diff options
Diffstat (limited to 'arch/x86/vdso')
-rw-r--r-- | arch/x86/vdso/.gitignore | 5 | ||||
-rw-r--r-- | arch/x86/vdso/Makefile | 90 | ||||
-rw-r--r-- | arch/x86/vdso/vclock_gettime.c | 26 | ||||
-rw-r--r-- | arch/x86/vdso/vdso-layout.lds.S | 40 | ||||
-rw-r--r-- | arch/x86/vdso/vdso.S | 3 | ||||
-rw-r--r-- | arch/x86/vdso/vdso.lds.S | 7 | ||||
-rw-r--r-- | arch/x86/vdso/vdso2c.c | 173 | ||||
-rw-r--r-- | arch/x86/vdso/vdso2c.h | 163 | ||||
-rw-r--r-- | arch/x86/vdso/vdso32-setup.c | 203 | ||||
-rw-r--r-- | arch/x86/vdso/vdso32.S | 9 | ||||
-rw-r--r-- | arch/x86/vdso/vdso32/vdso32.lds.S | 15 | ||||
-rw-r--r-- | arch/x86/vdso/vdsox32.S | 3 | ||||
-rw-r--r-- | arch/x86/vdso/vdsox32.lds.S | 7 | ||||
-rw-r--r-- | arch/x86/vdso/vma.c | 236 |
14 files changed, 556 insertions, 424 deletions
diff --git a/arch/x86/vdso/.gitignore b/arch/x86/vdso/.gitignore index 3282874..aae8ffd 100644 --- a/arch/x86/vdso/.gitignore +++ b/arch/x86/vdso/.gitignore @@ -1,8 +1,7 @@ vdso.lds -vdso-syms.lds vdsox32.lds -vdsox32-syms.lds -vdso32-syms.lds vdso32-syscall-syms.lds vdso32-sysenter-syms.lds vdso32-int80-syms.lds +vdso-image-*.c +vdso2c diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile index c580d12..895d4b1 100644 --- a/arch/x86/vdso/Makefile +++ b/arch/x86/vdso/Makefile @@ -24,15 +24,30 @@ vobj64s := $(filter-out $(vobjx32s-compat),$(vobjs-y)) # files to link into kernel obj-y += vma.o -obj-$(VDSO64-y) += vdso.o -obj-$(VDSOX32-y) += vdsox32.o -obj-$(VDSO32-y) += vdso32.o vdso32-setup.o + +# vDSO images to build +vdso_img-$(VDSO64-y) += 64 +vdso_img-$(VDSOX32-y) += x32 +vdso_img-$(VDSO32-y) += 32-int80 +vdso_img-$(CONFIG_COMPAT) += 32-syscall +vdso_img-$(VDSO32-y) += 32-sysenter + +obj-$(VDSO32-y) += vdso32-setup.o vobjs := $(foreach F,$(vobj64s),$(obj)/$F) $(obj)/vdso.o: $(obj)/vdso.so -targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y) +targets += vdso.lds $(vobjs-y) + +# Build the vDSO image C files and link them in. +vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o) +vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c) +vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg) +obj-y += $(vdso_img_objs) +targets += $(vdso_img_cfiles) +targets += $(vdso_img_sodbg) +.SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c) export CPPFLAGS_vdso.lds += -P -C @@ -41,14 +56,18 @@ VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \ -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \ $(DISABLE_LTO) -$(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so - -$(obj)/vdso.so.dbg: $(src)/vdso.lds $(vobjs) FORCE +$(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE $(call if_changed,vdso) -$(obj)/%.so: OBJCOPYFLAGS := -S -$(obj)/%.so: $(obj)/%.so.dbg FORCE - $(call if_changed,objcopy) +hostprogs-y += vdso2c + +quiet_cmd_vdso2c = VDSO2C $@ +define cmd_vdso2c + $(obj)/vdso2c $< $@ +endef + +$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso2c FORCE + $(call if_changed,vdso2c) # # Don't omit frame pointers for ease of userspace debugging, but do @@ -68,22 +87,6 @@ CFLAGS_REMOVE_vclock_gettime.o = -pg CFLAGS_REMOVE_vgetcpu.o = -pg CFLAGS_REMOVE_vvar.o = -pg -targets += vdso-syms.lds -obj-$(VDSO64-y) += vdso-syms.lds - -# -# Match symbols in the DSO that look like VDSO*; produce a file of constants. -# -sed-vdsosym := -e 's/^00*/0/' \ - -e 's/^\([0-9a-fA-F]*\) . \(VDSO[a-zA-Z0-9_]*\)$$/\2 = 0x\1;/p' -quiet_cmd_vdsosym = VDSOSYM $@ -define cmd_vdsosym - $(NM) $< | LC_ALL=C sed -n $(sed-vdsosym) | LC_ALL=C sort > $@ -endef - -$(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE - $(call if_changed,vdsosym) - # # X32 processes use x32 vDSO to access 64bit kernel data. # @@ -94,9 +97,6 @@ $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE # so that it can reach 64bit address space with 64bit pointers. # -targets += vdsox32-syms.lds -obj-$(VDSOX32-y) += vdsox32-syms.lds - CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds) VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \ -Wl,-soname=linux-vdso.so.1 \ @@ -113,9 +113,7 @@ quiet_cmd_x32 = X32 $@ $(obj)/%-x32.o: $(obj)/%.o FORCE $(call if_changed,x32) -targets += vdsox32.so vdsox32.so.dbg vdsox32.lds $(vobjx32s-y) - -$(obj)/vdsox32.o: $(src)/vdsox32.S $(obj)/vdsox32.so +targets += vdsox32.lds $(vobjx32s-y) $(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE $(call if_changed,vdso) @@ -123,7 +121,6 @@ $(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE # # Build multiple 32-bit vDSO images to choose from at boot time. # -obj-$(VDSO32-y) += vdso32-syms.lds vdso32.so-$(VDSO32-y) += int80 vdso32.so-$(CONFIG_COMPAT) += syscall vdso32.so-$(VDSO32-y) += sysenter @@ -138,10 +135,8 @@ VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1 override obj-dirs = $(dir $(obj)) $(obj)/vdso32/ targets += vdso32/vdso32.lds -targets += $(vdso32-images) $(vdso32-images:=.dbg) targets += vdso32/note.o vdso32/vclock_gettime.o $(vdso32.so-y:%=vdso32/%.o) - -extra-y += $(vdso32-images) +targets += vdso32/vclock_gettime.o $(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%) @@ -166,27 +161,6 @@ $(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \ $(obj)/vdso32/%.o $(call if_changed,vdso) -# Make vdso32-*-syms.lds from each image, and then make sure they match. -# The only difference should be that some do not define VDSO32_SYSENTER_RETURN. - -targets += vdso32-syms.lds $(vdso32.so-y:%=vdso32-%-syms.lds) - -quiet_cmd_vdso32sym = VDSOSYM $@ -define cmd_vdso32sym - if LC_ALL=C sort -u $(filter-out FORCE,$^) > $(@D)/.tmp_$(@F) && \ - $(foreach H,$(filter-out FORCE,$^),\ - if grep -q VDSO32_SYSENTER_RETURN $H; \ - then diff -u $(@D)/.tmp_$(@F) $H; \ - else sed /VDSO32_SYSENTER_RETURN/d $(@D)/.tmp_$(@F) | \ - diff -u - $H; fi &&) : ;\ - then mv -f $(@D)/.tmp_$(@F) $@; \ - else rm -f $(@D)/.tmp_$(@F); exit 1; \ - fi -endef - -$(obj)/vdso32-syms.lds: $(vdso32.so-y:%=$(obj)/vdso32-%-syms.lds) FORCE - $(call if_changed,vdso32sym) - # # The DSO images are built using a special linker script. # @@ -197,7 +171,7 @@ quiet_cmd_vdso = VDSO $@ sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@' VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \ - $(LTO_CFLAGS) + -Wl,-Bsymbolic $(LTO_CFLAGS) GCOV_PROFILE := n # diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c index 16d6861..b2e4f49 100644 --- a/arch/x86/vdso/vclock_gettime.c +++ b/arch/x86/vdso/vclock_gettime.c @@ -30,9 +30,12 @@ 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) +extern u8 hpet_page + __attribute__((visibility("hidden"))); + +static notrace cycle_t vread_hpet(void) { - return *(const volatile u32 *) (addr + HPET_COUNTER); + return *(const volatile u32 *)(&hpet_page + HPET_COUNTER); } #endif @@ -43,11 +46,6 @@ static inline u32 read_hpet_counter(const volatile void *addr) #include <asm/fixmap.h> #include <asm/pvclock.h> -static notrace cycle_t vread_hpet(void) -{ - return read_hpet_counter((const void *)fix_to_virt(VSYSCALL_HPET)); -} - notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) { long ret; @@ -137,16 +135,6 @@ static notrace cycle_t vread_pvclock(int *mode) #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; @@ -154,7 +142,7 @@ notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) asm( "mov %%ebx, %%edx \n" "mov %2, %%ebx \n" - "call VDSO32_vsyscall \n" + "call __kernel_vsyscall \n" "mov %%edx, %%ebx \n" : "=a" (ret) : "0" (__NR_clock_gettime), "g" (clock), "c" (ts) @@ -169,7 +157,7 @@ notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz) asm( "mov %%ebx, %%edx \n" "mov %2, %%ebx \n" - "call VDSO32_vsyscall \n" + "call __kernel_vsyscall \n" "mov %%edx, %%ebx \n" : "=a" (ret) : "0" (__NR_gettimeofday), "g" (tv), "c" (tz) diff --git a/arch/x86/vdso/vdso-layout.lds.S b/arch/x86/vdso/vdso-layout.lds.S index 9df017a..2ec72f6 100644 --- a/arch/x86/vdso/vdso-layout.lds.S +++ b/arch/x86/vdso/vdso-layout.lds.S @@ -1,3 +1,5 @@ +#include <asm/vdso.h> + /* * Linker script for vDSO. This is an ELF shared object prelinked to * its virtual address, and with only one read-only segment. @@ -6,20 +8,6 @@ SECTIONS { -#ifdef BUILD_VDSO32 -#include <asm/vdso32.h> - - hpet_page = . - VDSO_OFFSET(VDSO_HPET_PAGE); - - 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 -#endif . = SIZEOF_HEADERS; .hash : { *(.hash) } :text @@ -60,10 +48,30 @@ SECTIONS .text : { *(.text*) } :text =0x90909090, /* - * The comma above works around a bug in gold: - * https://sourceware.org/bugzilla/show_bug.cgi?id=16804 + * The remainder of the vDSO consists of special pages that are + * shared between the kernel and userspace. It needs to be at the + * end so that it doesn't overlap the mapping of the actual + * vDSO image. */ + . = ALIGN(PAGE_SIZE); + vvar_page = .; + + /* Place all vvars at the offsets in asm/vvar.h. */ +#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset; +#define __VVAR_KERNEL_LDS +#include <asm/vvar.h> +#undef __VVAR_KERNEL_LDS +#undef EMIT_VVAR + + . = vvar_page + PAGE_SIZE; + + hpet_page = .; + . = . + PAGE_SIZE; + + . = ALIGN(PAGE_SIZE); + end_mapping = .; + /DISCARD/ : { *(.discard) *(.discard.*) diff --git a/arch/x86/vdso/vdso.S b/arch/x86/vdso/vdso.S deleted file mode 100644 index be3f23b..0000000 --- a/arch/x86/vdso/vdso.S +++ /dev/null @@ -1,3 +0,0 @@ -#include <asm/vdso.h> - -DEFINE_VDSO_IMAGE(vdso, "arch/x86/vdso/vdso.so") diff --git a/arch/x86/vdso/vdso.lds.S b/arch/x86/vdso/vdso.lds.S index b96b267..75e3404 100644 --- a/arch/x86/vdso/vdso.lds.S +++ b/arch/x86/vdso/vdso.lds.S @@ -1,14 +1,11 @@ /* * Linker script for 64-bit vDSO. * We #include the file to define the layout details. - * Here we only choose the prelinked virtual address. * * This file defines the version script giving the user-exported symbols in - * the DSO. We can define local symbols here called VDSO* to make their - * values visible using the asm-x86/vdso.h macros from the kernel proper. + * the DSO. */ -#define VDSO_PRELINK 0xffffffffff700000 #include "vdso-layout.lds.S" /* @@ -28,5 +25,3 @@ VERSION { local: *; }; } - -VDSO64_PRELINK = VDSO_PRELINK; diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c new file mode 100644 index 0000000..deabaf5 --- /dev/null +++ b/arch/x86/vdso/vdso2c.c @@ -0,0 +1,173 @@ +#include <inttypes.h> +#include <stdint.h> +#include <unistd.h> +#include <stdarg.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <fcntl.h> +#include <err.h> + +#include <sys/mman.h> +#include <sys/types.h> + +#include <linux/elf.h> +#include <linux/types.h> + +const char *outfilename; + +/* Symbols that we need in vdso2c. */ +enum { + sym_vvar_page, + sym_hpet_page, + sym_end_mapping, +}; + +const int special_pages[] = { + sym_vvar_page, + sym_hpet_page, +}; + +char const * const required_syms[] = { + [sym_vvar_page] = "vvar_page", + [sym_hpet_page] = "hpet_page", + [sym_end_mapping] = "end_mapping", + "VDSO32_NOTE_MASK", + "VDSO32_SYSENTER_RETURN", + "__kernel_vsyscall", + "__kernel_sigreturn", + "__kernel_rt_sigreturn", +}; + +__attribute__((format(printf, 1, 2))) __attribute__((noreturn)) +static void fail(const char *format, ...) +{ + va_list ap; + va_start(ap, format); + fprintf(stderr, "Error: "); + vfprintf(stderr, format, ap); + unlink(outfilename); + exit(1); + va_end(ap); +} + +/* + * Evil macros to do a little-endian read. + */ +#define GLE(x, bits, ifnot) \ + __builtin_choose_expr( \ + (sizeof(x) == bits/8), \ + (__typeof__(x))le##bits##toh(x), ifnot) + +extern void bad_get_le(uint64_t); +#define LAST_LE(x) \ + __builtin_choose_expr(sizeof(x) == 1, (x), bad_get_le(x)) + +#define GET_LE(x) \ + GLE(x, 64, GLE(x, 32, GLE(x, 16, LAST_LE(x)))) + +#define NSYMS (sizeof(required_syms) / sizeof(required_syms[0])) + +#define BITS 64 +#define GOFUNC go64 +#define Elf_Ehdr Elf64_Ehdr +#define Elf_Shdr Elf64_Shdr +#define Elf_Phdr Elf64_Phdr +#define Elf_Sym Elf64_Sym +#define Elf_Dyn Elf64_Dyn +#include "vdso2c.h" +#undef BITS +#undef GOFUNC +#undef Elf_Ehdr +#undef Elf_Shdr +#undef Elf_Phdr +#undef Elf_Sym +#undef Elf_Dyn + +#define BITS 32 +#define GOFUNC go32 +#define Elf_Ehdr Elf32_Ehdr +#define Elf_Shdr Elf32_Shdr +#define Elf_Phdr Elf32_Phdr +#define Elf_Sym Elf32_Sym +#define Elf_Dyn Elf32_Dyn +#include "vdso2c.h" +#undef BITS +#undef GOFUNC +#undef Elf_Ehdr +#undef Elf_Shdr +#undef Elf_Phdr +#undef Elf_Sym +#undef Elf_Dyn + +static void go(void *addr, size_t len, FILE *outfile, const char *name) +{ + Elf64_Ehdr *hdr = (Elf64_Ehdr *)addr; + + if (hdr->e_ident[EI_CLASS] == ELFCLASS64) { + go64(addr, len, outfile, name); + } else if (hdr->e_ident[EI_CLASS] == ELFCLASS32) { + go32(addr, len, outfile, name); + } else { + fail("unknown ELF class\n"); + } +} + +int main(int argc, char **argv) +{ + int fd; + off_t len; + void *addr; + FILE *outfile; + char *name, *tmp; + int namelen; + + if (argc != 3) { + printf("Usage: vdso2c INPUT OUTPUT\n"); + return 1; + } + + /* + * Figure out the struct name. If we're writing to a .so file, + * generate raw output insted. + */ + name = strdup(argv[2]); + namelen = strlen(name); + if (namelen >= 3 && !strcmp(name + namelen - 3, ".so")) { + name = NULL; + } else { + tmp = strrchr(name, '/'); + if (tmp) + name = tmp + 1; + tmp = strchr(name, '.'); + if (tmp) + *tmp = '\0'; + for (tmp = name; *tmp; tmp++) + if (*tmp == '-') + *tmp = '_'; + } + + fd = open(argv[1], O_RDONLY); + if (fd == -1) + err(1, "%s", argv[1]); + + len = lseek(fd, 0, SEEK_END); + if (len == (off_t)-1) + err(1, "lseek"); + + addr = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); + if (addr == MAP_FAILED) + err(1, "mmap"); + + outfilename = argv[2]; + outfile = fopen(outfilename, "w"); + if (!outfile) + err(1, "%s", argv[2]); + + go(addr, (size_t)len, outfile, name); + + munmap(addr, len); + fclose(outfile); + + return 0; +} diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h new file mode 100644 index 0000000..d1e99e1 --- /dev/null +++ b/arch/x86/vdso/vdso2c.h @@ -0,0 +1,163 @@ +/* + * This file is included twice from vdso2c.c. It generates code for 32-bit + * and 64-bit vDSOs. We need both for 64-bit builds, since 32-bit vDSOs + * are built for 32-bit userspace. + */ + +static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name) +{ + int found_load = 0; + unsigned long load_size = -1; /* Work around bogus warning */ + unsigned long data_size; + Elf_Ehdr *hdr = (Elf_Ehdr *)addr; + int i; + unsigned long j; + Elf_Shdr *symtab_hdr = NULL, *strtab_hdr, *secstrings_hdr, + *alt_sec = NULL; + Elf_Dyn *dyn = 0, *dyn_end = 0; + const char *secstrings; + uint64_t syms[NSYMS] = {}; + + Elf_Phdr *pt = (Elf_Phdr *)(addr + GET_LE(hdr->e_phoff)); + + /* Walk the segment table. */ + for (i = 0; i < GET_LE(hdr->e_phnum); i++) { + if (GET_LE(pt[i].p_type) == PT_LOAD) { + if (found_load) + fail("multiple PT_LOAD segs\n"); + + if (GET_LE(pt[i].p_offset) != 0 || + GET_LE(pt[i].p_vaddr) != 0) + fail("PT_LOAD in wrong place\n"); + + if (GET_LE(pt[i].p_memsz) != GET_LE(pt[i].p_filesz)) + fail("cannot handle memsz != filesz\n"); + + load_size = GET_LE(pt[i].p_memsz); + found_load = 1; + } else if (GET_LE(pt[i].p_type) == PT_DYNAMIC) { + dyn = addr + GET_LE(pt[i].p_offset); + dyn_end = addr + GET_LE(pt[i].p_offset) + + GET_LE(pt[i].p_memsz); + } + } + if (!found_load) + fail("no PT_LOAD seg\n"); + data_size = (load_size + 4095) / 4096 * 4096; + + /* Walk the dynamic table */ + for (i = 0; dyn + i < dyn_end && + GET_LE(dyn[i].d_tag) != DT_NULL; i++) { + typeof(dyn[i].d_tag) tag = GET_LE(dyn[i].d_tag); + if (tag == DT_REL || tag == DT_RELSZ || + tag == DT_RELENT || tag == DT_TEXTREL) + fail("vdso image contains dynamic relocations\n"); + } + + /* Walk the section table */ + secstrings_hdr = addr + GET_LE(hdr->e_shoff) + + GET_LE(hdr->e_shentsize)*GET_LE(hdr->e_shstrndx); + secstrings = addr + GET_LE(secstrings_hdr->sh_offset); + for (i = 0; i < GET_LE(hdr->e_shnum); i++) { + Elf_Shdr *sh = addr + GET_LE(hdr->e_shoff) + + GET_LE(hdr->e_shentsize) * i; + if (GET_LE(sh->sh_type) == SHT_SYMTAB) + symtab_hdr = sh; + + if (!strcmp(secstrings + GET_LE(sh->sh_name), + ".altinstructions")) + alt_sec = sh; + } + + if (!symtab_hdr) + fail("no symbol table\n"); + + strtab_hdr = addr + GET_LE(hdr->e_shoff) + + GET_LE(hdr->e_shentsize) * GET_LE(symtab_hdr->sh_link); + + /* Walk the symbol table */ + for (i = 0; + i < GET_LE(symtab_hdr->sh_size) / GET_LE(symtab_hdr->sh_entsize); + i++) { + int k; + Elf_Sym *sym = addr + GET_LE(symtab_hdr->sh_offset) + + GET_LE(symtab_hdr->sh_entsize) * i; + const char *name = addr + GET_LE(strtab_hdr->sh_offset) + + GET_LE(sym->st_name); + for (k = 0; k < NSYMS; k++) { + if (!strcmp(name, required_syms[k])) { + if (syms[k]) { + fail("duplicate symbol %s\n", + required_syms[k]); + } + syms[k] = GET_LE(sym->st_value); + } + } + } + + /* Validate mapping addresses. */ + for (i = 0; i < sizeof(special_pages) / sizeof(special_pages[0]); i++) { + if (!syms[i]) + continue; /* The mapping isn't used; ignore it. */ + + if (syms[i] % 4096) + fail("%s must be a multiple of 4096\n", + required_syms[i]); + if (syms[i] < data_size) + fail("%s must be after the text mapping\n", + required_syms[i]); + if (syms[sym_end_mapping] < syms[i] + 4096) + fail("%s overruns end_mapping\n", required_syms[i]); + } + if (syms[sym_end_mapping] % 4096) + fail("end_mapping must be a multiple of 4096\n"); + + /* Remove sections. */ + hdr->e_shoff = 0; + hdr->e_shentsize = 0; + hdr->e_shnum = 0; + hdr->e_shstrndx = htole16(SHN_UNDEF); + + if (!name) { + fwrite(addr, load_size, 1, outfile); + return; + } + + fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n"); + fprintf(outfile, "#include <linux/linkage.h>\n"); + fprintf(outfile, "#include <asm/page_types.h>\n"); + fprintf(outfile, "#include <asm/vdso.h>\n"); + fprintf(outfile, "\n"); + fprintf(outfile, + "static unsigned char raw_data[%lu] __page_aligned_data = {", + data_size); + for (j = 0; j < load_size; j++) { + if (j % 10 == 0) + fprintf(outfile, "\n\t"); + fprintf(outfile, "0x%02X, ", (int)((unsigned char *)addr)[j]); + } + fprintf(outfile, "\n};\n\n"); + + fprintf(outfile, "static struct page *pages[%lu];\n\n", + data_size / 4096); + + fprintf(outfile, "const struct vdso_image %s = {\n", name); + fprintf(outfile, "\t.data = raw_data,\n"); + fprintf(outfile, "\t.size = %lu,\n", data_size); + fprintf(outfile, "\t.text_mapping = {\n"); + fprintf(outfile, "\t\t.name = \"[vdso]\",\n"); + fprintf(outfile, "\t\t.pages = pages,\n"); + fprintf(outfile, "\t},\n"); + if (alt_sec) { + fprintf(outfile, "\t.alt = %lu,\n", + (unsigned long)GET_LE(alt_sec->sh_offset)); + fprintf(outfile, "\t.alt_len = %lu,\n", + (unsigned long)GET_LE(alt_sec->sh_size)); + } + for (i = 0; i < NSYMS; i++) { + if (syms[i]) + fprintf(outfile, "\t.sym_%s = 0x%" PRIx64 ",\n", + required_syms[i], syms[i]); + } + fprintf(outfile, "};\n"); +} diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c index 0034898..e4f7781 100644 --- a/arch/x86/vdso/vdso32-setup.c +++ b/arch/x86/vdso/vdso32-setup.c @@ -8,27 +8,12 @@ #include <linux/init.h> #include <linux/smp.h> -#include <linux/thread_info.h> -#include <linux/sched.h> -#include <linux/gfp.h> -#include <linux/string.h> -#include <linux/elf.h> -#include <linux/mm.h> -#include <linux/err.h> -#include <linux/module.h> -#include <linux/slab.h> +#include <linux/kernel.h> +#include <linux/mm_types.h> #include <asm/cpufeature.h> -#include <asm/msr.h> -#include <asm/pgtable.h> -#include <asm/unistd.h> -#include <asm/elf.h> -#include <asm/tlbflush.h> +#include <asm/processor.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 @@ -36,22 +21,17 @@ #define VDSO_DEFAULT 1 #endif -#ifdef CONFIG_X86_64 -#define vdso_enabled sysctl_vsyscall32 -#define arch_setup_additional_pages syscall32_setup_pages -#endif - /* * Should the kernel map a VDSO page into processes and pass its * address down to glibc upon exec()? */ -unsigned int __read_mostly vdso_enabled = VDSO_DEFAULT; +unsigned int __read_mostly vdso32_enabled = VDSO_DEFAULT; -static int __init vdso_setup(char *s) +static int __init vdso32_setup(char *s) { - vdso_enabled = simple_strtoul(s, NULL, 0); + vdso32_enabled = simple_strtoul(s, NULL, 0); - if (vdso_enabled > 1) + if (vdso32_enabled > 1) pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n"); return 1; @@ -62,177 +42,45 @@ static int __init vdso_setup(char *s) * behavior on both 64-bit and 32-bit kernels. * On 32-bit kernels, vdso=[012] means the same thing. */ -__setup("vdso32=", vdso_setup); +__setup("vdso32=", vdso32_setup); #ifdef CONFIG_X86_32 -__setup_param("vdso=", vdso32_setup, vdso_setup, 0); - -EXPORT_SYMBOL_GPL(vdso_enabled); +__setup_param("vdso=", vdso_setup, vdso32_setup, 0); #endif -static struct page **vdso32_pages; -static unsigned vdso32_size; - #ifdef CONFIG_X86_64 #define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SYSENTER32)) #define vdso32_syscall() (boot_cpu_has(X86_FEATURE_SYSCALL32)) -/* May not be __init: called during resume */ -void syscall32_cpu_init(void) -{ - /* Load these always in case some future AMD CPU supports - SYSENTER from compat mode too. */ - wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS); - wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL); - wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target); - - wrmsrl(MSR_CSTAR, ia32_cstar_target); -} - #else /* CONFIG_X86_32 */ #define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SEP)) #define vdso32_syscall() (0) -void enable_sep_cpu(void) -{ - int cpu = get_cpu(); - struct tss_struct *tss = &per_cpu(init_tss, cpu); - - if (!boot_cpu_has(X86_FEATURE_SEP)) { - put_cpu(); - return; - } - - tss->x86_tss.ss1 = __KERNEL_CS; - tss->x86_tss.sp1 = sizeof(struct tss_struct) + (unsigned long) tss; - wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0); - wrmsr(MSR_IA32_SYSENTER_ESP, tss->x86_tss.sp1, 0); - wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long) ia32_sysenter_target, 0); - put_cpu(); -} - #endif /* CONFIG_X86_64 */ +#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT) +const struct vdso_image *selected_vdso32; +#endif + int __init sysenter_setup(void) { - char *vdso32_start, *vdso32_end; - int npages, i; - #ifdef CONFIG_COMPAT - if (vdso32_syscall()) { - vdso32_start = vdso32_syscall_start; - vdso32_end = vdso32_syscall_end; - vdso32_pages = vdso32_syscall_pages; - } else + if (vdso32_syscall()) + selected_vdso32 = &vdso_image_32_syscall; + else #endif - if (vdso32_sysenter()) { - vdso32_start = vdso32_sysenter_start; - vdso32_end = vdso32_sysenter_end; - vdso32_pages = vdso32_sysenter_pages; - } else { - vdso32_start = vdso32_int80_start; - vdso32_end = vdso32_int80_end; - vdso32_pages = vdso32_int80_pages; - } - - 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); + if (vdso32_sysenter()) + selected_vdso32 = &vdso_image_32_sysenter; + else + selected_vdso32 = &vdso_image_32_int80; - patch_vdso32(vdso32_start, vdso32_size); + init_vdso_image(selected_vdso32); return 0; } -/* Setup a VMA at program startup for the vsyscall page */ -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)) - return x32_setup_additional_pages(bprm, uses_interp); -#endif - - if (vdso_enabled != 1) /* Other values all mean "disabled" */ - return 0; - - down_write(&mm->mmap_sem); - - 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); - - current->mm->context.vdso = (void *)addr; - - /* - * 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; - } - - 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); - - up_fail: - if (ret) - current->mm->context.vdso = NULL; - - up_write(&mm->mmap_sem); - - return ret; -} - #ifdef CONFIG_X86_64 subsys_initcall(sysenter_setup); @@ -244,7 +92,7 @@ subsys_initcall(sysenter_setup); static struct ctl_table abi_table2[] = { { .procname = "vsyscall32", - .data = &sysctl_vsyscall32, + .data = &vdso32_enabled, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec @@ -271,13 +119,6 @@ __initcall(ia32_binfmt_init); #else /* CONFIG_X86_32 */ -const char *arch_vma_name(struct vm_area_struct *vma) -{ - if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso) - return "[vdso]"; - return NULL; -} - struct vm_area_struct *get_gate_vma(struct mm_struct *mm) { return NULL; diff --git a/arch/x86/vdso/vdso32.S b/arch/x86/vdso/vdso32.S deleted file mode 100644 index 018bcd9..0000000 --- a/arch/x86/vdso/vdso32.S +++ /dev/null @@ -1,9 +0,0 @@ -#include <asm/vdso.h> - -DEFINE_VDSO_IMAGE(vdso32_int80, "arch/x86/vdso/vdso32-int80.so") - -#ifdef CONFIG_COMPAT -DEFINE_VDSO_IMAGE(vdso32_syscall, "arch/x86/vdso/vdso32-syscall.so") -#endif - -DEFINE_VDSO_IMAGE(vdso32_sysenter, "arch/x86/vdso/vdso32-sysenter.so") diff --git a/arch/x86/vdso/vdso32/vdso32.lds.S b/arch/x86/vdso/vdso32/vdso32.lds.S index aadb8b9..31056cf 100644 --- a/arch/x86/vdso/vdso32/vdso32.lds.S +++ b/arch/x86/vdso/vdso32/vdso32.lds.S @@ -1,17 +1,14 @@ /* * Linker script for 32-bit vDSO. * We #include the file to define the layout details. - * Here we only choose the prelinked virtual address. * * This file defines the version script giving the user-exported symbols in - * the DSO. We can define local symbols here called VDSO* to make their - * values visible using the asm-x86/vdso.h macros from the kernel proper. + * the DSO. */ #include <asm/page.h> #define BUILD_VDSO32 -#define VDSO_PRELINK 0 #include "../vdso-layout.lds.S" @@ -38,13 +35,3 @@ VERSION local: *; }; } - -/* - * Symbols we define here called VDSO* get their values into vdso32-syms.h. - */ -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 deleted file mode 100644 index f4aa34e..0000000 --- a/arch/x86/vdso/vdsox32.S +++ /dev/null @@ -1,3 +0,0 @@ -#include <asm/vdso.h> - -DEFINE_VDSO_IMAGE(vdsox32, "arch/x86/vdso/vdsox32.so") diff --git a/arch/x86/vdso/vdsox32.lds.S b/arch/x86/vdso/vdsox32.lds.S index 62272aa..46b991b 100644 --- a/arch/x86/vdso/vdsox32.lds.S +++ b/arch/x86/vdso/vdsox32.lds.S @@ -1,14 +1,11 @@ /* * Linker script for x32 vDSO. * We #include the file to define the layout details. - * Here we only choose the prelinked virtual address. * * This file defines the version script giving the user-exported symbols in - * the DSO. We can define local symbols here called VDSO* to make their - * values visible using the asm-x86/vdso.h macros from the kernel proper. + * the DSO. */ -#define VDSO_PRELINK 0 #include "vdso-layout.lds.S" /* @@ -24,5 +21,3 @@ VERSION { local: *; }; } - -VDSOX32_PRELINK = VDSO_PRELINK; diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c index 1ad1026..e1513c4 100644 --- a/arch/x86/vdso/vma.c +++ b/arch/x86/vdso/vma.c @@ -15,115 +15,51 @@ #include <asm/proto.h> #include <asm/vdso.h> #include <asm/page.h> +#include <asm/hpet.h> #if defined(CONFIG_X86_64) -unsigned int __read_mostly vdso_enabled = 1; +unsigned int __read_mostly vdso64_enabled = 1; -DECLARE_VDSO_IMAGE(vdso); extern unsigned short vdso_sync_cpuid; -static unsigned vdso_size; - -#ifdef CONFIG_X86_X32_ABI -DECLARE_VDSO_IMAGE(vdsox32); -static unsigned vdsox32_size; -#endif #endif -#if defined(CONFIG_X86_32) || defined(CONFIG_X86_X32_ABI) || \ - defined(CONFIG_COMPAT) -void __init patch_vdso32(void *vdso, size_t len) +void __init init_vdso_image(const struct vdso_image *image) { - Elf32_Ehdr *hdr = vdso; - Elf32_Shdr *sechdrs, *alt_sec = 0; - char *secstrings; - void *alt_data; int i; + int npages = (image->size) / PAGE_SIZE; - BUG_ON(len < sizeof(Elf32_Ehdr)); - BUG_ON(memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0); - - sechdrs = (void *)hdr + hdr->e_shoff; - secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; - - for (i = 1; i < hdr->e_shnum; i++) { - Elf32_Shdr *shdr = &sechdrs[i]; - if (!strcmp(secstrings + shdr->sh_name, ".altinstructions")) { - alt_sec = shdr; - goto found; - } - } - - /* If we get here, it's probably a bug. */ - pr_warning("patch_vdso32: .altinstructions not found\n"); - return; /* nothing to patch */ + BUG_ON(image->size % PAGE_SIZE != 0); + for (i = 0; i < npages; i++) + image->text_mapping.pages[i] = + virt_to_page(image->data + i*PAGE_SIZE); -found: - alt_data = (void *)hdr + alt_sec->sh_offset; - apply_alternatives(alt_data, alt_data + alt_sec->sh_size); + apply_alternatives((struct alt_instr *)(image->data + image->alt), + (struct alt_instr *)(image->data + image->alt + + image->alt_len)); } -#endif #if defined(CONFIG_X86_64) -static void __init patch_vdso64(void *vdso, size_t len) -{ - Elf64_Ehdr *hdr = vdso; - Elf64_Shdr *sechdrs, *alt_sec = 0; - char *secstrings; - void *alt_data; - int i; - - BUG_ON(len < sizeof(Elf64_Ehdr)); - BUG_ON(memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0); - - sechdrs = (void *)hdr + hdr->e_shoff; - secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; - - for (i = 1; i < hdr->e_shnum; i++) { - Elf64_Shdr *shdr = &sechdrs[i]; - if (!strcmp(secstrings + shdr->sh_name, ".altinstructions")) { - alt_sec = shdr; - goto found; - } - } - - /* If we get here, it's probably a bug. */ - pr_warning("patch_vdso64: .altinstructions not found\n"); - return; /* nothing to patch */ - -found: - alt_data = (void *)hdr + alt_sec->sh_offset; - apply_alternatives(alt_data, alt_data + alt_sec->sh_size); -} - static int __init init_vdso(void) { - int npages = (vdso_end - vdso_start + PAGE_SIZE - 1) / PAGE_SIZE; - int i; - - patch_vdso64(vdso_start, vdso_end - vdso_start); - - vdso_size = npages << PAGE_SHIFT; - for (i = 0; i < npages; i++) - vdso_pages[i] = virt_to_page(vdso_start + i*PAGE_SIZE); + init_vdso_image(&vdso_image_64); #ifdef CONFIG_X86_X32_ABI - 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++) - vdsox32_pages[i] = virt_to_page(vdsox32_start + i*PAGE_SIZE); + init_vdso_image(&vdso_image_x32); #endif return 0; } subsys_initcall(init_vdso); +#endif struct linux_binprm; /* Put the vdso above the (randomized) stack with another randomized offset. This way there is no hole in the middle of address space. To save memory make sure it is still in the same PTE as the stack top. - This doesn't give that many random bits */ + This doesn't give that many random bits. + + Only used for the 64-bit and x32 vdsos. */ static unsigned long vdso_addr(unsigned long start, unsigned len) { unsigned long addr, end; @@ -149,61 +85,149 @@ static unsigned long vdso_addr(unsigned long start, unsigned len) return addr; } -/* Setup a VMA at program startup for the vsyscall page. - Not called for compat tasks */ -static int setup_additional_pages(struct linux_binprm *bprm, - int uses_interp, - struct page **pages, - unsigned size) +static int map_vdso(const struct vdso_image *image, bool calculate_addr) { struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; unsigned long addr; - int ret; - - if (!vdso_enabled) - return 0; + int ret = 0; + static struct page *no_pages[] = {NULL}; + static struct vm_special_mapping vvar_mapping = { + .name = "[vvar]", + .pages = no_pages, + }; + + if (calculate_addr) { + addr = vdso_addr(current->mm->start_stack, + image->sym_end_mapping); + } else { + addr = 0; + } down_write(&mm->mmap_sem); - addr = vdso_addr(mm->start_stack, size); - addr = get_unmapped_area(NULL, addr, size, 0, 0); + + addr = get_unmapped_area(NULL, addr, image->sym_end_mapping, 0, 0); if (IS_ERR_VALUE(addr)) { ret = addr; goto up_fail; } - current->mm->context.vdso = (void *)addr; + current->mm->context.vdso = (void __user *)addr; - ret = install_special_mapping(mm, addr, size, - VM_READ|VM_EXEC| - VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, - pages); - if (ret) { - current->mm->context.vdso = NULL; + /* + * MAYWRITE to allow gdb to COW and set breakpoints + */ + vma = _install_special_mapping(mm, + addr, + image->size, + VM_READ|VM_EXEC| + VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, + &image->text_mapping); + + if (IS_ERR(vma)) { + ret = PTR_ERR(vma); goto up_fail; } + vma = _install_special_mapping(mm, + addr + image->size, + image->sym_end_mapping - image->size, + VM_READ, + &vvar_mapping); + + if (IS_ERR(vma)) { + ret = PTR_ERR(vma); + goto up_fail; + } + + if (image->sym_vvar_page) + ret = remap_pfn_range(vma, + addr + image->sym_vvar_page, + __pa_symbol(&__vvar_page) >> PAGE_SHIFT, + PAGE_SIZE, + PAGE_READONLY); + + if (ret) + goto up_fail; + +#ifdef CONFIG_HPET_TIMER + if (hpet_address && image->sym_hpet_page) { + ret = io_remap_pfn_range(vma, + addr + image->sym_hpet_page, + hpet_address >> PAGE_SHIFT, + PAGE_SIZE, + pgprot_noncached(PAGE_READONLY)); + + if (ret) + goto up_fail; + } +#endif + up_fail: + if (ret) + current->mm->context.vdso = NULL; + up_write(&mm->mmap_sem); return ret; } +#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT) +static int load_vdso32(void) +{ + int ret; + + if (vdso32_enabled != 1) /* Other values all mean "disabled" */ + return 0; + + ret = map_vdso(selected_vdso32, false); + if (ret) + return ret; + + if (selected_vdso32->sym_VDSO32_SYSENTER_RETURN) + current_thread_info()->sysenter_return = + current->mm->context.vdso + + selected_vdso32->sym_VDSO32_SYSENTER_RETURN; + + return 0; +} +#endif + +#ifdef CONFIG_X86_64 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) { - return setup_additional_pages(bprm, uses_interp, vdso_pages, - vdso_size); + if (!vdso64_enabled) + return 0; + + return map_vdso(&vdso_image_64, true); } +#ifdef CONFIG_COMPAT +int compat_arch_setup_additional_pages(struct linux_binprm *bprm, + int uses_interp) +{ #ifdef CONFIG_X86_X32_ABI -int x32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) + if (test_thread_flag(TIF_X32)) { + if (!vdso64_enabled) + return 0; + + return map_vdso(&vdso_image_x32, true); + } +#endif + + return load_vdso32(); +} +#endif +#else +int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) { - return setup_additional_pages(bprm, uses_interp, vdsox32_pages, - vdsox32_size); + return load_vdso32(); } #endif +#ifdef CONFIG_X86_64 static __init int vdso_setup(char *s) { - vdso_enabled = simple_strtoul(s, NULL, 0); + vdso64_enabled = simple_strtoul(s, NULL, 0); return 0; } __setup("vdso=", vdso_setup); |