4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andy Lutomirski <luto@xxxxxxxxxx> commit 0f9a48100fba3f189724ae88a450c2261bf91c80 upstream. The existing code was a mess, mainly because C arrays are nasty. Turn SYSENTER_stack into a struct, add a helper to find it, and do all the obvious cleanups this enables. Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Reviewed-by: Borislav Petkov <bpetkov@xxxxxxx> Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Brian Gerst <brgerst@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: David Laight <David.Laight@xxxxxxxxxx> Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx> Cc: Eduardo Valentin <eduval@xxxxxxxxxx> Cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Cc: Juergen Gross <jgross@xxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Cc: aliguori@xxxxxxxxxx Cc: daniel.gruss@xxxxxxxxxxxxxx Cc: hughd@xxxxxxxxxx Cc: keescook@xxxxxxxxxx Link: https://lkml.kernel.org/r/20171204150606.653244723@xxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/entry/entry_32.S | 4 ++-- arch/x86/entry/entry_64.S | 2 +- arch/x86/include/asm/fixmap.h | 5 +++++ arch/x86/include/asm/processor.h | 6 +++++- arch/x86/kernel/asm-offsets.c | 6 ++---- arch/x86/kernel/cpu/common.c | 14 +++----------- arch/x86/kernel/dumpstack.c | 7 +++---- 7 files changed, 21 insertions(+), 23 deletions(-) --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -942,7 +942,7 @@ ENTRY(debug) /* Are we currently on the SYSENTER stack? */ movl PER_CPU_VAR(cpu_entry_area), %ecx - addl $CPU_ENTRY_AREA_tss + CPU_TSS_SYSENTER_stack + SIZEOF_SYSENTER_stack, %ecx + addl $CPU_ENTRY_AREA_tss + TSS_STRUCT_SYSENTER_stack + SIZEOF_SYSENTER_stack, %ecx subl %eax, %ecx /* ecx = (end of SYSENTER_stack) - esp */ cmpl $SIZEOF_SYSENTER_stack, %ecx jb .Ldebug_from_sysenter_stack @@ -986,7 +986,7 @@ ENTRY(nmi) /* Are we currently on the SYSENTER stack? */ movl PER_CPU_VAR(cpu_entry_area), %ecx - addl $CPU_ENTRY_AREA_tss + CPU_TSS_SYSENTER_stack + SIZEOF_SYSENTER_stack, %ecx + addl $CPU_ENTRY_AREA_tss + TSS_STRUCT_SYSENTER_stack + SIZEOF_SYSENTER_stack, %ecx subl %eax, %ecx /* ecx = (end of SYSENTER_stack) - esp */ cmpl $SIZEOF_SYSENTER_stack, %ecx jb .Lnmi_from_sysenter_stack --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -154,7 +154,7 @@ END(native_usergs_sysret64) _entry_trampoline - CPU_ENTRY_AREA_entry_trampoline(%rip) /* The top word of the SYSENTER stack is hot and is usable as scratch space. */ -#define RSP_SCRATCH CPU_ENTRY_AREA_tss + CPU_TSS_SYSENTER_stack + \ +#define RSP_SCRATCH CPU_ENTRY_AREA_tss + TSS_STRUCT_SYSENTER_stack + \ SIZEOF_SYSENTER_stack - 8 + CPU_ENTRY_AREA ENTRY(entry_SYSCALL_64_trampoline) --- a/arch/x86/include/asm/fixmap.h +++ b/arch/x86/include/asm/fixmap.h @@ -245,5 +245,10 @@ static inline struct cpu_entry_area *get return (struct cpu_entry_area *)__fix_to_virt(__get_cpu_entry_area_page_index(cpu, 0)); } +static inline struct SYSENTER_stack *cpu_SYSENTER_stack(int cpu) +{ + return &get_cpu_entry_area(cpu)->tss.SYSENTER_stack; +} + #endif /* !__ASSEMBLY__ */ #endif /* _ASM_X86_FIXMAP_H */ --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -336,12 +336,16 @@ struct x86_hw_tss { #define IO_BITMAP_OFFSET (offsetof(struct tss_struct, io_bitmap) - offsetof(struct tss_struct, x86_tss)) #define INVALID_IO_BITMAP_OFFSET 0x8000 +struct SYSENTER_stack { + unsigned long words[64]; +}; + struct tss_struct { /* * Space for the temporary SYSENTER stack, used for SYSENTER * and the entry trampoline as well. */ - unsigned long SYSENTER_stack[64]; + struct SYSENTER_stack SYSENTER_stack; /* * The fixed hardware portion. This must not cross a page boundary --- a/arch/x86/kernel/asm-offsets.c +++ b/arch/x86/kernel/asm-offsets.c @@ -94,10 +94,8 @@ void common(void) { BLANK(); DEFINE(PTREGS_SIZE, sizeof(struct pt_regs)); - /* Offset from cpu_tss to SYSENTER_stack */ - OFFSET(CPU_TSS_SYSENTER_stack, tss_struct, SYSENTER_stack); - /* Size of SYSENTER_stack */ - DEFINE(SIZEOF_SYSENTER_stack, sizeof(((struct tss_struct *)0)->SYSENTER_stack)); + OFFSET(TSS_STRUCT_SYSENTER_stack, tss_struct, SYSENTER_stack); + DEFINE(SIZEOF_SYSENTER_stack, sizeof(struct SYSENTER_stack)); /* Layout info for cpu_entry_area */ OFFSET(CPU_ENTRY_AREA_tss, cpu_entry_area, tss); --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1314,12 +1314,7 @@ void enable_sep_cpu(void) tss->x86_tss.ss1 = __KERNEL_CS; wrmsr(MSR_IA32_SYSENTER_CS, tss->x86_tss.ss1, 0); - - wrmsr(MSR_IA32_SYSENTER_ESP, - (unsigned long)&get_cpu_entry_area(cpu)->tss + - offsetofend(struct tss_struct, SYSENTER_stack), - 0); - + wrmsr(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_SYSENTER_stack(cpu) + 1), 0); wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long)entry_SYSENTER_32, 0); put_cpu(); @@ -1436,9 +1431,7 @@ void syscall_init(void) * AMD doesn't allow SYSENTER in long mode (either 32- or 64-bit). */ wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS); - wrmsrl_safe(MSR_IA32_SYSENTER_ESP, - (unsigned long)&get_cpu_entry_area(cpu)->tss + - offsetofend(struct tss_struct, SYSENTER_stack)); + wrmsrl_safe(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_SYSENTER_stack(cpu) + 1)); wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)entry_SYSENTER_compat); #else wrmsrl(MSR_CSTAR, (unsigned long)ignore_sysret); @@ -1653,8 +1646,7 @@ void cpu_init(void) */ set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss); load_TR_desc(); - load_sp0((unsigned long)&get_cpu_entry_area(cpu)->tss + - offsetofend(struct tss_struct, SYSENTER_stack)); + load_sp0((unsigned long)(cpu_SYSENTER_stack(cpu) + 1)); load_mm_ldt(&init_mm); --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -45,11 +45,10 @@ bool in_task_stack(unsigned long *stack, bool in_sysenter_stack(unsigned long *stack, struct stack_info *info) { - int cpu = smp_processor_id(); - struct tss_struct *tss = &get_cpu_entry_area(cpu)->tss; + struct SYSENTER_stack *ss = cpu_SYSENTER_stack(smp_processor_id()); - void *begin = &tss->SYSENTER_stack; - void *end = (void *)&tss->SYSENTER_stack + sizeof(tss->SYSENTER_stack); + void *begin = ss; + void *end = ss + 1; if ((void *)stack < begin || (void *)stack >= end) return false;