Commit-ID: 7a59ed415f5b57469e22e41fc4188d5399e0b194 Gitweb: http://git.kernel.org/tip/7a59ed415f5b57469e22e41fc4188d5399e0b194 Author: Stefani Seibold <stef...@seibold.net> AuthorDate: Mon, 17 Mar 2014 23:22:09 +0100 Committer: H. Peter Anvin <h...@linux.intel.com> CommitDate: Tue, 18 Mar 2014 12:52:37 -0700
x86, vdso: Add 32 bit VDSO time support for 32 bit kernel 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. Reviewed-by: Andy Lutomirski <l...@amacapital.net> Signed-off-by: Stefani Seibold <stef...@seibold.net> Link: http://lkml.kernel.org/r/1395094933-14252-10-git-send-email-stef...@seibold.net Signed-off-by: H. Peter Anvin <h...@linux.intel.com> --- arch/x86/include/asm/vdso.h | 5 +++ arch/x86/include/asm/vdso32.h | 11 +++++ arch/x86/vdso/Makefile | 8 ++++ arch/x86/vdso/vclock_gettime.c | 76 +++++++++++++++++++++++++++++++---- arch/x86/vdso/vdso-layout.lds.S | 22 ++++++++++ arch/x86/vdso/vdso32-setup.c | 47 ++++++++++++++++++++-- arch/x86/vdso/vdso32/vclock_gettime.c | 9 +++++ arch/x86/vdso/vdso32/vdso32.lds.S | 11 +++++ 8 files changed, 178 insertions(+), 11 deletions(-) diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h index f8605e6..bde4359 100644 --- a/arch/x86/include/asm/vdso.h +++ b/arch/x86/include/asm/vdso.h @@ -2,6 +2,11 @@ #define _ASM_X86_VDSO_H #if defined CONFIG_X86_32 || defined CONFIG_COMPAT + +#include <asm/vdso32.h> + +extern const char VDSO32_PRELINK[]; + /* * Given a pointer to the vDSO image, find the pointer to VDSO32_name * as that symbol is defined in the vDSO sources or linker script. 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 7a3d13e..6cef7a1 100644 --- a/arch/x86/vdso/Makefile +++ b/arch/x86/vdso/Makefile @@ -146,8 +146,16 @@ 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 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32)) +KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -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..90bb5e8 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 <stef...@seibold.net> + * sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany + * * The code should have no internal unresolved relocations. * Check with readelf after changing. */ @@ -12,13 +15,11 @@ #define DISABLE_BRANCH_PROFILING #include <linux/kernel.h> -#include <linux/posix-timers.h> -#include <linux/time.h> +#include <uapi/linux/time.h> #include <linux/string.h> #include <asm/vsyscall.h> #include <asm/fixmap.h> #include <asm/vgtod.h> -#include <asm/timex.h> #include <asm/hpet.h> #include <asm/unistd.h> #include <asm/io.h> @@ -26,6 +27,12 @@ #define gtod (&VVAR(vsyscall_gtod_data)) +extern int __vdso_clock_gettime(clockid_t clock, struct timespec *ts); +extern int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz); +extern time_t __vdso_time(time_t *t); + +#ifndef BUILD_VDSO32 + static notrace cycle_t vread_hpet(void) { return readl((const void __iomem *)fix_to_virt(VSYSCALL_HPET) + HPET_COUNTER); @@ -118,6 +125,59 @@ static notrace cycle_t vread_pvclock(int *mode) } #endif +#else + +extern u8 hpet_page + __attribute__((visibility("hidden"))); + +#ifdef CONFIG_HPET_TIMER +static notrace cycle_t vread_hpet(void) +{ + return readl((const void __iomem *)(&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; @@ -131,7 +191,7 @@ notrace static cycle_t vread_tsc(void) * but no one has ever seen it happen. */ rdtsc_barrier(); - ret = (cycle_t)vget_cycles(); + ret = (cycle_t)__native_read_tsc(); last = gtod->clock.cycle_last; @@ -152,12 +212,14 @@ 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); @@ -189,7 +251,7 @@ notrace static int __always_inline do_realtime(struct timespec *ts) return mode; } -notrace static int do_monotonic(struct timespec *ts) +notrace static int __always_inline do_monotonic(struct timespec *ts) { unsigned long seq; u64 ns; @@ -284,7 +346,7 @@ 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 8c550c1..c6d0e1b 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 <asm/vdso32.h> + + .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 <asm/vvar.h> +#undef __VVAR_KERNEL_LDS +#undef EMIT_VVAR + } :text :vvar_sect +#endif . = 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 e0fc767..e10abdf 100644 --- a/arch/x86/vdso/vdso32-setup.c +++ b/arch/x86/vdso/vdso32-setup.c @@ -25,6 +25,9 @@ #include <asm/tlbflush.h> #include <asm/vdso.h> #include <asm/proto.h> +#include <asm/fixmap.h> +#include <asm/hpet.h> +#include <asm/vvar.h> #ifdef CONFIG_COMPAT_VDSO #define VDSO_DEFAULT 0 @@ -141,6 +144,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) struct mm_struct *mm = current->mm; unsigned long addr; int ret = 0; + struct vm_area_struct *vma; #ifdef CONFIG_X86_X32_ABI if (test_thread_flag(TIF_X32)) @@ -163,14 +167,49 @@ 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 = VDSO32_SYMBOL(addr, 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..ca65e42 --- /dev/null +++ b/arch/x86/vdso/vdso32/vclock_gettime.c @@ -0,0 +1,9 @@ +#define BUILD_VDSO32 + +#ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE +#undef CONFIG_OPTIMIZE_INLINING +#endif + +#undef CONFIG_X86_PPRO_FENCE + +#include "../vclock_gettime.c" diff --git a/arch/x86/vdso/vdso32/vdso32.lds.S b/arch/x86/vdso/vdso32/vdso32.lds.S index 90e7aa9..28c4607 100644 --- a/arch/x86/vdso/vdso32/vdso32.lds.S +++ b/arch/x86/vdso/vdso32/vdso32.lds.S @@ -8,6 +8,11 @@ * values visible using the asm-x86/vdso.h macros from the kernel proper. */ +#include <asm/page.h> + +#define BUILD_VDSO32 +#define VDSO_PRELINK 0 + #include "../vdso-layout.lds.S" /* The ELF entry point can be used to set the AT_SYSINFO value. */ @@ -23,6 +28,9 @@ VERSION __kernel_vsyscall; __kernel_sigreturn; __kernel_rt_sigreturn; + __vdso_clock_gettime; + __vdso_gettimeofday; + __vdso_time; local: *; }; } @@ -33,3 +41,6 @@ VERSION 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; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
