diff options
author | Linus Torvalds | 2014-04-02 12:26:43 -0700 |
---|---|---|
committer | Linus Torvalds | 2014-04-02 12:26:43 -0700 |
commit | c6f21243ce1e8d81ad8361da4d2eaa5947b667c4 (patch) | |
tree | 5157ca1de2e7a5371575fff92ce23f0d09e3e7ea /arch/x86/vdso | |
parent | 9447dc43941cd1c006cae934984524b7c957b803 (diff) | |
parent | 37c975545ec63320789962bf307f000f08fabd48 (diff) |
Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 vdso changes from Peter Anvin:
"This is the revamp of the 32-bit vdso and the associated cleanups.
This adds timekeeping support to the 32-bit vdso that we already have
in the 64-bit vdso. Although 32-bit x86 is legacy, it is likely to
remain in the embedded space for a very long time to come.
This removes the traditional COMPAT_VDSO support; the configuration
variable is reused for simply removing the 32-bit vdso, which will
produce correct results but obviously suffer a performance penalty.
Only one beta version of glibc was affected, but that version was
unfortunately included in one OpenSUSE release.
This is not the end of the vdso cleanups. Stefani and Andy have
agreed to continue work for the next kernel cycle; in fact Andy has
already produced another set of cleanups that came too late for this
cycle.
An incidental, but arguably important, change is that this ensures
that unused space in the VVAR page is properly zeroed. It wasn't
before, and would contain whatever garbage was left in memory by BIOS
or the bootloader. Since the VVAR page is accessible to user space
this had the potential of information leaks"
* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
x86, vdso: Fix the symbol versions on the 32-bit vDSO
x86, vdso, build: Don't rebuild 32-bit vdsos on every make
x86, vdso: Actually discard the .discard sections
x86, vdso: Fix size of get_unmapped_area()
x86, vdso: Finish removing VDSO32_PRELINK
x86, vdso: Move more vdso definitions into vdso.h
x86: Load the 32-bit vdso in place, just like the 64-bit vdsos
x86, vdso32: handle 32 bit vDSO larger one page
x86, vdso32: Disable stack protector, adjust optimizations
x86, vdso: Zero-pad the VVAR page
x86, vdso: Add 32 bit VDSO time support for 64 bit kernel
x86, vdso: Add 32 bit VDSO time support for 32 bit kernel
x86, vdso: Patch alternatives in the 32-bit VDSO
x86, vdso: Introduce VVAR marco for vdso32
x86, vdso: Cleanup __vdso_gettimeofday()
x86, vdso: Replace VVAR(vsyscall_gtod_data) by gtod macro
x86, vdso: __vdso_clock_gettime() cleanup
x86, vdso: Revamp vclock_gettime.c
mm: Add new func _install_special_mapping() to mmap.c
x86, vdso: Make vsyscall_gtod_data handling x86 generic
...
Diffstat (limited to 'arch/x86/vdso')
-rw-r--r-- | arch/x86/vdso/Makefile | 16 | ||||
-rw-r--r-- | arch/x86/vdso/vclock_gettime.c | 256 | ||||
-rw-r--r-- | arch/x86/vdso/vdso-layout.lds.S | 29 | ||||
-rw-r--r-- | arch/x86/vdso/vdso.S | 22 | ||||
-rw-r--r-- | arch/x86/vdso/vdso32-setup.c | 301 | ||||
-rw-r--r-- | arch/x86/vdso/vdso32.S | 21 | ||||
-rw-r--r-- | arch/x86/vdso/vdso32/vclock_gettime.c | 30 | ||||
-rw-r--r-- | arch/x86/vdso/vdso32/vdso32.lds.S | 15 | ||||
-rw-r--r-- | arch/x86/vdso/vdsox32.S | 22 | ||||
-rw-r--r-- | arch/x86/vdso/vma.c | 20 |
10 files changed, 349 insertions, 383 deletions
diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile index 9206ac7961a5..c580d1210ffe 100644 --- a/arch/x86/vdso/Makefile +++ b/arch/x86/vdso/Makefile @@ -23,7 +23,8 @@ vobjs-$(VDSOX32-y) += $(vobjx32s-compat) vobj64s := $(filter-out $(vobjx32s-compat),$(vobjs-y)) # files to link into kernel -obj-$(VDSO64-y) += vma.o vdso.o +obj-y += vma.o +obj-$(VDSO64-y) += vdso.o obj-$(VDSOX32-y) += vdsox32.o obj-$(VDSO32-y) += vdso32.o vdso32-setup.o @@ -138,7 +139,7 @@ override obj-dirs = $(dir $(obj)) $(obj)/vdso32/ targets += vdso32/vdso32.lds targets += $(vdso32-images) $(vdso32-images:=.dbg) -targets += vdso32/note.o $(vdso32.so-y:%=vdso32/%.o) +targets += vdso32/note.o vdso32/vclock_gettime.o $(vdso32.so-y:%=vdso32/%.o) extra-y += $(vdso32-images) @@ -148,8 +149,19 @@ 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 +KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector) +KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls) +KBUILD_CFLAGS_32 += -fno-omit-frame-pointer +$(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 eb5d7a56f8d4..16d686171e9a 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 <stefani@seibold.net> + * sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany + * * The code should have no internal unresolved relocations. * Check with readelf after changing. */ @@ -11,56 +14,55 @@ /* Disable profiling for userspace code: */ #define DISABLE_BRANCH_PROFILING -#include <linux/kernel.h> -#include <linux/posix-timers.h> -#include <linux/time.h> -#include <linux/string.h> -#include <asm/vsyscall.h> -#include <asm/fixmap.h> +#include <uapi/linux/time.h> #include <asm/vgtod.h> -#include <asm/timex.h> #include <asm/hpet.h> +#include <asm/vvar.h> #include <asm/unistd.h> -#include <asm/io.h> -#include <asm/pvclock.h> +#include <asm/msr.h> +#include <linux/math64.h> +#include <linux/time.h> #define gtod (&VVAR(vsyscall_gtod_data)) -notrace static cycle_t vread_tsc(void) +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); + +#ifdef CONFIG_HPET_TIMER +static inline u32 read_hpet_counter(const volatile void *addr) { - cycle_t ret; - u64 last; + return *(const volatile u32 *) (addr + HPET_COUNTER); +} +#endif - /* - * Empirically, a fence (of type that depends on the CPU) - * before rdtsc is enough to ensure that rdtsc is ordered - * with respect to loads. The various CPU manuals are unclear - * as to whether rdtsc can be reordered with later loads, - * but no one has ever seen it happen. - */ - rdtsc_barrier(); - ret = (cycle_t)vget_cycles(); +#ifndef BUILD_VDSO32 - last = VVAR(vsyscall_gtod_data).clock.cycle_last; +#include <linux/kernel.h> +#include <asm/vsyscall.h> +#include <asm/fixmap.h> +#include <asm/pvclock.h> - if (likely(ret >= last)) - return ret; +static notrace cycle_t vread_hpet(void) +{ + return read_hpet_counter((const void *)fix_to_virt(VSYSCALL_HPET)); +} - /* - * GCC likes to generate cmov here, but this branch is extremely - * predictable (it's just a funciton of time and the likely is - * very likely) and there's a data dependence, so force GCC - * to generate a branch instead. I don't barrier() because - * we don't actually need a barrier, and if this function - * ever gets inlined it will generate worse code. - */ - asm volatile (""); - return last; +notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) +{ + long ret; + asm("syscall" : "=a" (ret) : + "0" (__NR_clock_gettime), "D" (clock), "S" (ts) : "memory"); + return ret; } -static notrace cycle_t vread_hpet(void) +notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz) { - return readl((const void __iomem *)fix_to_virt(VSYSCALL_HPET) + HPET_COUNTER); + long ret; + + asm("syscall" : "=a" (ret) : + "0" (__NR_gettimeofday), "D" (tv), "S" (tz) : "memory"); + return ret; } #ifdef CONFIG_PARAVIRT_CLOCK @@ -124,7 +126,7 @@ static notrace cycle_t vread_pvclock(int *mode) *mode = VCLOCK_NONE; /* refer to tsc.c read_tsc() comment for rationale */ - last = VVAR(vsyscall_gtod_data).clock.cycle_last; + last = gtod->cycle_last; if (likely(ret >= last)) return ret; @@ -133,11 +135,30 @@ 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 read_hpet_counter((const void *)(&hpet_page)); +} +#endif + notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) { long ret; - asm("syscall" : "=a" (ret) : - "0" (__NR_clock_gettime),"D" (clock), "S" (ts) : "memory"); + + 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; } @@ -145,28 +166,79 @@ notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz) { long ret; - asm("syscall" : "=a" (ret) : - "0" (__NR_gettimeofday), "D" (tv), "S" (tz) : "memory"); + 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; + u64 last; + + /* + * Empirically, a fence (of type that depends on the CPU) + * before rdtsc is enough to ensure that rdtsc is ordered + * with respect to loads. The various CPU manuals are unclear + * as to whether rdtsc can be reordered with later loads, + * but no one has ever seen it happen. + */ + rdtsc_barrier(); + ret = (cycle_t)__native_read_tsc(); + + last = gtod->cycle_last; + + if (likely(ret >= last)) + return ret; + + /* + * GCC likes to generate cmov here, but this branch is extremely + * predictable (it's just a funciton of time and the likely is + * very likely) and there's a data dependence, so force GCC + * to generate a branch instead. I don't barrier() because + * we don't actually need a barrier, and if this function + * ever gets inlined it will generate worse code. + */ + asm volatile (""); + return last; +} notrace static inline u64 vgetsns(int *mode) { - long v; + u64 v; cycles_t cycles; - if (gtod->clock.vclock_mode == VCLOCK_TSC) + + if (gtod->vclock_mode == VCLOCK_TSC) cycles = vread_tsc(); - else if (gtod->clock.vclock_mode == VCLOCK_HPET) +#ifdef CONFIG_HPET_TIMER + else if (gtod->vclock_mode == VCLOCK_HPET) cycles = vread_hpet(); +#endif #ifdef CONFIG_PARAVIRT_CLOCK - else if (gtod->clock.vclock_mode == VCLOCK_PVCLOCK) + else if (gtod->vclock_mode == VCLOCK_PVCLOCK) cycles = vread_pvclock(mode); #endif else return 0; - v = (cycles - gtod->clock.cycle_last) & gtod->clock.mask; - return v * gtod->clock.mult; + v = (cycles - gtod->cycle_last) & gtod->mask; + return v * gtod->mult; } /* Code size doesn't matter (vdso is 4k anyway) and this is faster. */ @@ -176,106 +248,102 @@ notrace static int __always_inline do_realtime(struct timespec *ts) u64 ns; int mode; - ts->tv_nsec = 0; do { - seq = raw_read_seqcount_begin(>od->seq); - mode = gtod->clock.vclock_mode; + seq = gtod_read_begin(gtod); + mode = gtod->vclock_mode; ts->tv_sec = gtod->wall_time_sec; ns = gtod->wall_time_snsec; ns += vgetsns(&mode); - ns >>= gtod->clock.shift; - } while (unlikely(read_seqcount_retry(>od->seq, seq))); + ns >>= gtod->shift; + } while (unlikely(gtod_read_retry(gtod, seq))); + + ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns); + ts->tv_nsec = ns; - timespec_add_ns(ts, ns); 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; int mode; - ts->tv_nsec = 0; do { - seq = raw_read_seqcount_begin(>od->seq); - mode = gtod->clock.vclock_mode; + seq = gtod_read_begin(gtod); + mode = gtod->vclock_mode; ts->tv_sec = gtod->monotonic_time_sec; ns = gtod->monotonic_time_snsec; ns += vgetsns(&mode); - ns >>= gtod->clock.shift; - } while (unlikely(read_seqcount_retry(>od->seq, seq))); - timespec_add_ns(ts, ns); + ns >>= gtod->shift; + } while (unlikely(gtod_read_retry(gtod, seq))); + + ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns); + ts->tv_nsec = ns; return mode; } -notrace static int do_realtime_coarse(struct timespec *ts) +notrace static void do_realtime_coarse(struct timespec *ts) { unsigned long seq; do { - seq = raw_read_seqcount_begin(>od->seq); - ts->tv_sec = gtod->wall_time_coarse.tv_sec; - ts->tv_nsec = gtod->wall_time_coarse.tv_nsec; - } while (unlikely(read_seqcount_retry(>od->seq, seq))); - return 0; + seq = gtod_read_begin(gtod); + ts->tv_sec = gtod->wall_time_coarse_sec; + ts->tv_nsec = gtod->wall_time_coarse_nsec; + } while (unlikely(gtod_read_retry(gtod, seq))); } -notrace static int do_monotonic_coarse(struct timespec *ts) +notrace static void do_monotonic_coarse(struct timespec *ts) { unsigned long seq; do { - seq = raw_read_seqcount_begin(>od->seq); - ts->tv_sec = gtod->monotonic_time_coarse.tv_sec; - ts->tv_nsec = gtod->monotonic_time_coarse.tv_nsec; - } while (unlikely(read_seqcount_retry(>od->seq, seq))); - - return 0; + seq = gtod_read_begin(gtod); + ts->tv_sec = gtod->monotonic_time_coarse_sec; + ts->tv_nsec = gtod->monotonic_time_coarse_nsec; + } while (unlikely(gtod_read_retry(gtod, seq))); } notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts) { - int ret = VCLOCK_NONE; - switch (clock) { case CLOCK_REALTIME: - ret = do_realtime(ts); + if (do_realtime(ts) == VCLOCK_NONE) + goto fallback; break; case CLOCK_MONOTONIC: - ret = do_monotonic(ts); + if (do_monotonic(ts) == VCLOCK_NONE) + goto fallback; break; case CLOCK_REALTIME_COARSE: - return do_realtime_coarse(ts); + do_realtime_coarse(ts); + break; case CLOCK_MONOTONIC_COARSE: - return do_monotonic_coarse(ts); + do_monotonic_coarse(ts); + break; + default: + goto fallback; } - if (ret == VCLOCK_NONE) - return vdso_fallback_gettime(clock, ts); return 0; +fallback: + return vdso_fallback_gettime(clock, ts); } int clock_gettime(clockid_t, struct timespec *) __attribute__((weak, alias("__vdso_clock_gettime"))); notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz) { - long ret = VCLOCK_NONE; - if (likely(tv != NULL)) { - BUILD_BUG_ON(offsetof(struct timeval, tv_usec) != - offsetof(struct timespec, tv_nsec) || - sizeof(*tv) != sizeof(struct timespec)); - ret = do_realtime((struct timespec *)tv); + if (unlikely(do_realtime((struct timespec *)tv) == VCLOCK_NONE)) + return vdso_fallback_gtod(tv, tz); tv->tv_usec /= 1000; } if (unlikely(tz != NULL)) { - /* Avoid memcpy. Some old compilers fail to inline it */ - tz->tz_minuteswest = gtod->sys_tz.tz_minuteswest; - tz->tz_dsttime = gtod->sys_tz.tz_dsttime; + tz->tz_minuteswest = gtod->tz_minuteswest; + tz->tz_dsttime = gtod->tz_dsttime; } - if (ret == VCLOCK_NONE) - return vdso_fallback_gtod(tv, tz); return 0; } int gettimeofday(struct timeval *, struct timezone *) @@ -287,8 +355,8 @@ 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. */ - time_t result = ACCESS_ONCE(VVAR(vsyscall_gtod_data).wall_time_sec); + /* This is atomic on x86 so we don't need any locks. */ + time_t result = ACCESS_ONCE(gtod->wall_time_sec); if (t) *t = result; diff --git a/arch/x86/vdso/vdso-layout.lds.S b/arch/x86/vdso/vdso-layout.lds.S index 634a2cf62046..2e263f367b13 100644 --- a/arch/x86/vdso/vdso-layout.lds.S +++ b/arch/x86/vdso/vdso-layout.lds.S @@ -6,7 +6,25 @@ SECTIONS { - . = VDSO_PRELINK + SIZEOF_HEADERS; +#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 .gnu.hash : { *(.gnu.hash) } @@ -44,6 +62,11 @@ SECTIONS . = ALIGN(0x100); .text : { *(.text*) } :text =0x90909090 + + /DISCARD/ : { + *(.discard) + *(.discard.*) + } } /* @@ -61,4 +84,8 @@ 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/vdso.S b/arch/x86/vdso/vdso.S index 1e13eb8c9656..be3f23b09af5 100644 --- a/arch/x86/vdso/vdso.S +++ b/arch/x86/vdso/vdso.S @@ -1,21 +1,3 @@ -#include <asm/page_types.h> -#include <linux/linkage.h> +#include <asm/vdso.h> -__PAGE_ALIGNED_DATA - - .globl vdso_start, vdso_end - .align PAGE_SIZE -vdso_start: - .incbin "arch/x86/vdso/vdso.so" -vdso_end: - .align PAGE_SIZE /* extra data here leaks to userspace. */ - -.previous - - .globl vdso_pages - .bss - .align 8 - .type vdso_pages, @object -vdso_pages: - .zero (vdso_end - vdso_start + PAGE_SIZE - 1) / PAGE_SIZE * 8 - .size vdso_pages, .-vdso_pages +DEFINE_VDSO_IMAGE(vdso, "arch/x86/vdso/vdso.so") diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c index d6bfb876cfb0..00348980a3a6 100644 --- a/arch/x86/vdso/vdso32-setup.c +++ b/arch/x86/vdso/vdso32-setup.c @@ -16,6 +16,7 @@ #include <linux/mm.h> #include <linux/err.h> #include <linux/module.h> +#include <linux/slab.h> #include <asm/cpufeature.h> #include <asm/msr.h> @@ -25,17 +26,14 @@ #include <asm/tlbflush.h> #include <asm/vdso.h> #include <asm/proto.h> - -enum { - VDSO_DISABLED = 0, - VDSO_ENABLED = 1, - VDSO_COMPAT = 2, -}; +#include <asm/fixmap.h> +#include <asm/hpet.h> +#include <asm/vvar.h> #ifdef CONFIG_COMPAT_VDSO -#define VDSO_DEFAULT VDSO_COMPAT +#define VDSO_DEFAULT 0 #else -#define VDSO_DEFAULT VDSO_ENABLED +#define VDSO_DEFAULT 1 #endif #ifdef CONFIG_X86_64 @@ -44,13 +42,6 @@ enum { #endif /* - * This is the difference between the prelinked addresses in the vDSO images - * and the VDSO_HIGH_BASE address where CONFIG_COMPAT_VDSO places the vDSO - * in the user address space. - */ -#define VDSO_ADDR_ADJUST (VDSO_HIGH_BASE - (unsigned long)VDSO32_PRELINK) - -/* * Should the kernel map a VDSO page into processes and pass its * address down to glibc upon exec()? */ @@ -60,6 +51,9 @@ static int __init vdso_setup(char *s) { vdso_enabled = simple_strtoul(s, NULL, 0); + if (vdso_enabled > 1) + pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n"); + return 1; } @@ -76,124 +70,8 @@ __setup_param("vdso=", vdso32_setup, vdso_setup, 0); EXPORT_SYMBOL_GPL(vdso_enabled); #endif -static __init void reloc_symtab(Elf32_Ehdr *ehdr, - unsigned offset, unsigned size) -{ - Elf32_Sym *sym = (void *)ehdr + offset; - unsigned nsym = size / sizeof(*sym); - unsigned i; - - for(i = 0; i < nsym; i++, sym++) { - if (sym->st_shndx == SHN_UNDEF || - sym->st_shndx == SHN_ABS) - continue; /* skip */ - - if (sym->st_shndx > SHN_LORESERVE) { - printk(KERN_INFO "VDSO: unexpected st_shndx %x\n", - sym->st_shndx); - continue; - } - - switch(ELF_ST_TYPE(sym->st_info)) { - case STT_OBJECT: - case STT_FUNC: - case STT_SECTION: - case STT_FILE: - sym->st_value += VDSO_ADDR_ADJUST; - } - } -} - -static __init void reloc_dyn(Elf32_Ehdr *ehdr, unsigned offset) -{ - Elf32_Dyn *dyn = (void *)ehdr + offset; - - for(; dyn->d_tag != DT_NULL; dyn++) - switch(dyn->d_tag) { - case DT_PLTGOT: - case DT_HASH: - case DT_STRTAB: - case DT_SYMTAB: - case DT_RELA: - case DT_INIT: - case DT_FINI: - case DT_REL: - case DT_DEBUG: - case DT_JMPREL: - case DT_VERSYM: - case DT_VERDEF: - case DT_VERNEED: - case DT_ADDRRNGLO ... DT_ADDRRNGHI: - /* definitely pointers needing relocation */ - dyn->d_un.d_ptr += VDSO_ADDR_ADJUST; - break; - - case DT_ENCODING ... OLD_DT_LOOS-1: - case DT_LOOS ... DT_HIOS-1: - /* Tags above DT_ENCODING are pointers if - they're even */ - if (dyn->d_tag >= DT_ENCODING && - (dyn->d_tag & 1) == 0) - dyn->d_un.d_ptr += VDSO_ADDR_ADJUST; - break; - - case DT_VERDEFNUM: - case DT_VERNEEDNUM: - case DT_FLAGS_1: - case DT_RELACOUNT: - case DT_RELCOUNT: - case DT_VALRNGLO ... DT_VALRNGHI: - /* definitely not pointers */ - break; - - case OLD_DT_LOOS ... DT_LOOS-1: - case DT_HIOS ... DT_VALRNGLO-1: - default: - if (dyn->d_tag > DT_ENCODING) - printk(KERN_INFO "VDSO: unexpected DT_tag %x\n", - dyn->d_tag); - break; - } -} - -static __init void relocate_vdso(Elf32_Ehdr *ehdr) -{ - Elf32_Phdr *phdr; - Elf32_Shdr *shdr; - int i; - - BUG_ON(memcmp(ehdr->e_ident, ELFMAG, SELFMAG) != 0 || - !elf_check_arch_ia32(ehdr) || - ehdr->e_type != ET_DYN); - - ehdr->e_entry += VDSO_ADDR_ADJUST; - - /* rebase phdrs */ - phdr = (void *)ehdr + ehdr->e_phoff; - for (i = 0; i < ehdr->e_phnum; i++) { - phdr[i].p_vaddr += VDSO_ADDR_ADJUST; - - /* relocate dynamic stuff */ - if (phdr[i].p_type == PT_DYNAMIC) - reloc_dyn(ehdr, phdr[i].p_offset); - } - - /* rebase sections */ - shdr = (void *)ehdr + ehdr->e_shoff; - for(i = 0; i < ehdr->e_shnum; i++) { - if (!(shdr[i].sh_flags & SHF_ALLOC)) - continue; - - shdr[i].sh_addr += VDSO_ADDR_ADJUST; - - if (shdr[i].sh_type == SHT_SYMTAB || - shdr[i].sh_type == SHT_DYNSYM) - reloc_symtab(ehdr, shdr[i].sh_offset, - shdr[i].sh_size); - } -} - -static struct page *vdso32_pages[1]; +static struct page **vdso32_pages; +static unsigned vdso32_size; #ifdef CONFIG_X86_64 @@ -212,12 +90,6 @@ void syscall32_cpu_init(void) wrmsrl(MSR_CSTAR, ia32_cstar_target); } -#define compat_uses_vma 1 - -static inline void map_compat_vdso(int map) -{ -} - #else /* CONFIG_X86_32 */ #define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SEP)) @@ -241,64 +113,36 @@ void enable_sep_cpu(void) put_cpu(); } -static struct vm_area_struct gate_vma; - -static int __init gate_vma_init(void) -{ - gate_vma.vm_mm = NULL; - gate_vma.vm_start = FIXADDR_USER_START; - gate_vma.vm_end = FIXADDR_USER_END; - gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC; - gate_vma.vm_page_prot = __P101; - - return 0; -} - -#define compat_uses_vma 0 - -static void map_compat_vdso(int map) -{ - static int vdso_mapped; - - if (map == vdso_mapped) - return; - - vdso_mapped = map; - - __set_fixmap(FIX_VDSO, page_to_pfn(vdso32_pages[0]) << PAGE_SHIFT, - map ? PAGE_READONLY_EXEC : PAGE_NONE); - - /* flush stray tlbs */ - flush_tlb_all(); -} - #endif /* CONFIG_X86_64 */ int __init sysenter_setup(void) { - void *syscall_page = (void *)get_zeroed_page(GFP_ATOMIC); - const void *vsyscall; - size_t vsyscall_len; - - vdso32_pages[0] = virt_to_page(syscall_page); - -#ifdef CONFIG_X86_32 - gate_vma_init(); -#endif + char *vdso32_start, *vdso32_end; + int npages, i; +#ifdef CONFIG_COMPAT if (vdso32_syscall()) { - vsyscall = &vdso32_syscall_start; - vsyscall_len = &vdso32_syscall_end - &vdso32_syscall_start; - } else if (vdso32_sysenter()){ - vsyscall = &vdso32_sysenter_start; - vsyscall_len = &vdso32_sysenter_end - &vdso32_sysenter_start; + vdso32_start = vdso32_syscall_start; + vdso32_end = vdso32_syscall_end; + vdso32_pages = vdso32_syscall_pages; + } else +#endif + if (vdso32_sysenter()) { + vdso32_start = vdso32_sysenter_start; + vdso32_end = vdso32_sysenter_end; + vdso32_pages = vdso32_sysenter_pages; } else { - vsyscall = &vdso32_int80_start; - vsyscall_len = &vdso32_int80_end - &vdso32_int80_start; + vdso32_start = vdso32_int80_start; + vdso32_end = vdso32_int80_end; + vdso32_pages = vdso32_int80_pages; } - memcpy(syscall_page, vsyscall, vsyscall_len); - relocate_vdso(syscall_page); + npages = ((vdso32_end - vdso32_start) + PAGE_SIZE - 1) / PAGE_SIZE; + vdso32_size = npages << PAGE_SHIFT; + for (i = 0; i < npages; i++) + vdso32_pages[i] = virt_to_page(vdso32_start + i*PAGE_SIZE); + + patch_vdso32(vdso32_start, vdso32_size); return 0; } @@ -309,48 +153,73 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) struct mm_struct *mm = current->mm; unsigned long addr; int ret = 0; - bool compat; + struct vm_area_struct *vma; #ifdef CONFIG_X86_X32_ABI if (test_thread_flag(TIF_X32)) return x32_setup_additional_pages(bprm, uses_interp); #endif - if (vdso_enabled == VDSO_DISABLED) + if (vdso_enabled != 1) /* Other values all mean "disabled" */ return 0; down_write(&mm->mmap_sem); - /* Test compat mode once here, in case someone - changes it via sysctl */ - compat = (vdso_enabled == VDSO_COMPAT); + addr = get_unmapped_area(NULL, 0, vdso32_size + VDSO_OFFSET(VDSO_PREV_PAGES), 0, 0); + if (IS_ERR_VALUE(addr)) { + ret = addr; + goto up_fail; + } + + addr += VDSO_OFFSET(VDSO_PREV_PAGES); - map_compat_vdso(compat); + current->mm->context.vdso = (void *)addr; - if (compat) - addr = VDSO_HIGH_BASE; - else { - addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0); - if (IS_ERR_VALUE(addr)) { - ret = addr; - goto up_fail; - } + /* + * MAYWRITE to allow gdb to COW and set breakpoints + */ + ret = install_special_mapping(mm, + addr, + vdso32_size, + 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; } - current->mm->context.vdso = (void *)addr; + 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; - if (compat_uses_vma || !compat) { - /* - * 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); +#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); @@ -411,20 +280,12 @@ const char *arch_vma_name(struct vm_area_struct *vma) struct vm_area_struct *get_gate_vma(struct mm_struct *mm) { - /* - * Check to see if the corresponding task was created in compat vdso - * mode. - */ - if (mm && mm->context.vdso == (void *)VDSO_HIGH_BASE) - return &gate_vma; return NULL; } int in_gate_area(struct mm_struct *mm, unsigned long addr) { - const struct vm_area_struct *vma = get_gate_vma(mm); - - return vma && addr >= vma->vm_start && addr < vma->vm_end; + return 0; } int in_gate_area_no_mm(unsigned long addr) diff --git a/arch/x86/vdso/vdso32.S b/arch/x86/vdso/vdso32.S index 2ce5f82c333b..018bcd9f97b4 100644 --- a/arch/x86/vdso/vdso32.S +++ b/arch/x86/vdso/vdso32.S @@ -1,22 +1,9 @@ -#include <linux/init.h> +#include <asm/vdso.h> -__INITDATA +DEFINE_VDSO_IMAGE(vdso32_int80, "arch/x86/vdso/vdso32-int80.so") - .globl vdso32_int80_start, vdso32_int80_end -vdso32_int80_start: - .incbin "arch/x86/vdso/vdso32-int80.so" -vdso32_int80_end: - - .globl vdso32_syscall_start, vdso32_syscall_end -vdso32_syscall_start: #ifdef CONFIG_COMPAT - .incbin "arch/x86/vdso/vdso32-syscall.so" +DEFINE_VDSO_IMAGE(vdso32_syscall, "arch/x86/vdso/vdso32-syscall.so") #endif -vdso32_syscall_end: - - .globl vdso32_sysenter_start, vdso32_sysenter_end -vdso32_sysenter_start: - .incbin "arch/x86/vdso/vdso32-sysenter.so" -vdso32_sysenter_end: -__FINIT +DEFINE_VDSO_IMAGE(vdso32_sysenter, "arch/x86/vdso/vdso32-sysenter.so") diff --git a/arch/x86/vdso/vdso32/vclock_gettime.c b/arch/x86/vdso/vdso32/vclock_gettime.c new file mode 100644 index 000000000000..175cc72c0f68 --- /dev/null +++ b/arch/x86/vdso/vdso32/vclock_gettime.c @@ -0,0 +1,30 @@ +#define BUILD_VDSO32 + +#ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE +#undef CONFIG_OPTIMIZE_INLINING +#endif + +#undef CONFIG_X86_PPRO_FENCE + +#ifdef CONFIG_X86_64 + +/* + * in case of a 32 bit VDSO for a 64 bit kernel fake a 32 bit kernel + * configuration + */ +#undef CONFIG_64BIT +#undef CONFIG_X86_64 +#undef CONFIG_ILLEGAL_POINTER_VALUE +#undef CONFIG_SPARSEMEM_VMEMMAP +#undef CONFIG_NR_CPUS + +#define CONFIG_X86_32 1 +#define CONFIG_PAGE_OFFSET 0 +#define CONFIG_ILLEGAL_POINTER_VALUE 0 +#define CONFIG_NR_CPUS 1 + +#define BUILD_VDSO32_64 + +#endif + +#include "../vclock_gettime.c" diff --git a/arch/x86/vdso/vdso32/vdso32.lds.S b/arch/x86/vdso/vdso32/vdso32.lds.S index 976124bb5f92..aadb8b9994cd 100644 --- a/arch/x86/vdso/vdso32/vdso32.lds.S +++ b/arch/x86/vdso/vdso32/vdso32.lds.S @@ -8,7 +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. */ @@ -19,6 +23,13 @@ ENTRY(__kernel_vsyscall); */ VERSION { + LINUX_2.6 { + global: + __vdso_clock_gettime; + __vdso_gettimeofday; + __vdso_time; + }; + LINUX_2.5 { global: __kernel_vsyscall; @@ -31,7 +42,9 @@ VERSION /* * Symbols we define here called VDSO* get their values into vdso32-syms.h. */ -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; diff --git a/arch/x86/vdso/vdsox32.S b/arch/x86/vdso/vdsox32.S index 295f1c7543d8..f4aa34e7f370 100644 --- a/arch/x86/vdso/vdsox32.S +++ b/arch/x86/vdso/vdsox32.S @@ -1,21 +1,3 @@ -#include <asm/page_types.h> -#include <linux/linkage.h> +#include <asm/vdso.h> -__PAGE_ALIGNED_DATA - - .globl vdsox32_start, vdsox32_end - .align PAGE_SIZE -vdsox32_start: - .incbin "arch/x86/vdso/vdsox32.so" -vdsox32_end: - .align PAGE_SIZE /* extra data here leaks to userspace. */ - -.previous - - .globl vdsox32_pages - .bss - .align 8 - .type vdsox32_pages, @object -vdsox32_pages: - .zero (vdsox32_end - vdsox32_start + PAGE_SIZE - 1) / PAGE_SIZE * 8 - .size vdsox32_pages, .-vdsox32_pages +DEFINE_VDSO_IMAGE(vdsox32, "arch/x86/vdso/vdsox32.so") diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c index 431e87544411..1ad102613127 100644 --- a/arch/x86/vdso/vma.c +++ b/arch/x86/vdso/vma.c @@ -16,20 +16,22 @@ #include <asm/vdso.h> #include <asm/page.h> +#if defined(CONFIG_X86_64) unsigned int __read_mostly vdso_enabled = 1; -extern char vdso_start[], vdso_end[]; +DECLARE_VDSO_IMAGE(vdso); extern unsigned short vdso_sync_cpuid; - -extern struct page *vdso_pages[]; static unsigned vdso_size; #ifdef CONFIG_X86_X32_ABI -extern char vdsox32_start[], vdsox32_end[]; -extern struct page *vdsox32_pages[]; +DECLARE_VDSO_IMAGE(vdsox32); static unsigned vdsox32_size; +#endif +#endif -static void __init patch_vdsox32(void *vdso, size_t len) +#if defined(CONFIG_X86_32) || defined(CONFIG_X86_X32_ABI) || \ + defined(CONFIG_COMPAT) +void __init patch_vdso32(void *vdso, size_t len) { Elf32_Ehdr *hdr = vdso; Elf32_Shdr *sechdrs, *alt_sec = 0; @@ -52,7 +54,7 @@ static void __init patch_vdsox32(void *vdso, size_t len) } /* If we get here, it's probably a bug. */ - pr_warning("patch_vdsox32: .altinstructions not found\n"); + pr_warning("patch_vdso32: .altinstructions not found\n"); return; /* nothing to patch */ found: @@ -61,6 +63,7 @@ found: } #endif +#if defined(CONFIG_X86_64) static void __init patch_vdso64(void *vdso, size_t len) { Elf64_Ehdr *hdr = vdso; @@ -104,7 +107,7 @@ static int __init init_vdso(void) vdso_pages[i] = virt_to_page(vdso_start + i*PAGE_SIZE); #ifdef CONFIG_X86_X32_ABI - patch_vdsox32(vdsox32_start, vdsox32_end - vdsox32_start); + patch_vdso32(vdsox32_start, vdsox32_end - vdsox32_start); npages = (vdsox32_end - vdsox32_start + PAGE_SIZE - 1) / PAGE_SIZE; vdsox32_size = npages << PAGE_SHIFT; for (i = 0; i < npages; i++) @@ -204,3 +207,4 @@ static __init int vdso_setup(char *s) return 0; } __setup("vdso=", vdso_setup); +#endif |