X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fbinfmt_flat.c;h=e92f229e3c6e9d994d61f5581625c35c2bde6bd7;hb=7d217caca5d704e48aa5e59aba0b3ad4c7af4fd2;hp=33764fd6db66122ff36b52fba3ebf95f26d4a5d7;hpb=0e647c04f665e9b3451a1ebe8252b38ffe0207c8;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index 33764fd..e92f229 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -20,7 +20,6 @@ #include #include #include -#include #include #include #include @@ -42,6 +41,7 @@ #include #include #include +#include /****************************************************************************/ @@ -55,6 +55,18 @@ #define DBG_FLT(a...) #endif +/* + * User data (stack, data section and bss) needs to be aligned + * for the same reasons as SLAB memory is, and to the same amount. + * Avoid duplicating architecture specific code by using the same + * macro as with SLAB allocation: + */ +#ifdef ARCH_SLAB_MINALIGN +#define FLAT_DATA_ALIGN (ARCH_SLAB_MINALIGN) +#else +#define FLAT_DATA_ALIGN (sizeof(void *)) +#endif + #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */ #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */ @@ -115,20 +127,18 @@ static unsigned long create_flat_tables( int envc = bprm->envc; char uninitialized_var(dummy); - sp = (unsigned long *) ((-(unsigned long)sizeof(char *))&(unsigned long) p); - - sp -= envc+1; - envp = sp; - sp -= argc+1; - argv = sp; + sp = (unsigned long *)p; + sp -= (envc + argc + 2) + 1 + (flat_argvp_envp_on_stack() ? 2 : 0); + sp = (unsigned long *) ((unsigned long)sp & -FLAT_DATA_ALIGN); + argv = sp + 1 + (flat_argvp_envp_on_stack() ? 2 : 0); + envp = argv + (argc + 1); - flat_stack_align(sp); if (flat_argvp_envp_on_stack()) { - --sp; put_user((unsigned long) envp, sp); - --sp; put_user((unsigned long) argv, sp); + put_user((unsigned long) envp, sp + 2); + put_user((unsigned long) argv, sp + 1); } - put_user(argc,--sp); + put_user(argc, sp); current->mm->arg_start = (unsigned long) p; while (argc-->0) { put_user((unsigned long) p, argv++); @@ -230,13 +240,13 @@ static int decompress_exec( ret = 10; if (buf[3] & EXTRA_FIELD) { ret += 2 + buf[10] + (buf[11] << 8); - if (unlikely(LBUFSIZE == ret)) { + if (unlikely(LBUFSIZE <= ret)) { DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n"); goto out_free_buf; } } if (buf[3] & ORIG_NAME) { - for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) + while (ret < LBUFSIZE && buf[ret++] != 0) ; if (unlikely(LBUFSIZE == ret)) { DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n"); @@ -244,7 +254,7 @@ static int decompress_exec( } } if (buf[3] & COMMENT) { - for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) + while (ret < LBUFSIZE && buf[ret++] != 0) ; if (unlikely(LBUFSIZE == ret)) { DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n"); @@ -418,8 +428,8 @@ static int load_flat_file(struct linux_binprm * bprm, unsigned long textpos = 0, datapos = 0, result; unsigned long realdatastart = 0; unsigned long text_len, data_len, bss_len, stack_len, flags; - unsigned long len, reallen, memp = 0; - unsigned long extra, rlim; + unsigned long len, memp = 0; + unsigned long memp_size, extra, rlim; unsigned long *reloc = 0, *rp; struct inode *inode; int i, rev, relocs = 0; @@ -444,12 +454,12 @@ static int load_flat_file(struct linux_binprm * bprm, if (strncmp(hdr->magic, "bFLT", 4)) { /* + * Previously, here was a printk to tell people + * "BINFMT_FLAT: bad header magic". + * But for the kernel which also use ELF FD-PIC format, this + * error message is confusing. * because a lot of people do not manage to produce good - * flat binaries, we leave this printk to help them realise - * the problem. We only print the error if its not a script file */ - if (strncmp(hdr->magic, "#!", 2)) - printk("BINFMT_FLAT: bad header magic\n"); ret = -ENOEXEC; goto err; } @@ -532,7 +542,8 @@ static int load_flat_file(struct linux_binprm * bprm, DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n"); down_write(¤t->mm->mmap_sem); - textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, MAP_PRIVATE, 0); + textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, + MAP_PRIVATE|MAP_EXECUTABLE, 0); up_write(¤t->mm->mmap_sem); if (!textpos || textpos >= (unsigned long) -4096) { if (!textpos) @@ -543,17 +554,10 @@ static int load_flat_file(struct linux_binprm * bprm, } len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); + len = PAGE_ALIGN(len); down_write(¤t->mm->mmap_sem); realdatastart = do_mmap(0, 0, len, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); - /* Remap to use all availabe slack region space */ - if (realdatastart && (realdatastart < (unsigned long)-4096)) { - reallen = ksize((void *)realdatastart); - if (reallen > len) { - realdatastart = do_mremap(realdatastart, len, - reallen, MREMAP_FIXED, realdatastart); - } - } up_write(¤t->mm->mmap_sem); if (realdatastart == 0 || realdatastart >= (unsigned long)-4096) { @@ -565,7 +569,9 @@ static int load_flat_file(struct linux_binprm * bprm, ret = realdatastart; goto err; } - datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long); + datapos = ALIGN(realdatastart + + MAX_SHARED_LIBS * sizeof(unsigned long), + FLAT_DATA_ALIGN); DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n", (int)(data_len + bss_len + stack_len), (int)datapos); @@ -591,21 +597,14 @@ static int load_flat_file(struct linux_binprm * bprm, reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len)); memp = realdatastart; - + memp_size = len; } else { len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); + len = PAGE_ALIGN(len); down_write(¤t->mm->mmap_sem); textpos = do_mmap(0, 0, len, PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); - /* Remap to use all availabe slack region space */ - if (textpos && (textpos < (unsigned long) -4096)) { - reallen = ksize((void *)textpos); - if (reallen > len) { - textpos = do_mremap(textpos, len, reallen, - MREMAP_FIXED, textpos); - } - } up_write(¤t->mm->mmap_sem); if (!textpos || textpos >= (unsigned long) -4096) { @@ -618,11 +617,14 @@ static int load_flat_file(struct linux_binprm * bprm, } realdatastart = textpos + ntohl(hdr->data_start); - datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long); - reloc = (unsigned long *) (textpos + ntohl(hdr->reloc_start) + - MAX_SHARED_LIBS * sizeof(unsigned long)); - memp = textpos; + datapos = ALIGN(realdatastart + + MAX_SHARED_LIBS * sizeof(unsigned long), + FLAT_DATA_ALIGN); + reloc = (unsigned long *) + (datapos + (ntohl(hdr->reloc_start) - text_len)); + memp = textpos; + memp_size = len; #ifdef CONFIG_BINFMT_ZFLAT /* * load it all in and treat it like a RAM load from now on @@ -680,10 +682,12 @@ static int load_flat_file(struct linux_binprm * bprm, * set up the brk stuff, uses any slack left in data/bss/stack * allocation. We put the brk after the bss (between the bss * and stack) like other platforms. + * Userspace code relies on the stack pointer starting out at + * an address right at the end of a page. */ current->mm->start_brk = datapos + data_len + bss_len; current->mm->brk = (current->mm->start_brk + 3) & ~3; - current->mm->context.end_brk = memp + ksize((void *) memp) - stack_len; + current->mm->context.end_brk = memp + memp_size - stack_len; } if (flags & FLAT_FLAG_KTRACE) @@ -790,8 +794,8 @@ static int load_flat_file(struct linux_binprm * bprm, /* zero the BSS, BRK and stack areas */ memset((void*)(datapos + data_len), 0, bss_len + - (memp + ksize((void *) memp) - stack_len - /* end brk */ - libinfo->lib_list[id].start_brk) + /* start brk */ + (memp + memp_size - stack_len - /* end brk */ + libinfo->lib_list[id].start_brk) + /* start brk */ stack_len); return 0; @@ -824,15 +828,22 @@ static int load_flat_shared_library(int id, struct lib_info *libs) if (IS_ERR(bprm.file)) return res; + bprm.cred = prepare_exec_creds(); + res = -ENOMEM; + if (!bprm.cred) + goto out; + res = prepare_binprm(&bprm); if (res <= (unsigned long)-4096) res = load_flat_file(&bprm, libs, id, NULL); - if (bprm.file) { - allow_write_access(bprm.file); - fput(bprm.file); - bprm.file = NULL; - } + + abort_creds(bprm.cred); + +out: + allow_write_access(bprm.file); + fput(bprm.file); + return(res); } @@ -866,7 +877,7 @@ static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs) stack_len = TOP_OF_ARGS - bprm->p; /* the strings */ stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */ stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */ - + stack_len += FLAT_DATA_ALIGN - 1; /* reserve for upcoming alignment */ res = load_flat_file(bprm, &libinfo, 0, &stack_len); if (res > (unsigned long)-4096) @@ -880,7 +891,7 @@ static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs) (libinfo.lib_list[j].loaded)? libinfo.lib_list[j].start_data:UNLOADED_LIB; - compute_creds(bprm); + install_exec_creds(bprm); current->flags &= ~PF_FORKNOEXEC; set_binfmt(&flat_format); @@ -914,15 +925,14 @@ static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs) /* Stash our initial stack pointer into the mm structure */ current->mm->start_stack = (unsigned long )sp; - +#ifdef FLAT_PLAT_INIT + FLAT_PLAT_INIT(regs); +#endif DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n", (int)regs, (int)start_addr, (int)current->mm->start_stack); start_thread(regs, start_addr, current->mm->start_stack); - if (current->ptrace & PT_PTRACED) - send_sig(SIGTRAP, current, 0); - return 0; } @@ -933,14 +943,8 @@ static int __init init_flat_binfmt(void) return register_binfmt(&flat_format); } -static void __exit exit_flat_binfmt(void) -{ - unregister_binfmt(&flat_format); -} - /****************************************************************************/ core_initcall(init_flat_binfmt); -module_exit(exit_flat_binfmt); /****************************************************************************/