diff options
| -rw-r--r-- | arch/x86/entry/entry_64_compat.S | 13 | ||||
| -rw-r--r-- | arch/x86/include/asm/unwind.h | 17 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/dumpstack.c | 31 | ||||
| -rw-r--r-- | arch/x86/kernel/process.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/stacktrace.c | 2 | ||||
| -rw-r--r-- | arch/x86/mm/pti.c | 3 | ||||
| -rw-r--r-- | security/Kconfig | 1 |
8 files changed, 48 insertions, 25 deletions
diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S index 40f17009ec20..98d5358e4041 100644 --- a/arch/x86/entry/entry_64_compat.S +++ b/arch/x86/entry/entry_64_compat.S @@ -190,8 +190,13 @@ ENTRY(entry_SYSCALL_compat) /* Interrupts are off on entry. */ swapgs - /* Stash user ESP and switch to the kernel stack. */ + /* Stash user ESP */ movl %esp, %r8d + + /* Use %rsp as scratch reg. User ESP is stashed in r8 */ + SWITCH_TO_KERNEL_CR3 scratch_reg=%rsp + + /* Switch to the kernel stack */ movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp /* Construct struct pt_regs on stack */ @@ -220,12 +225,6 @@ GLOBAL(entry_SYSCALL_compat_after_hwframe) pushq $0 /* pt_regs->r15 = 0 */ /* - * We just saved %rdi so it is safe to clobber. It is not - * preserved during the C calls inside TRACE_IRQS_OFF anyway. - */ - SWITCH_TO_KERNEL_CR3 scratch_reg=%rdi - - /* * User mode is traced as though IRQs are on, and SYSENTER * turned them off. */ diff --git a/arch/x86/include/asm/unwind.h b/arch/x86/include/asm/unwind.h index c1688c2d0a12..1f86e1b0a5cd 100644 --- a/arch/x86/include/asm/unwind.h +++ b/arch/x86/include/asm/unwind.h @@ -56,18 +56,27 @@ void unwind_start(struct unwind_state *state, struct task_struct *task, #if defined(CONFIG_UNWINDER_ORC) || defined(CONFIG_UNWINDER_FRAME_POINTER) /* - * WARNING: The entire pt_regs may not be safe to dereference. In some cases, - * only the iret frame registers are accessible. Use with caution! + * If 'partial' returns true, only the iret frame registers are valid. */ -static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state) +static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state, + bool *partial) { if (unwind_done(state)) return NULL; + if (partial) { +#ifdef CONFIG_UNWINDER_ORC + *partial = !state->full_regs; +#else + *partial = false; +#endif + } + return state->regs; } #else -static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state) +static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state, + bool *partial) { return NULL; } diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index c47de4ebf63a..7d9e3b06209b 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -923,8 +923,8 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) setup_force_cpu_cap(X86_FEATURE_ALWAYS); - /* Assume for now that ALL x86 CPUs are insecure */ - setup_force_cpu_bug(X86_BUG_CPU_INSECURE); + if (c->x86_vendor != X86_VENDOR_AMD) + setup_force_cpu_bug(X86_BUG_CPU_INSECURE); fpu__init_system(c); diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index 5fa110699ed2..afbecff161d1 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -76,12 +76,23 @@ void show_iret_regs(struct pt_regs *regs) regs->sp, regs->flags); } -static void show_regs_safe(struct stack_info *info, struct pt_regs *regs) +static void show_regs_if_on_stack(struct stack_info *info, struct pt_regs *regs, + bool partial) { - if (on_stack(info, regs, sizeof(*regs))) + /* + * These on_stack() checks aren't strictly necessary: the unwind code + * has already validated the 'regs' pointer. The checks are done for + * ordering reasons: if the registers are on the next stack, we don't + * want to print them out yet. Otherwise they'll be shown as part of + * the wrong stack. Later, when show_trace_log_lvl() switches to the + * next stack, this function will be called again with the same regs so + * they can be printed in the right context. + */ + if (!partial && on_stack(info, regs, sizeof(*regs))) { __show_regs(regs, 0); - else if (on_stack(info, (void *)regs + IRET_FRAME_OFFSET, - IRET_FRAME_SIZE)) { + + } else if (partial && on_stack(info, (void *)regs + IRET_FRAME_OFFSET, + IRET_FRAME_SIZE)) { /* * When an interrupt or exception occurs in entry code, the * full pt_regs might not have been saved yet. In that case @@ -98,11 +109,13 @@ void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, struct stack_info stack_info = {0}; unsigned long visit_mask = 0; int graph_idx = 0; + bool partial; printk("%sCall Trace:\n", log_lvl); unwind_start(&state, task, regs, stack); stack = stack ? : get_stack_pointer(task, regs); + regs = unwind_get_entry_regs(&state, &partial); /* * Iterate through the stacks, starting with the current stack pointer. @@ -120,7 +133,7 @@ void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, * - hardirq stack * - entry stack */ - for (regs = NULL; stack; stack = PTR_ALIGN(stack_info.next_sp, sizeof(long))) { + for ( ; stack; stack = PTR_ALIGN(stack_info.next_sp, sizeof(long))) { const char *stack_name; if (get_stack_info(stack, task, &stack_info, &visit_mask)) { @@ -140,7 +153,7 @@ void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, printk("%s <%s>\n", log_lvl, stack_name); if (regs) - show_regs_safe(&stack_info, regs); + show_regs_if_on_stack(&stack_info, regs, partial); /* * Scan the stack, printing any text addresses we find. At the @@ -164,7 +177,7 @@ void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, /* * Don't print regs->ip again if it was already printed - * by show_regs_safe() below. + * by show_regs_if_on_stack(). */ if (regs && stack == ®s->ip) goto next; @@ -199,9 +212,9 @@ next: unwind_next_frame(&state); /* if the frame has entry regs, print them */ - regs = unwind_get_entry_regs(&state); + regs = unwind_get_entry_regs(&state, &partial); if (regs) - show_regs_safe(&stack_info, regs); + show_regs_if_on_stack(&stack_info, regs, partial); } if (stack_name) diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index aed9d94bd46f..832a6acd730f 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -47,7 +47,7 @@ * section. Since TSS's are completely CPU-local, we want them * on exact cacheline boundaries, to eliminate cacheline ping-pong. */ -__visible DEFINE_PER_CPU_SHARED_ALIGNED(struct tss_struct, cpu_tss_rw) = { +__visible DEFINE_PER_CPU_PAGE_ALIGNED(struct tss_struct, cpu_tss_rw) = { .x86_tss = { /* * .sp0 is only used when entering ring 0 from a lower diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c index 20161ef53537..093f2ea5dd56 100644 --- a/arch/x86/kernel/stacktrace.c +++ b/arch/x86/kernel/stacktrace.c @@ -102,7 +102,7 @@ __save_stack_trace_reliable(struct stack_trace *trace, for (unwind_start(&state, task, NULL, NULL); !unwind_done(&state); unwind_next_frame(&state)) { - regs = unwind_get_entry_regs(&state); + regs = unwind_get_entry_regs(&state, NULL); if (regs) { /* * Kernel mode registers on the stack indicate an diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c index bce8aea65606..2da28ba97508 100644 --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -367,7 +367,8 @@ static void __init pti_setup_espfix64(void) static void __init pti_clone_entry_text(void) { pti_clone_pmds((unsigned long) __entry_text_start, - (unsigned long) __irqentry_text_end, _PAGE_RW); + (unsigned long) __irqentry_text_end, + _PAGE_RW | _PAGE_GLOBAL); } /* diff --git a/security/Kconfig b/security/Kconfig index a623d13bf288..3d4debd0257e 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -56,6 +56,7 @@ config SECURITY_NETWORK config PAGE_TABLE_ISOLATION bool "Remove the kernel mapping in user mode" + default y depends on X86_64 && !UML help This feature reduces the number of hardware side channels by |