From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752562AbaBNIyX (ORCPT ); Fri, 14 Feb 2014 03:54:23 -0500 Received: from www84.your-server.de ([213.133.104.84]:34705 "EHLO www84.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751820AbaBNIwJ (ORCPT ); Fri, 14 Feb 2014 03:52:09 -0500 From: Stefani Seibold To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, x86@kernel.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, ak@linux.intel.com, aarcange@redhat.com, john.stultz@linaro.org, luto@amacapital.net, xemul@parallels.com, gorcunov@openvz.org, andriy.shevchenko@linux.intel.com Cc: Martin.Runge@rohde-schwarz.com, Andreas.Brief@rohde-schwarz.com, Stefani Seibold Subject: [PATCH v16 08/10] Add 32 bit VDSO time support for 32 bit kernel Date: Fri, 14 Feb 2014 09:52:42 +0100 Message-Id: <1392367964-32118-9-git-send-email-stefani@seibold.net> X-Mailer: git-send-email 1.8.5.4 In-Reply-To: <1392367964-32118-1-git-send-email-stefani@seibold.net> References: <1392367964-32118-1-git-send-email-stefani@seibold.net> X-Authenticated-Sender: stefani@seibold.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch add the time support for 32 bit a VDSO to a 32 bit kernel. For 32 bit programs running on a 32 bit kernel, the same mechanism is used as for 64 bit programs running on a 64 bit kernel. Signed-off-by: Stefani Seibold --- arch/x86/include/asm/vdso.h | 3 ++ arch/x86/include/asm/vdso32.h | 11 ++++++ arch/x86/vdso/Makefile | 7 ++++ arch/x86/vdso/vclock_gettime.c | 64 +++++++++++++++++++++++++++++++++-- arch/x86/vdso/vdso-layout.lds.S | 22 ++++++++++++ arch/x86/vdso/vdso32-setup.c | 53 +++++++++++++++++++++++++---- arch/x86/vdso/vdso32/vclock_gettime.c | 36 ++++++++++++++++++++ arch/x86/vdso/vdso32/vdso32.lds.S | 9 +++++ 8 files changed, 197 insertions(+), 8 deletions(-) create mode 100644 arch/x86/include/asm/vdso32.h create mode 100644 arch/x86/vdso/vdso32/vclock_gettime.c diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h index fddb53d..fe3cef9 100644 --- a/arch/x86/include/asm/vdso.h +++ b/arch/x86/include/asm/vdso.h @@ -2,6 +2,9 @@ #define _ASM_X86_VDSO_H #if defined CONFIG_X86_32 || defined CONFIG_COMPAT + +#include + extern const char VDSO32_PRELINK[]; /* diff --git a/arch/x86/include/asm/vdso32.h b/arch/x86/include/asm/vdso32.h new file mode 100644 index 0000000..7efb701 --- /dev/null +++ b/arch/x86/include/asm/vdso32.h @@ -0,0 +1,11 @@ +#ifndef _ASM_X86_VDSO32_H +#define _ASM_X86_VDSO32_H + +#define VDSO_BASE_PAGE 0 +#define VDSO_VVAR_PAGE 1 +#define VDSO_HPET_PAGE 2 +#define VDSO_PAGES 3 +#define VDSO_PREV_PAGES 2 +#define VDSO_OFFSET(x) ((x) * PAGE_SIZE) + +#endif diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile index fd14be1..1ff5b0a 100644 --- a/arch/x86/vdso/Makefile +++ b/arch/x86/vdso/Makefile @@ -145,8 +145,15 @@ KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS)) $(vdso32-images:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_32) $(vdso32-images:%=$(obj)/%.dbg): asflags-$(CONFIG_X86_64) += -m32 +KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS)) +KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32)) +KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32)) +KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=3 -freg-struct-return -fpic +$(vdso32-images:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_32) + $(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \ $(obj)/vdso32/vdso32.lds \ + $(obj)/vdso32/vclock_gettime.o \ $(obj)/vdso32/note.o \ $(obj)/vdso32/%.o $(call if_changed,vdso) diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c index 09dae4a..8f1ed88 100644 --- a/arch/x86/vdso/vclock_gettime.c +++ b/arch/x86/vdso/vclock_gettime.c @@ -4,6 +4,9 @@ * * Fast user context implementation of clock_gettime, gettimeofday, and time. * + * 32 Bit compat layer by Stefani Seibold + * sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany + * * The code should have no internal unresolved relocations. * Check with readelf after changing. */ @@ -26,6 +29,8 @@ #define gtod (&VVAR(vsyscall_gtod_data)) +#ifndef BUILD_VDSO32 + static notrace cycle_t vread_hpet(void) { return readl((const void __iomem *)fix_to_virt(VSYSCALL_HPET) + HPET_COUNTER); @@ -118,6 +123,59 @@ static notrace cycle_t vread_pvclock(int *mode) } #endif +#else + +u8 hpet_page + __attribute__((visibility("hidden"))); + +#ifdef CONFIG_HPET_TIMER +static notrace cycle_t vread_hpet(void) +{ + return readl(&hpet_page + HPET_COUNTER); +} +#endif + +notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) +{ + long ret; + + asm( + "mov %%ebx, %%edx \n" + "mov %2, %%ebx \n" + "call VDSO32_vsyscall \n" + "mov %%edx, %%ebx \n" + : "=a" (ret) + : "0" (__NR_clock_gettime), "g" (clock), "c" (ts) + : "memory", "edx"); + return ret; +} + +notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz) +{ + long ret; + + asm( + "mov %%ebx, %%edx \n" + "mov %2, %%ebx \n" + "call VDSO32_vsyscall \n" + "mov %%edx, %%ebx \n" + : "=a" (ret) + : "0" (__NR_gettimeofday), "g" (tv), "c" (tz) + : "memory", "edx"); + return ret; +} + +#ifdef CONFIG_PARAVIRT_CLOCK + +static notrace cycle_t vread_pvclock(int *mode) +{ + *mode = VCLOCK_NONE; + return 0; +} +#endif + +#endif + notrace static cycle_t vread_tsc(void) { cycle_t ret; @@ -152,12 +210,14 @@ notrace static cycle_t vread_tsc(void) notrace static inline u64 vgetsns(int *mode) { - long v; + u64 v; cycles_t cycles; if (gtod->clock.vclock_mode == VCLOCK_TSC) cycles = vread_tsc(); +#ifdef CONFIG_HPET_TIMER else if (gtod->clock.vclock_mode == VCLOCK_HPET) cycles = vread_hpet(); +#endif #ifdef CONFIG_PARAVIRT_CLOCK else if (gtod->clock.vclock_mode == VCLOCK_PVCLOCK) cycles = vread_pvclock(mode); @@ -284,7 +344,7 @@ int gettimeofday(struct timeval *, struct timezone *) */ notrace time_t __vdso_time(time_t *t) { - /* This is atomic on x86_64 so we don't need any locks. */ + /* This is atomic on x86 so we don't need any locks. */ time_t result = ACCESS_ONCE(gtod->wall_time_sec); if (t) diff --git a/arch/x86/vdso/vdso-layout.lds.S b/arch/x86/vdso/vdso-layout.lds.S index 634a2cf..1261437 100644 --- a/arch/x86/vdso/vdso-layout.lds.S +++ b/arch/x86/vdso/vdso-layout.lds.S @@ -6,6 +6,24 @@ SECTIONS { +#ifdef BUILD_VDSO32 +#include + + .hpet_sect : { + hpet_page = . - VDSO_OFFSET(VDSO_HPET_PAGE); + } :text :hpet_sect + + .vvar_sect : { + vvar = . - VDSO_OFFSET(VDSO_VVAR_PAGE); + + /* Place all vvars at the offsets in asm/vvar.h. */ +#define EMIT_VVAR(name, offset) vvar_ ## name = vvar + offset; +#define __VVAR_KERNEL_LDS +#include +#undef __VVAR_KERNEL_LDS +#undef EMIT_VVAR + } :text :vvar_sect +#endif . = VDSO_PRELINK + SIZEOF_HEADERS; .hash : { *(.hash) } :text @@ -61,4 +79,8 @@ PHDRS dynamic PT_DYNAMIC FLAGS(4); /* PF_R */ note PT_NOTE FLAGS(4); /* PF_R */ eh_frame_hdr PT_GNU_EH_FRAME; +#ifdef BUILD_VDSO32 + vvar_sect PT_NULL FLAGS(4); /* PF_R */ + hpet_sect PT_NULL FLAGS(4); /* PF_R */ +#endif } diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c index d6bfb87..9b57770 100644 --- a/arch/x86/vdso/vdso32-setup.c +++ b/arch/x86/vdso/vdso32-setup.c @@ -25,6 +25,9 @@ #include #include #include +#include +#include +#include enum { VDSO_DISABLED = 0, @@ -193,7 +196,7 @@ static __init void relocate_vdso(Elf32_Ehdr *ehdr) } } -static struct page *vdso32_pages[1]; +static struct page *vdso32_pages[VDSO_PAGES]; #ifdef CONFIG_X86_64 @@ -310,6 +313,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) unsigned long addr; int ret = 0; bool compat; + struct vm_area_struct *vma; #ifdef CONFIG_X86_X32_ABI if (test_thread_flag(TIF_X32)) @@ -330,11 +334,13 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) if (compat) addr = VDSO_HIGH_BASE; else { - addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0); + addr = get_unmapped_area(NULL, 0, VDSO_OFFSET(VDSO_PAGES), 0, 0); if (IS_ERR_VALUE(addr)) { ret = addr; goto up_fail; } + + addr += VDSO_OFFSET(VDSO_PREV_PAGES); } current->mm->context.vdso = (void *)addr; @@ -343,13 +349,48 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) /* * MAYWRITE to allow gdb to COW and set breakpoints */ - ret = install_special_mapping(mm, addr, PAGE_SIZE, - VM_READ|VM_EXEC| - VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, - vdso32_pages); + ret = install_special_mapping(mm, + addr, + VDSO_OFFSET(VDSO_PAGES - VDSO_PREV_PAGES), + VM_READ|VM_EXEC| + VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, + vdso32_pages); if (ret) goto up_fail; + + vma = _install_special_mapping(mm, + addr - VDSO_OFFSET(VDSO_PREV_PAGES), + VDSO_OFFSET(VDSO_PREV_PAGES), + VM_READ, + NULL); + + if (IS_ERR(vma)) { + ret = PTR_ERR(vma); + goto up_fail; + } + + ret = remap_pfn_range(vma, + addr - VDSO_OFFSET(VDSO_VVAR_PAGE), + __pa_symbol(&__vvar_page) >> PAGE_SHIFT, + PAGE_SIZE, + PAGE_READONLY); + + if (ret) + goto up_fail; + +#ifdef CONFIG_HPET_TIMER + if (hpet_address) { + ret = io_remap_pfn_range(vma, + addr - VDSO_OFFSET(VDSO_HPET_PAGE), + hpet_address >> PAGE_SHIFT, + PAGE_SIZE, + pgprot_noncached(PAGE_READONLY)); + + if (ret) + goto up_fail; + } +#endif } current_thread_info()->sysenter_return = diff --git a/arch/x86/vdso/vdso32/vclock_gettime.c b/arch/x86/vdso/vdso32/vclock_gettime.c new file mode 100644 index 0000000..ffdbdb1 --- /dev/null +++ b/arch/x86/vdso/vdso32/vclock_gettime.c @@ -0,0 +1,36 @@ +#define BUILD_VDSO32 + +#ifdef CONFIG_X86_64 + +/* + * Due the -m32 compilation, there will be a lot of + * "warning: integer constant is too large for 'unsigned long' type", + * because an unsigned long is only 32 bit. + */ + +/* + * Prevents the include of arch/x86/include/asm/page.h, which will generate + * a lot of warnings. + */ +#define _ASM_X86_PAGE_H + +/* + * The unneeded inline function phys_to_virt() in arch/x86/include/asm/io.h + * depends on the __va(), which comes from arch/x86/include/asm/page.h. + * So add a dummy for this. + * + * It is save, since this functions not used in arch/x86/vdso/vclock_gettime.c + */ +#define __va(x) 0 + +/* + * The define of CONFIG_ILLEGAL_POINTER_VALUE is also to prevent the + * "warning: integer constant is too large..." + */ +#undef CONFIG_ILLEGAL_POINTER_VALUE +#define CONFIG_ILLEGAL_POINTER_VALUE 0 + +#endif + +#include "../vclock_gettime.c" + diff --git a/arch/x86/vdso/vdso32/vdso32.lds.S b/arch/x86/vdso/vdso32/vdso32.lds.S index 976124b..bc8bf6d 100644 --- a/arch/x86/vdso/vdso32/vdso32.lds.S +++ b/arch/x86/vdso/vdso32/vdso32.lds.S @@ -8,6 +8,9 @@ * values visible using the asm-x86/vdso.h macros from the kernel proper. */ +#include + +#define BUILD_VDSO32 #define VDSO_PRELINK 0 #include "../vdso-layout.lds.S" @@ -24,6 +27,9 @@ VERSION __kernel_vsyscall; __kernel_sigreturn; __kernel_rt_sigreturn; + __vdso_clock_gettime; + __vdso_gettimeofday; + __vdso_time; local: *; }; } @@ -35,3 +41,6 @@ VDSO32_PRELINK = VDSO_PRELINK; VDSO32_vsyscall = __kernel_vsyscall; VDSO32_sigreturn = __kernel_sigreturn; VDSO32_rt_sigreturn = __kernel_rt_sigreturn; +VDSO32_clock_gettime = clock_gettime; +VDSO32_gettimeofday = gettimeofday; +VDSO32_time = time; -- 1.8.5.4