diff options
Diffstat (limited to 'linux-user/elfload.c')
| -rw-r--r-- | linux-user/elfload.c | 357 |
1 files changed, 227 insertions, 130 deletions
diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 2e3809f03c..8761f9e26b 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -23,6 +23,10 @@ #include "target_signal.h" #include "accel/tcg/debuginfo.h" +#ifdef TARGET_ARM +#include "target/arm/cpu-features.h" +#endif + #ifdef _ARCH_PPC64 #undef ARCH_DLINFO #undef ELF_PLATFORM @@ -33,6 +37,19 @@ #undef ELF_ARCH #endif +#ifndef TARGET_ARCH_HAS_SIGTRAMP_PAGE +#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 0 +#endif + +typedef struct { + const uint8_t *image; + const uint32_t *relocs; + unsigned image_size; + unsigned reloc_count; + unsigned sigreturn_ofs; + unsigned rt_sigreturn_ofs; +} VdsoImageInfo; + #define ELF_OSABI ELFOSABI_SYSV /* from personality.h */ @@ -292,12 +309,27 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, const CPUX86State *en (*regs)[15] = tswapreg(env->regs[R_ESP]); (*regs)[16] = tswapreg(env->segs[R_SS].selector & 0xffff); } -#endif + +/* + * i386 is the only target which supplies AT_SYSINFO for the vdso. + * All others only supply AT_SYSINFO_EHDR. + */ +#define DLINFO_ARCH_ITEMS (vdso_info != NULL) +#define ARCH_DLINFO \ + do { \ + if (vdso_info) { \ + NEW_AUX_ENT(AT_SYSINFO, vdso_info->entry); \ + } \ + } while (0) + +#endif /* TARGET_X86_64 */ + +#define VDSO_HEADER "vdso.c.inc" #define USE_ELF_CORE_DUMP #define ELF_EXEC_PAGESIZE 4096 -#endif +#endif /* TARGET_I386 */ #ifdef TARGET_ARM @@ -917,6 +949,13 @@ const char *elf_hwcap2_str(uint32_t bit) #undef GET_FEATURE_ID #endif /* not TARGET_AARCH64 */ + +#if TARGET_BIG_ENDIAN +# define VDSO_HEADER "vdso-be.c.inc" +#else +# define VDSO_HEADER "vdso-le.c.inc" +#endif + #endif /* TARGET_ARM */ #ifdef TARGET_SPARC @@ -1152,6 +1191,14 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, const CPUPPCState *en #define USE_ELF_CORE_DUMP #define ELF_EXEC_PAGESIZE 4096 +#ifndef TARGET_PPC64 +# define VDSO_HEADER "vdso-32.c.inc" +#elif TARGET_BIG_ENDIAN +# define VDSO_HEADER "vdso-64.c.inc" +#else +# define VDSO_HEADER "vdso-64le.c.inc" +#endif + #endif #ifdef TARGET_LOONGARCH64 @@ -1162,6 +1209,8 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, const CPUPPCState *en #define elf_check_arch(x) ((x) == EM_LOONGARCH) +#define VDSO_HEADER "vdso.c.inc" + static inline void init_thread(struct target_pt_regs *regs, struct image_info *infop) { @@ -1849,6 +1898,8 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, #define USE_ELF_CORE_DUMP #define ELF_EXEC_PAGESIZE 4096 +#define VDSO_HEADER "vdso.c.inc" + #endif /* TARGET_S390X */ #ifdef TARGET_RISCV @@ -1857,8 +1908,10 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, #ifdef TARGET_RISCV32 #define ELF_CLASS ELFCLASS32 +#define VDSO_HEADER "vdso-32.c.inc" #else #define ELF_CLASS ELFCLASS64 +#define VDSO_HEADER "vdso-64.c.inc" #endif #define ELF_HWCAP get_elf_hwcap() @@ -1894,6 +1947,8 @@ static inline void init_thread(struct target_pt_regs *regs, #define STACK_GROWS_DOWN 0 #define STACK_ALIGNMENT 64 +#define VDSO_HEADER "vdso.c.inc" + static inline void init_thread(struct target_pt_regs *regs, struct image_info *infop) { @@ -2201,7 +2256,8 @@ static inline void bswap_mips_abiflags(Mips_elf_abiflags_v0 *abiflags) { } #ifdef USE_ELF_CORE_DUMP static int elf_core_dump(int, const CPUArchState *); #endif /* USE_ELF_CORE_DUMP */ -static void load_symbols(struct elfhdr *hdr, int fd, abi_ulong load_bias); +static void load_symbols(struct elfhdr *hdr, const ImageSource *src, + abi_ulong load_bias); /* Verify the portions of EHDR within E_IDENT for the target. This can be performed before bswapping the entire header. */ @@ -2470,7 +2526,8 @@ static abi_ulong loader_build_fdpic_loadmap(struct image_info *info, abi_ulong s static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc, struct elfhdr *exec, struct image_info *info, - struct image_info *interp_info) + struct image_info *interp_info, + struct image_info *vdso_info) { abi_ulong sp; abi_ulong u_argc, u_argv, u_envp, u_auxv; @@ -2558,10 +2615,15 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc, } size = (DLINFO_ITEMS + 1) * 2; - if (k_base_platform) + if (k_base_platform) { size += 2; - if (k_platform) + } + if (k_platform) { size += 2; + } + if (vdso_info) { + size += 2; + } #ifdef DLINFO_ARCH_ITEMS size += DLINFO_ARCH_ITEMS * 2; #endif @@ -2643,6 +2705,9 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc, if (u_platform) { NEW_AUX_ENT(AT_PLATFORM, u_platform); } + if (vdso_info) { + NEW_AUX_ENT(AT_SYSINFO_EHDR, vdso_info->load_addr); + } NEW_AUX_ENT (AT_NULL, 0); #undef NEW_AUX_ENT @@ -3102,10 +3167,9 @@ static bool parse_elf_property(const uint32_t *data, int *off, int datasz, } /* Process NT_GNU_PROPERTY_TYPE_0. */ -static bool parse_elf_properties(int image_fd, +static bool parse_elf_properties(const ImageSource *src, struct image_info *info, const struct elf_phdr *phdr, - char bprm_buf[BPRM_BUF_SIZE], Error **errp) { union { @@ -3133,14 +3197,8 @@ static bool parse_elf_properties(int image_fd, return false; } - if (phdr->p_offset + n <= BPRM_BUF_SIZE) { - memcpy(¬e, bprm_buf + phdr->p_offset, n); - } else { - ssize_t len = pread(image_fd, ¬e, n, phdr->p_offset); - if (len != n) { - error_setg_errno(errp, errno, "Error reading file header"); - return false; - } + if (!imgsrc_read(¬e, phdr->p_offset, n, src, errp)) { + return false; } /* @@ -3186,29 +3244,34 @@ static bool parse_elf_properties(int image_fd, } } -/* Load an ELF image into the address space. - - IMAGE_NAME is the filename of the image, to use in error messages. - IMAGE_FD is the open file descriptor for the image. - - BPRM_BUF is a copy of the beginning of the file; this of course - contains the elf file header at offset 0. It is assumed that this - buffer is sufficiently aligned to present no problems to the host - in accessing data at aligned offsets within the buffer. - - On return: INFO values will be filled in, as necessary or available. */ +/** + * load_elf_image: Load an ELF image into the address space. + * @image_name: the filename of the image, to use in error messages. + * @src: the ImageSource from which to read. + * @info: info collected from the loaded image. + * @ehdr: the ELF header, not yet bswapped. + * @pinterp_name: record any PT_INTERP string found. + * + * On return: @info values will be filled in, as necessary or available. + */ -static void load_elf_image(const char *image_name, int image_fd, - struct image_info *info, char **pinterp_name, - char bprm_buf[BPRM_BUF_SIZE]) +static void load_elf_image(const char *image_name, const ImageSource *src, + struct image_info *info, struct elfhdr *ehdr, + char **pinterp_name) { - struct elfhdr *ehdr = (struct elfhdr *)bprm_buf; - struct elf_phdr *phdr; + g_autofree struct elf_phdr *phdr = NULL; abi_ulong load_addr, load_bias, loaddr, hiaddr, error; - int i, retval, prot_exec; + int i, prot_exec; Error *err = NULL; - /* First of all, some simple consistency checks */ + /* + * First of all, some simple consistency checks. + * Note that we rely on the bswapped ehdr staying in bprm_buf, + * for later use by load_elf_binary and create_elf_tables. + */ + if (!imgsrc_read(ehdr, 0, sizeof(*ehdr), src, &err)) { + goto exit_errmsg; + } if (!elf_check_ident(ehdr)) { error_setg(&err, "Invalid ELF image for this architecture"); goto exit_errmsg; @@ -3219,15 +3282,11 @@ static void load_elf_image(const char *image_name, int image_fd, goto exit_errmsg; } - i = ehdr->e_phnum * sizeof(struct elf_phdr); - if (ehdr->e_phoff + i <= BPRM_BUF_SIZE) { - phdr = (struct elf_phdr *)(bprm_buf + ehdr->e_phoff); - } else { - phdr = (struct elf_phdr *) alloca(i); - retval = pread(image_fd, phdr, i, ehdr->e_phoff); - if (retval != i) { - goto exit_read; - } + phdr = imgsrc_read_alloc(ehdr->e_phoff, + ehdr->e_phnum * sizeof(struct elf_phdr), + src, &err); + if (phdr == NULL) { + goto exit_errmsg; } bswap_phdr(phdr, ehdr->e_phnum); @@ -3264,17 +3323,10 @@ static void load_elf_image(const char *image_name, int image_fd, goto exit_errmsg; } - interp_name = g_malloc(eppnt->p_filesz); - - if (eppnt->p_offset + eppnt->p_filesz <= BPRM_BUF_SIZE) { - memcpy(interp_name, bprm_buf + eppnt->p_offset, - eppnt->p_filesz); - } else { - retval = pread(image_fd, interp_name, eppnt->p_filesz, - eppnt->p_offset); - if (retval != eppnt->p_filesz) { - goto exit_read; - } + interp_name = imgsrc_read_alloc(eppnt->p_offset, eppnt->p_filesz, + src, &err); + if (interp_name == NULL) { + goto exit_errmsg; } if (interp_name[eppnt->p_filesz - 1] != 0) { error_setg(&err, "Invalid PT_INTERP entry"); @@ -3282,7 +3334,7 @@ static void load_elf_image(const char *image_name, int image_fd, } *pinterp_name = g_steal_pointer(&interp_name); } else if (eppnt->p_type == PT_GNU_PROPERTY) { - if (!parse_elf_properties(image_fd, info, eppnt, bprm_buf, &err)) { + if (!parse_elf_properties(src, info, eppnt, &err)) { goto exit_errmsg; } } else if (eppnt->p_type == PT_GNU_STACK) { @@ -3435,9 +3487,9 @@ static void load_elf_image(const char *image_name, int image_fd, * but no backing file segment. */ if (eppnt->p_filesz != 0) { - error = target_mmap(vaddr_ps, eppnt->p_filesz + vaddr_po, + error = imgsrc_mmap(vaddr_ps, eppnt->p_filesz + vaddr_po, elf_prot, MAP_PRIVATE | MAP_FIXED, - image_fd, eppnt->p_offset - vaddr_po); + src, eppnt->p_offset - vaddr_po); if (error == -1) { goto exit_mmap; } @@ -3469,20 +3521,11 @@ static void load_elf_image(const char *image_name, int image_fd, #ifdef TARGET_MIPS } else if (eppnt->p_type == PT_MIPS_ABIFLAGS) { Mips_elf_abiflags_v0 abiflags; - if (eppnt->p_filesz < sizeof(Mips_elf_abiflags_v0)) { - error_setg(&err, "Invalid PT_MIPS_ABIFLAGS entry"); + + if (!imgsrc_read(&abiflags, eppnt->p_offset, sizeof(abiflags), + src, &err)) { goto exit_errmsg; } - if (eppnt->p_offset + eppnt->p_filesz <= BPRM_BUF_SIZE) { - memcpy(&abiflags, bprm_buf + eppnt->p_offset, - sizeof(Mips_elf_abiflags_v0)); - } else { - retval = pread(image_fd, &abiflags, sizeof(Mips_elf_abiflags_v0), - eppnt->p_offset); - if (retval != sizeof(Mips_elf_abiflags_v0)) { - goto exit_read; - } - } bswap_mips_abiflags(&abiflags); info->fp_abi = abiflags.fp_abi; #endif @@ -3495,23 +3538,16 @@ static void load_elf_image(const char *image_name, int image_fd, } if (qemu_log_enabled()) { - load_symbols(ehdr, image_fd, load_bias); + load_symbols(ehdr, src, load_bias); } - debuginfo_report_elf(image_name, image_fd, load_bias); + debuginfo_report_elf(image_name, src->fd, load_bias); mmap_unlock(); - close(image_fd); + close(src->fd); return; - exit_read: - if (retval >= 0) { - error_setg(&err, "Incomplete read of file header"); - } else { - error_setg_errno(&err, errno, "Error reading file header"); - } - goto exit_errmsg; exit_mmap: error_setg_errno(&err, errno, "Error mapping file"); goto exit_errmsg; @@ -3523,6 +3559,8 @@ static void load_elf_image(const char *image_name, int image_fd, static void load_elf_interp(const char *filename, struct image_info *info, char bprm_buf[BPRM_BUF_SIZE]) { + struct elfhdr ehdr; + ImageSource src; int fd, retval; Error *err = NULL; @@ -3540,11 +3578,57 @@ static void load_elf_interp(const char *filename, struct image_info *info, exit(-1); } - if (retval < BPRM_BUF_SIZE) { - memset(bprm_buf + retval, 0, BPRM_BUF_SIZE - retval); + src.fd = fd; + src.cache = bprm_buf; + src.cache_size = retval; + + load_elf_image(filename, &src, info, &ehdr, NULL); +} + +#ifdef VDSO_HEADER +#include VDSO_HEADER +#define vdso_image_info() &vdso_image_info +#else +#define vdso_image_info() NULL +#endif + +static void load_elf_vdso(struct image_info *info, const VdsoImageInfo *vdso) +{ + ImageSource src; + struct elfhdr ehdr; + abi_ulong load_bias, load_addr; + + src.fd = -1; + src.cache = vdso->image; + src.cache_size = vdso->image_size; + + load_elf_image("<internal-vdso>", &src, info, &ehdr, NULL); + load_addr = info->load_addr; + load_bias = info->load_bias; + + /* + * We need to relocate the VDSO image. The one built into the kernel + * is built for a fixed address. The one built for QEMU is not, since + * that requires close control of the guest address space. + * We pre-processed the image to locate all of the addresses that need + * to be updated. + */ + for (unsigned i = 0, n = vdso->reloc_count; i < n; i++) { + abi_ulong *addr = g2h_untagged(load_addr + vdso->relocs[i]); + *addr = tswapal(tswapal(*addr) + load_bias); } - load_elf_image(filename, fd, info, NULL, bprm_buf); + /* Install signal trampolines, if present. */ + if (vdso->sigreturn_ofs) { + default_sigreturn = load_addr + vdso->sigreturn_ofs; + } + if (vdso->rt_sigreturn_ofs) { + default_rt_sigreturn = load_addr + vdso->rt_sigreturn_ofs; + } + + /* Remove write from VDSO segment. */ + target_mprotect(info->start_data, info->end_data - info->start_data, + PROT_READ | PROT_EXEC); } static int symfind(const void *s0, const void *s1) @@ -3591,19 +3675,20 @@ static int symcmp(const void *s0, const void *s1) } /* Best attempt to load symbols from this ELF object. */ -static void load_symbols(struct elfhdr *hdr, int fd, abi_ulong load_bias) +static void load_symbols(struct elfhdr *hdr, const ImageSource *src, + abi_ulong load_bias) { int i, shnum, nsyms, sym_idx = 0, str_idx = 0; - uint64_t segsz; - struct elf_shdr *shdr; + g_autofree struct elf_shdr *shdr = NULL; char *strings = NULL; - struct syminfo *s = NULL; - struct elf_sym *new_syms, *syms = NULL; + struct elf_sym *syms = NULL; + struct elf_sym *new_syms; + uint64_t segsz; shnum = hdr->e_shnum; - i = shnum * sizeof(struct elf_shdr); - shdr = (struct elf_shdr *)alloca(i); - if (pread(fd, shdr, i, hdr->e_shoff) != i) { + shdr = imgsrc_read_alloc(hdr->e_shoff, shnum * sizeof(struct elf_shdr), + src, NULL); + if (shdr == NULL) { return; } @@ -3621,31 +3706,33 @@ static void load_symbols(struct elfhdr *hdr, int fd, abi_ulong load_bias) found: /* Now know where the strtab and symtab are. Snarf them. */ - s = g_try_new(struct syminfo, 1); - if (!s) { - goto give_up; - } segsz = shdr[str_idx].sh_size; - s->disas_strtab = strings = g_try_malloc(segsz); - if (!strings || - pread(fd, strings, segsz, shdr[str_idx].sh_offset) != segsz) { + strings = g_try_malloc(segsz); + if (!strings) { goto give_up; } - - segsz = shdr[sym_idx].sh_size; - syms = g_try_malloc(segsz); - if (!syms || pread(fd, syms, segsz, shdr[sym_idx].sh_offset) != segsz) { + if (!imgsrc_read(strings, shdr[str_idx].sh_offset, segsz, src, NULL)) { goto give_up; } + segsz = shdr[sym_idx].sh_size; if (segsz / sizeof(struct elf_sym) > INT_MAX) { - /* Implausibly large symbol table: give up rather than ploughing - * on with the number of symbols calculation overflowing + /* + * Implausibly large symbol table: give up rather than ploughing + * on with the number of symbols calculation overflowing. */ goto give_up; } nsyms = segsz / sizeof(struct elf_sym); + syms = g_try_malloc(segsz); + if (!syms) { + goto give_up; + } + if (!imgsrc_read(syms, shdr[sym_idx].sh_offset, segsz, src, NULL)) { + goto give_up; + } + for (i = 0; i < nsyms; ) { bswap_sym(syms + i); /* Throw away entries which we do not need. */ @@ -3670,10 +3757,12 @@ static void load_symbols(struct elfhdr *hdr, int fd, abi_ulong load_bias) goto give_up; } - /* Attempt to free the storage associated with the local symbols - that we threw away. Whether or not this has any effect on the - memory allocation depends on the malloc implementation and how - many symbols we managed to discard. */ + /* + * Attempt to free the storage associated with the local symbols + * that we threw away. Whether or not this has any effect on the + * memory allocation depends on the malloc implementation and how + * many symbols we managed to discard. + */ new_syms = g_try_renew(struct elf_sym, syms, nsyms); if (new_syms == NULL) { goto give_up; @@ -3682,20 +3771,23 @@ static void load_symbols(struct elfhdr *hdr, int fd, abi_ulong load_bias) qsort(syms, nsyms, sizeof(*syms), symcmp); - s->disas_num_syms = nsyms; + { + struct syminfo *s = g_new(struct syminfo, 1); + + s->disas_strtab = strings; + s->disas_num_syms = nsyms; #if ELF_CLASS == ELFCLASS32 - s->disas_symtab.elf32 = syms; + s->disas_symtab.elf32 = syms; #else - s->disas_symtab.elf64 = syms; + s->disas_symtab.elf64 = syms; #endif - s->lookup_symbol = lookup_symbolxx; - s->next = syminfos; - syminfos = s; - + s->lookup_symbol = lookup_symbolxx; + s->next = syminfos; + syminfos = s; + } return; -give_up: - g_free(s); + give_up: g_free(strings); g_free(syms); } @@ -3737,8 +3829,14 @@ uint32_t get_elf_eflags(int fd) int load_elf_binary(struct linux_binprm *bprm, struct image_info *info) { - struct image_info interp_info; - struct elfhdr elf_ex; + /* + * We need a copy of the elf header for passing to create_elf_tables. + * We will have overwritten the original when we re-use bprm->buf + * while loading the interpreter. Allocate the storage for this now + * and let elf_load_image do any swapping that may be required. + */ + struct elfhdr ehdr; + struct image_info interp_info, vdso_info; char *elf_interpreter = NULL; char *scratch; @@ -3747,13 +3845,7 @@ int load_elf_binary(struct linux_binprm *bprm, struct image_info *info) interp_info.fp_abi = MIPS_ABI_FP_UNKNOWN; #endif - load_elf_image(bprm->filename, bprm->fd, info, - &elf_interpreter, bprm->buf); - - /* ??? We need a copy of the elf header for passing to create_elf_tables. - If we do nothing, we'll have overwritten this when we re-use bprm->buf - when we load the interpreter. */ - elf_ex = *(struct elfhdr *)bprm->buf; + load_elf_image(bprm->filename, &bprm->src, info, &ehdr, &elf_interpreter); /* Do this so that we can load the interpreter, if need be. We will change some of these later */ @@ -3825,10 +3917,14 @@ int load_elf_binary(struct linux_binprm *bprm, struct image_info *info) } /* - * TODO: load a vdso, which would also contain the signal trampolines. - * Otherwise, allocate a private page to hold them. + * Load a vdso if available, which will amongst other things contain the + * signal trampolines. Otherwise, allocate a separate page for them. */ - if (TARGET_ARCH_HAS_SIGTRAMP_PAGE) { + const VdsoImageInfo *vdso = vdso_image_info(); + if (vdso) { + load_elf_vdso(&vdso_info, vdso); + info->vdso = vdso_info.load_bias; + } else if (TARGET_ARCH_HAS_SIGTRAMP_PAGE) { abi_long tramp_page = target_mmap(0, TARGET_PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); @@ -3840,8 +3936,9 @@ int load_elf_binary(struct linux_binprm *bprm, struct image_info *info) target_mprotect(tramp_page, TARGET_PAGE_SIZE, PROT_READ | PROT_EXEC); } - bprm->p = create_elf_tables(bprm->p, bprm->argc, bprm->envc, &elf_ex, - info, (elf_interpreter ? &interp_info : NULL)); + bprm->p = create_elf_tables(bprm->p, bprm->argc, bprm->envc, &ehdr, info, + elf_interpreter ? &interp_info : NULL, + vdso ? &vdso_info : NULL); info->start_stack = bprm->p; /* If we have an interpreter, set that as the program's entry point. |