From 748e4f3d702def1a4bff191e0cf93b6a05340f01 Mon Sep 17 00:00:00 2001 From: hc <hc@nodka.com> Date: Fri, 10 May 2024 07:41:34 +0000 Subject: [PATCH] add gpio led uart --- kernel/arch/x86/entry/entry_64_compat.S | 118 +++++++++++++++++++++++++++++++++-------------------------- 1 files changed, 66 insertions(+), 52 deletions(-) diff --git a/kernel/arch/x86/entry/entry_64_compat.S b/kernel/arch/x86/entry/entry_64_compat.S index 40d2834..4d637a9 100644 --- a/kernel/arch/x86/entry/entry_64_compat.S +++ b/kernel/arch/x86/entry/entry_64_compat.S @@ -4,7 +4,6 @@ * * Copyright 2000-2002 Andi Kleen, SuSE Labs. */ -#include "calling.h" #include <asm/asm-offsets.h> #include <asm/current.h> #include <asm/errno.h> @@ -14,8 +13,11 @@ #include <asm/irqflags.h> #include <asm/asm.h> #include <asm/smap.h> +#include <asm/nospec-branch.h> #include <linux/linkage.h> #include <linux/err.h> + +#include "calling.h" .section .entry.text, "ax" @@ -46,14 +48,31 @@ * ebp user stack * 0(%ebp) arg6 */ -ENTRY(entry_SYSENTER_compat) +SYM_CODE_START(entry_SYSENTER_compat) + UNWIND_HINT_ENTRY /* Interrupts are off on entry. */ SWAPGS - /* We are about to clobber %rsp anyway, clobbering here is OK */ - SWITCH_TO_KERNEL_CR3 scratch_reg=%rsp + pushq %rax + SWITCH_TO_KERNEL_CR3 scratch_reg=%rax + popq %rax movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp + + /* Construct struct pt_regs on stack */ + pushq $__USER32_DS /* pt_regs->ss */ + pushq $0 /* pt_regs->sp = 0 (placeholder) */ + + /* + * Push flags. This is nasty. First, interrupts are currently + * off, but we need pt_regs->flags to have IF set. Second, if TS + * was set in usermode, it's still set, and we're singlestepping + * through this code. do_SYSENTER_32() will fix up IF. + */ + pushfq /* pt_regs->flags (except IF = 0) */ + pushq $__USER32_CS /* pt_regs->cs */ + pushq $0 /* pt_regs->ip = 0 (placeholder) */ +SYM_INNER_LABEL(entry_SYSENTER_compat_after_hwframe, SYM_L_GLOBAL) /* * User tracing code (ptrace or signal handlers) might assume that @@ -64,20 +83,6 @@ */ movl %eax, %eax - /* Construct struct pt_regs on stack */ - pushq $__USER32_DS /* pt_regs->ss */ - pushq %rbp /* pt_regs->sp (stashed in bp) */ - - /* - * Push flags. This is nasty. First, interrupts are currently - * off, but we need pt_regs->flags to have IF set. Second, even - * if TF was set when SYSENTER started, it's clear by now. We fix - * that later using TIF_SINGLESTEP. - */ - pushfq /* pt_regs->flags (except IF = 0) */ - orl $X86_EFLAGS_IF, (%rsp) /* Fix saved flags */ - pushq $__USER32_CS /* pt_regs->cs */ - pushq $0 /* pt_regs->ip = 0 (placeholder) */ pushq %rax /* pt_regs->orig_ax */ pushq %rdi /* pt_regs->di */ pushq %rsi /* pt_regs->si */ @@ -104,7 +109,13 @@ xorl %r14d, %r14d /* nospec r14 */ pushq $0 /* pt_regs->r15 = 0 */ xorl %r15d, %r15d /* nospec r15 */ + + UNWIND_HINT_REGS + cld + + IBRS_ENTER + UNTRAIN_RET /* * SYSENTER doesn't filter flags, so we need to clear NT and AC @@ -129,25 +140,19 @@ jnz .Lsysenter_fix_flags .Lsysenter_flags_fixed: - /* - * User mode is traced as though IRQs are on, and SYSENTER - * turned them off. - */ - TRACE_IRQS_OFF - movq %rsp, %rdi - call do_fast_syscall_32 + call do_SYSENTER_32 /* XEN PV guests always use IRET path */ - ALTERNATIVE "testl %eax, %eax; jz .Lsyscall_32_done", \ - "jmp .Lsyscall_32_done", X86_FEATURE_XENPV + ALTERNATIVE "testl %eax, %eax; jz swapgs_restore_regs_and_return_to_usermode", \ + "jmp swapgs_restore_regs_and_return_to_usermode", X86_FEATURE_XENPV jmp sysret32_from_system_call .Lsysenter_fix_flags: pushq $X86_EFLAGS_FIXED popfq jmp .Lsysenter_flags_fixed -GLOBAL(__end_entry_SYSENTER_compat) -ENDPROC(entry_SYSENTER_compat) +SYM_INNER_LABEL(__end_entry_SYSENTER_compat, SYM_L_GLOBAL) +SYM_CODE_END(entry_SYSENTER_compat) /* * 32-bit SYSCALL entry. @@ -196,7 +201,8 @@ * esp user stack * 0(%esp) arg6 */ -ENTRY(entry_SYSCALL_compat) +SYM_CODE_START(entry_SYSCALL_compat) + UNWIND_HINT_ENTRY /* Interrupts are off on entry. */ swapgs @@ -209,13 +215,15 @@ /* Switch to the kernel stack */ movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp +SYM_INNER_LABEL(entry_SYSCALL_compat_safe_stack, SYM_L_GLOBAL) + /* Construct struct pt_regs on stack */ pushq $__USER32_DS /* pt_regs->ss */ pushq %r8 /* pt_regs->sp */ pushq %r11 /* pt_regs->flags */ pushq $__USER32_CS /* pt_regs->cs */ pushq %rcx /* pt_regs->ip */ -GLOBAL(entry_SYSCALL_compat_after_hwframe) +SYM_INNER_LABEL(entry_SYSCALL_compat_after_hwframe, SYM_L_GLOBAL) movl %eax, %eax /* discard orig_ax high bits */ pushq %rax /* pt_regs->orig_ax */ pushq %rdi /* pt_regs->di */ @@ -247,21 +255,27 @@ pushq $0 /* pt_regs->r15 = 0 */ xorl %r15d, %r15d /* nospec r15 */ - /* - * User mode is traced as though IRQs are on, and SYSENTER - * turned them off. - */ - TRACE_IRQS_OFF + UNWIND_HINT_REGS + + IBRS_ENTER + UNTRAIN_RET movq %rsp, %rdi call do_fast_syscall_32 /* XEN PV guests always use IRET path */ - ALTERNATIVE "testl %eax, %eax; jz .Lsyscall_32_done", \ - "jmp .Lsyscall_32_done", X86_FEATURE_XENPV + ALTERNATIVE "testl %eax, %eax; jz swapgs_restore_regs_and_return_to_usermode", \ + "jmp swapgs_restore_regs_and_return_to_usermode", X86_FEATURE_XENPV /* Opportunistic SYSRET */ sysret32_from_system_call: - TRACE_IRQS_ON /* User mode traces as IRQs on. */ + /* + * We are not going to return to userspace from the trampoline + * stack. So let's erase the thread stack right now. + */ + STACKLEAK_ERASE + + IBRS_EXIT + movq RBX(%rsp), %rbx /* pt_regs->rbx */ movq RBP(%rsp), %rbp /* pt_regs->rbp */ movq EFLAGS(%rsp), %r11 /* pt_regs->flags (in r11) */ @@ -306,7 +320,7 @@ xorl %r10d, %r10d swapgs sysretl -END(entry_SYSCALL_compat) +SYM_CODE_END(entry_SYSCALL_compat) /* * 32-bit legacy system call entry. @@ -334,7 +348,8 @@ * edi arg5 * ebp arg6 */ -ENTRY(entry_INT80_compat) +SYM_CODE_START(entry_INT80_compat) + UNWIND_HINT_ENTRY /* * Interrupts are off on entry. */ @@ -356,8 +371,11 @@ /* Need to switch before accessing the thread stack. */ SWITCH_TO_KERNEL_CR3 scratch_reg=%rdi + /* In the Xen PV case we already run on the thread stack. */ - ALTERNATIVE "movq %rsp, %rdi", "jmp .Lint80_keep_stack", X86_FEATURE_XENPV + ALTERNATIVE "", "jmp .Lint80_keep_stack", X86_FEATURE_XENPV + + movq %rsp, %rdi movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp pushq 6*8(%rdi) /* regs->ss */ @@ -396,19 +414,15 @@ xorl %r14d, %r14d /* nospec r14 */ pushq %r15 /* pt_regs->r15 */ xorl %r15d, %r15d /* nospec r15 */ + + UNWIND_HINT_REGS + cld - /* - * User mode is traced as though IRQs are on, and the interrupt - * gate turned them off. - */ - TRACE_IRQS_OFF + IBRS_ENTER + UNTRAIN_RET movq %rsp, %rdi call do_int80_syscall_32 -.Lsyscall_32_done: - - /* Go back to user mode. */ - TRACE_IRQS_ON jmp swapgs_restore_regs_and_return_to_usermode -END(entry_INT80_compat) +SYM_CODE_END(entry_INT80_compat) -- Gitblit v1.6.2