From cc456c4e7cac3837a86aaa7ca3cb9f488d44d196 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Wed, 1 May 2013 21:53:30 -0400 Subject: x86, gdt, hibernate: Store/load GDT for hibernate path. The git commite7a5cd063c7b4c58417f674821d63f5eb6747e37 ("x86-64, gdt: Store/load GDT for ACPI S3 or hibernate/resume path is not needed.") assumes that for the hibernate path the booting kernel and the resuming kernel MUST be the same. That is certainly the case for a 32-bit kernel (see check_image_kernel and CONFIG_ARCH_HIBERNATION_HEADER config option). However for 64-bit kernels it is OK to have a different kernel version (and size of the image) of the booting and resuming kernels. Hence the above mentioned git commit introduces an regression. This patch fixes it by introducing a 'struct desc_ptr gdt_desc' back in the 'struct saved_context'. However instead of having in the 'save_processor_state' and 'restore_processor_state' the store/load_gdt calls, we are only saving the GDT in the save_processor_state. For the restore path the lgdt operation is done in hibernate_asm_[32|64].S in the 'restore_registers' path. The apt reader of this description will recognize that only 64-bit kernels need this treatment, not 32-bit. This patch adds the logic in the 32-bit path to be more similar to 64-bit so that in the future the unification process can take advantage of this. [ hpa: this also reverts an inadvertent on-disk format change ] Suggested-by: "H. Peter Anvin" Acked-by: "Rafael J. Wysocki" Signed-off-by: Konrad Rzeszutek Wilk Link: http://lkml.kernel.org/r/1367459610-9656-2-git-send-email-konrad.wilk@oracle.com Signed-off-by: H. Peter Anvin diff --git a/arch/x86/include/asm/suspend_32.h b/arch/x86/include/asm/suspend_32.h index f6064b7..552d6c9 100644 --- a/arch/x86/include/asm/suspend_32.h +++ b/arch/x86/include/asm/suspend_32.h @@ -15,6 +15,7 @@ struct saved_context { unsigned long cr0, cr2, cr3, cr4; u64 misc_enable; bool misc_enable_saved; + struct desc_ptr gdt_desc; struct desc_ptr idt; u16 ldt; u16 tss; diff --git a/arch/x86/include/asm/suspend_64.h b/arch/x86/include/asm/suspend_64.h index 97b84e0..bc62328 100644 --- a/arch/x86/include/asm/suspend_64.h +++ b/arch/x86/include/asm/suspend_64.h @@ -25,6 +25,8 @@ struct saved_context { u64 misc_enable; bool misc_enable_saved; unsigned long efer; + u16 gdt_pad; /* Unused */ + struct desc_ptr gdt_desc; u16 idt_pad; u16 idt_limit; unsigned long idt_base; diff --git a/arch/x86/kernel/asm-offsets_32.c b/arch/x86/kernel/asm-offsets_32.c index 85d98ab..0ef4bba 100644 --- a/arch/x86/kernel/asm-offsets_32.c +++ b/arch/x86/kernel/asm-offsets_32.c @@ -60,6 +60,9 @@ void foo(void) OFFSET(IA32_RT_SIGFRAME_sigcontext, rt_sigframe, uc.uc_mcontext); BLANK(); + OFFSET(saved_context_gdt_desc, saved_context, gdt_desc); + BLANK(); + /* Offset from the sysenter stack to tss.sp0 */ DEFINE(TSS_sysenter_sp0, offsetof(struct tss_struct, x86_tss.sp0) - sizeof(struct tss_struct)); diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c index 1b4754f..e7c798b 100644 --- a/arch/x86/kernel/asm-offsets_64.c +++ b/arch/x86/kernel/asm-offsets_64.c @@ -73,6 +73,7 @@ int main(void) ENTRY(cr3); ENTRY(cr4); ENTRY(cr8); + ENTRY(gdt_desc); BLANK(); #undef ENTRY diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c index 6d6e907..1cf5b30 100644 --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -25,16 +25,12 @@ #include #ifdef CONFIG_X86_32 -static struct saved_context saved_context; - unsigned long saved_context_ebx; unsigned long saved_context_esp, saved_context_ebp; unsigned long saved_context_esi, saved_context_edi; unsigned long saved_context_eflags; -#else -/* CONFIG_X86_64 */ -struct saved_context saved_context; #endif +struct saved_context saved_context; /** * __save_processor_state - save CPU registers before creating a @@ -67,6 +63,15 @@ static void __save_processor_state(struct saved_context *ctxt) /* CONFIG_X86_64 */ store_idt((struct desc_ptr *)&ctxt->idt_limit); #endif + /* + * We save it here, but restore it only in the hibernate case. + * For ACPI S3 resume, this is loaded via 'early_gdt_desc' in 64-bit + * mode in "secondary_startup_64". In 32-bit mode it is done via + * 'pmode_gdt' in wakeup_start. + */ + ctxt->gdt_desc.size = GDT_SIZE - 1; + ctxt->gdt_desc.address = (unsigned long)get_cpu_gdt_table(smp_processor_id()); + store_tr(ctxt->tr); /* XMM0..XMM15 should be handled by kernel_fpu_begin(). */ diff --git a/arch/x86/power/hibernate_asm_32.S b/arch/x86/power/hibernate_asm_32.S index ad47dae..1d0fa0e 100644 --- a/arch/x86/power/hibernate_asm_32.S +++ b/arch/x86/power/hibernate_asm_32.S @@ -75,6 +75,10 @@ done: pushl saved_context_eflags popfl + /* Saved in save_processor_state. */ + movl $saved_context, %eax + lgdt saved_context_gdt_desc(%eax) + xorl %eax, %eax ret diff --git a/arch/x86/power/hibernate_asm_64.S b/arch/x86/power/hibernate_asm_64.S index 9356547..3c4469a 100644 --- a/arch/x86/power/hibernate_asm_64.S +++ b/arch/x86/power/hibernate_asm_64.S @@ -139,6 +139,9 @@ ENTRY(restore_registers) pushq pt_regs_flags(%rax) popfq + /* Saved in save_processor_state. */ + lgdt saved_context_gdt_desc(%rax) + xorq %rax, %rax /* tell the hibernation core that we've just restored the memory */ -- cgit v0.10.2 From 78d77df71510a96e042de7ba6dbd7998103642cb Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Thu, 2 May 2013 10:33:46 -0700 Subject: x86-64, init: Do not set NX bits on non-NX capable hardware MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit During early init, we would incorrectly set the NX bit even if the NX feature was not supported. Instead, only set this bit if NX is actually available and enabled. We already do very early detection of the NX bit to enable it in EFER, this simply extends this detection to the early page table mask. Reported-by: Fernando Luis Vázquez Cao Signed-off-by: H. Peter Anvin Link: http://lkml.kernel.org/r/1367476850.5660.2.camel@nexus Cc: v3.9 diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 101ac1a9..dab95a8 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -34,6 +34,7 @@ extern pgd_t early_level4_pgt[PTRS_PER_PGD]; extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD]; static unsigned int __initdata next_early_pgt = 2; +pmdval_t __initdata early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX); /* Wipe all early page tables except for the kernel symbol map */ static void __init reset_early_page_tables(void) @@ -99,7 +100,7 @@ again: pmd_p[i] = 0; *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; } - pmd = (physaddr & PMD_MASK) + (__PAGE_KERNEL_LARGE & ~_PAGE_GLOBAL); + pmd = (physaddr & PMD_MASK) + early_pmd_flags; pmd_p[pmd_index(address)] = pmd; return 0; diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 6859e96..08f7e80 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -200,6 +200,7 @@ ENTRY(secondary_startup_64) btl $20,%edi /* No Execute supported? */ jnc 1f btsl $_EFER_NX, %eax + btsq $_PAGE_BIT_NX,early_pmd_flags(%rip) 1: wrmsr /* Make changes effective */ /* Setup cr0 */ -- cgit v0.10.2