From: Roger Pau Monné Date: Tue, 2 Jun 2020 11:38:32 +0000 (+0200) Subject: x86/cpu: fix build with clang 3.5 X-Git-Tag: archive/raspbian/4.14.0+80-gd101b417b7-1+rpi1^2~63^2~120 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=51461114e2639596fce174fcdd2fab608883ab3e;p=xen.git x86/cpu: fix build with clang 3.5 Clang 3.5 complains with: common.c:794:24: error: statement expression not allowed at file scope i < ARRAY_SIZE(this_cpu(tss_page).ist_ssp); ++i ) ^ /build/xen/include/asm/percpu.h:14:7: note: expanded from macro 'this_cpu' (*RELOC_HIDE(&per_cpu__##var, get_cpu_info()->per_cpu_offset)) ^ /build/xen/include/xen/compiler.h:104:3: note: expanded from macro 'RELOC_HIDE' ({ unsigned long __ptr; \ ^ /build/xen/include/xen/lib.h:68:69: note: expanded from macro 'ARRAY_SIZE' #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]) + __must_be_array(x)) ^ /build/xen/include/xen/compiler.h:85:57: note: expanded from macro '__must_be_array' BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0]))) ^ /build/xen/include/xen/lib.h:39:57: note: expanded from macro 'BUILD_BUG_ON_ZERO' #define BUILD_BUG_ON_ZERO(cond) sizeof(struct { int:-!!(cond); }) ^ Workaround this by defining the tss_page as a local variable. Adjust other users of the per-cpu tss_page to also use the newly introduced local variable. No functional change expected. Signed-off-by: Roger Pau Monné Reviewed-by: Wei Liu Acked-by: Andrew Cooper Release-acked-by: Paul Durrant --- diff --git a/xen/arch/x86/cpu/common.c b/xen/arch/x86/cpu/common.c index 58f0876180..da74172776 100644 --- a/xen/arch/x86/cpu/common.c +++ b/xen/arch/x86/cpu/common.c @@ -738,9 +738,14 @@ void load_system_tables(void) unsigned int i, cpu = smp_processor_id(); unsigned long stack_bottom = get_stack_bottom(), stack_top = stack_bottom & ~(STACK_SIZE - 1); + /* + * NB: define tss_page as a local variable because clang 3.5 doesn't + * support using ARRAY_SIZE against per-cpu variables. + */ + struct tss_page *tss_page = &this_cpu(tss_page); /* The TSS may be live. Disuade any clever optimisations. */ - volatile struct tss64 *tss = &this_cpu(tss_page).tss; + volatile struct tss64 *tss = &tss_page->tss; seg_desc_t *gdt = this_cpu(gdt) - FIRST_RESERVED_GDT_ENTRY; @@ -783,15 +788,14 @@ void load_system_tables(void) * volatile qualifier. */ if (cpu_has_xen_shstk) { - volatile uint64_t *ist_ssp = this_cpu(tss_page).ist_ssp; + volatile uint64_t *ist_ssp = tss_page->ist_ssp; ist_ssp[0] = 0x8600111111111111ul; ist_ssp[IST_MCE] = stack_top + (IST_MCE * IST_SHSTK_SIZE) - 8; ist_ssp[IST_NMI] = stack_top + (IST_NMI * IST_SHSTK_SIZE) - 8; ist_ssp[IST_DB] = stack_top + (IST_DB * IST_SHSTK_SIZE) - 8; ist_ssp[IST_DF] = stack_top + (IST_DF * IST_SHSTK_SIZE) - 8; - for ( i = IST_DF + 1; - i < ARRAY_SIZE(this_cpu(tss_page).ist_ssp); ++i ) + for ( i = IST_DF + 1; i < ARRAY_SIZE(tss_page->ist_ssp); ++i ) ist_ssp[i] = 0x8600111111111111ul; wrmsrl(MSR_INTERRUPT_SSP_TABLE, (unsigned long)ist_ssp);