From 3207426925d2b4da390be8068df1d1c2b36e5918 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 14 Apr 2019 17:59:55 +0200 Subject: [PATCH] x86/exceptions: Disconnect IST index and stack order The entry order of the TSS.IST array and the order of the stack storage/mapping are not required to be the same. With the upcoming split of the debug stack this is going to fall apart as the number of TSS.IST array entries stays the same while the actual stacks are increasing. Make them separate so that code like dumpstack can just utilize the mapping order. The IST index is solely required for the actual TSS.IST array initialization. Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Cc: Andy Lutomirski Cc: Baoquan He Cc: "Chang S. Bae" Cc: Dominik Brodowski Cc: Dou Liyang Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jann Horn Cc: Josh Poimboeuf Cc: Kees Cook Cc: "Kirill A. Shutemov" Cc: Konrad Rzeszutek Wilk Cc: Nicolai Stange Cc: Peter Zijlstra Cc: Qian Cai Cc: Sean Christopherson Cc: x86-ml Link: https://lkml.kernel.org/r/20190414160145.241588113@linutronix.de --- arch/x86/entry/entry_64.S | 2 +- arch/x86/include/asm/cpu_entry_area.h | 11 +++++++++++ arch/x86/include/asm/page_64_types.h | 9 ++++----- arch/x86/include/asm/stacktrace.h | 2 ++ arch/x86/kernel/cpu/common.c | 10 +++++----- arch/x86/kernel/idt.c | 8 ++++---- 6 files changed, 27 insertions(+), 15 deletions(-) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index fd0a50452cb3..5c0348504a4b 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1129,7 +1129,7 @@ apicinterrupt3 HYPERV_STIMER0_VECTOR \ hv_stimer0_callback_vector hv_stimer0_vector_handler #endif /* CONFIG_HYPERV */ -idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=ESTACK_DB +idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=IST_INDEX_DB idtentry int3 do_int3 has_error_code=0 idtentry stack_segment do_stack_segment has_error_code=1 diff --git a/arch/x86/include/asm/cpu_entry_area.h b/arch/x86/include/asm/cpu_entry_area.h index 9b406f067ecf..310eeb62d418 100644 --- a/arch/x86/include/asm/cpu_entry_area.h +++ b/arch/x86/include/asm/cpu_entry_area.h @@ -35,6 +35,17 @@ struct cea_exception_stacks { ESTACKS_MEMBERS(0) }; +/* + * The exception stack ordering in [cea_]exception_stacks + */ +enum exception_stack_ordering { + ESTACK_DF, + ESTACK_NMI, + ESTACK_DB, + ESTACK_MCE, + N_EXCEPTION_STACKS +}; + #define CEA_ESTACK_SIZE(st) \ sizeof(((struct cea_exception_stacks *)0)->st## _stack) diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h index 6ab2c54c1bf9..056de887b220 100644 --- a/arch/x86/include/asm/page_64_types.h +++ b/arch/x86/include/asm/page_64_types.h @@ -27,11 +27,10 @@ /* * The index for the tss.ist[] array. The hardware limit is 7 entries. */ -#define ESTACK_DF 0 -#define ESTACK_NMI 1 -#define ESTACK_DB 2 -#define ESTACK_MCE 3 -#define N_EXCEPTION_STACKS 4 +#define IST_INDEX_DF 0 +#define IST_INDEX_NMI 1 +#define IST_INDEX_DB 2 +#define IST_INDEX_MCE 3 /* * Set __PAGE_OFFSET to the most negative possible address + diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h index f335aad404a4..d6d758a187b6 100644 --- a/arch/x86/include/asm/stacktrace.h +++ b/arch/x86/include/asm/stacktrace.h @@ -9,6 +9,8 @@ #include #include + +#include #include enum stack_type { diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 8243f198fb7f..143aceaf9a9a 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1731,11 +1731,11 @@ void cpu_init(void) * set up and load the per-CPU TSS */ if (!t->x86_tss.ist[0]) { - t->x86_tss.ist[ESTACK_DF] = __this_cpu_ist_top_va(DF); - t->x86_tss.ist[ESTACK_NMI] = __this_cpu_ist_top_va(NMI); - t->x86_tss.ist[ESTACK_DB] = __this_cpu_ist_top_va(DB); - t->x86_tss.ist[ESTACK_MCE] = __this_cpu_ist_top_va(MCE); - per_cpu(debug_stack_addr, cpu) = t->x86_tss.ist[ESTACK_DB]; + t->x86_tss.ist[IST_INDEX_DF] = __this_cpu_ist_top_va(DF); + t->x86_tss.ist[IST_INDEX_NMI] = __this_cpu_ist_top_va(NMI); + t->x86_tss.ist[IST_INDEX_DB] = __this_cpu_ist_top_va(DB); + t->x86_tss.ist[IST_INDEX_MCE] = __this_cpu_ist_top_va(MCE); + per_cpu(debug_stack_addr, cpu) = t->x86_tss.ist[IST_INDEX_DB]; } t->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET; diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c index 2188f734ec61..6d8917875f44 100644 --- a/arch/x86/kernel/idt.c +++ b/arch/x86/kernel/idt.c @@ -183,11 +183,11 @@ gate_desc debug_idt_table[IDT_ENTRIES] __page_aligned_bss; * cpu_init() when the TSS has been initialized. */ static const __initconst struct idt_data ist_idts[] = { - ISTG(X86_TRAP_DB, debug, ESTACK_DB), - ISTG(X86_TRAP_NMI, nmi, ESTACK_NMI), - ISTG(X86_TRAP_DF, double_fault, ESTACK_DF), + ISTG(X86_TRAP_DB, debug, IST_INDEX_DB), + ISTG(X86_TRAP_NMI, nmi, IST_INDEX_NMI), + ISTG(X86_TRAP_DF, double_fault, IST_INDEX_DF), #ifdef CONFIG_X86_MCE - ISTG(X86_TRAP_MC, &machine_check, ESTACK_MCE), + ISTG(X86_TRAP_MC, &machine_check, IST_INDEX_MCE), #endif }; -- 2.30.2