAP_no_segment, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(stack_segment) ENDBR64 - movl $TRAP_stack_error,4(%rsp) + movl $TRAP_stack_error, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(general_protection) ENDBR64 - movl $TRAP_gp_fault,4(%rsp) + movl $TRAP_gp_fault, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(alignment_check) ENDBR64 - movl $TRAP_alignment_check,4(%rsp) + movl $TRAP_alignment_check, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(entry_CP) ENDBR64 - movl $X86_EXC_CP, 4(%rsp) + movl $X86_EXC_CP, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(double_fault) ENDBR64 - movl $TRAP_double_fault,4(%rsp) + movl $TRAP_double_fault, EFRAME_entry_vector(%rsp) /* Set AC to reduce chance of further SMAP faults */ ALTERNATIVE "", stac, X86_FEATURE_XEN_SMAP SAVE_ALL @@ -899,7 +899,7 @@ ENTRY(double_fault) .pushsection .init.text, "ax", @progbits ENTRY(early_page_fault) ENDBR64 - movl $TRAP_page_fault,4(%rsp) + movl $TRAP_page_fault, EFRAME_entry_vector(%rsp) SAVE_ALL movq %rsp,%rdi call do_early_page_fault @@ -909,7 +909,7 @@ ENTRY(early_page_fault) ENTRY(nmi) ENDBR64 pushq $0 - movl $TRAP_nmi,4(%rsp) + movl $TRAP_nmi, EFRAME_entry_vector(%rsp) handle_ist_exception: ALTERNATIVE "", clac, X86_FEATURE_XEN_SMAP SAVE_ALL @@ -1011,7 +1011,7 @@ handle_ist_exception: ENTRY(machine_check) ENDBR64 pushq $0 - movl $TRAP_machine_check,4(%rsp) + movl $TRAP_machine_check, EFRAME_entry_vector(%rsp) jmp handle_ist_exception /* No op trap handler. Required for kexec crash path. */ @@ -1048,7 +1048,7 @@ autogen_stubs: /* Automatically generated stubs. */ 1: ENDBR64 pushq $0 - movb $vec,4(%rsp) + movb $vec, EFRAME_entry_vector(%rsp) jmp common_interrupt entrypoint 1b @@ -1062,7 +1062,7 @@ autogen_stubs: /* Automatically generated stubs. */ test $8,%spl /* 64bit exception frames are 16 byte aligned, but the word */ jz 2f /* size is 8 bytes. Check whether the processor gave us an */ pushq $0 /* error code, and insert an empty one if not. */ -2: movb $vec,4(%rsp) +2: movb $vec, EFRAME_entry_vector(%rsp) jmp handle_exception entrypoint 1b -- generated by git-patchbot for /home/xen/git/xen.git#stable-4.15
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