/*--------------------------------------------------------------------*/ /*--- Startup: create initial process image on Linux ---*/ /*--- initimg-linux.c ---*/ /*--------------------------------------------------------------------*/ /* This file is part of Valgrind, a dynamic binary instrumentation framework. Copyright (C) 2000-2012 Julian Seward jseward@acm.org This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA. The GNU General Public License is contained in the file COPYING. */ #if defined(VGO_linux) #include "pub_core_basics.h" #include "pub_core_vki.h" #include "pub_core_debuglog.h" #include "pub_core_libcbase.h" #include "pub_core_libcassert.h" #include "pub_core_libcfile.h" #include "pub_core_libcproc.h" #include "pub_core_libcprint.h" #include "pub_core_xarray.h" #include "pub_core_clientstate.h" #include "pub_core_aspacemgr.h" #include "pub_core_mallocfree.h" #include "pub_core_machine.h" #include "pub_core_ume.h" #include "pub_core_options.h" #include "pub_core_syscall.h" #include "pub_core_tooliface.h" /* VG_TRACK */ #include "pub_core_libcsetjmp.h" // to keep _threadstate.h happy #include "pub_core_threadstate.h" /* ThreadArchState */ #include "priv_initimg_pathscan.h" #include "pub_core_initimg.h" /* self */ /* --- !!! --- EXTERNAL HEADERS start --- !!! --- */ #define _GNU_SOURCE #define _FILE_OFFSET_BITS 64 /* This is for ELF types etc, and also the AT_ constants. */ #include <elf.h> /* --- !!! --- EXTERNAL HEADERS end --- !!! --- */ /*====================================================================*/ /*=== Loading the client ===*/ /*====================================================================*/ /* Load the client whose name is VG_(argv_the_exename). */ static void load_client ( /*OUT*/ExeInfo* info, /*OUT*/Addr* client_ip, /*OUT*/Addr* client_toc) { HChar* exe_name; Int ret; SysRes res; vg_assert( VG_(args_the_exename) != NULL); exe_name = ML_(find_executable)( VG_(args_the_exename) ); if (!exe_name) { VG_(printf)("valgrind: %s: command not found\n", VG_(args_the_exename)); VG_(exit)(127); // 127 is Posix NOTFOUND } VG_(memset)(info, 0, sizeof(*info)); ret = VG_(do_exec)(exe_name, info); if (ret < 0) { VG_(printf)("valgrind: could not execute '%s'\n", exe_name); VG_(exit)(1); } // The client was successfully loaded! Continue. /* Get hold of a file descriptor which refers to the client executable. This is needed for attaching to GDB. */ res = VG_(open)(exe_name, VKI_O_RDONLY, VKI_S_IRUSR); if (!sr_isError(res)) VG_(cl_exec_fd) = sr_Res(res); /* Copy necessary bits of 'info' that were filled in */ *client_ip = info->init_ip; *client_toc = info->init_toc; VG_(brk_base) = VG_(brk_limit) = VG_PGROUNDUP(info->brkbase); } /*====================================================================*/ /*=== Setting up the client's environment ===*/ /*====================================================================*/ /* Prepare the client's environment. This is basically a copy of our environment, except: LD_PRELOAD=$VALGRIND_LIB/vgpreload_core-PLATFORM.so: ($VALGRIND_LIB/vgpreload_TOOL-PLATFORM.so:)? $LD_PRELOAD If this is missing, then it is added. Also, remove any binding for VALGRIND_LAUNCHER=. The client should not be able to see this. If this needs to handle any more variables it should be hacked into something table driven. The copy is VG_(malloc)'d space. */ static HChar** setup_client_env ( HChar** origenv, const HChar* toolname) { HChar* preload_core = "vgpreload_core"; HChar* ld_preload = "LD_PRELOAD="; HChar* v_launcher = VALGRIND_LAUNCHER "="; Int ld_preload_len = VG_(strlen)( ld_preload ); Int v_launcher_len = VG_(strlen)( v_launcher ); Bool ld_preload_done = False; Int vglib_len = VG_(strlen)(VG_(libdir)); Bool debug = False; HChar** cpp; HChar** ret; HChar* preload_tool_path; Int envc, i; /* Alloc space for the vgpreload_core.so path and vgpreload_<tool>.so paths. We might not need the space for vgpreload_<tool>.so, but it doesn't hurt to over-allocate briefly. The 16s are just cautious slop. */ Int preload_core_path_len = vglib_len + sizeof(preload_core) + sizeof(VG_PLATFORM) + 16; Int preload_tool_path_len = vglib_len + VG_(strlen)(toolname) + sizeof(VG_PLATFORM) + 16; Int preload_string_len = preload_core_path_len + preload_tool_path_len; HChar* preload_string = VG_(malloc)("initimg-linux.sce.1", preload_string_len); vg_assert(origenv); vg_assert(toolname); vg_assert(preload_string); /* Determine if there's a vgpreload_<tool>_<platform>.so file, and setup preload_string. */ preload_tool_path = VG_(malloc)("initimg-linux.sce.2", preload_tool_path_len); vg_assert(preload_tool_path); VG_(snprintf)(preload_tool_path, preload_tool_path_len, "%s/vgpreload_%s-%s.so", VG_(libdir), toolname, VG_PLATFORM); if (VG_(access)(preload_tool_path, True/*r*/, False/*w*/, False/*x*/) == 0) { VG_(snprintf)(preload_string, preload_string_len, "%s/%s-%s.so:%s", VG_(libdir), preload_core, VG_PLATFORM, preload_tool_path); } else { VG_(snprintf)(preload_string, preload_string_len, "%s/%s-%s.so", VG_(libdir), preload_core, VG_PLATFORM); } VG_(free)(preload_tool_path); VG_(debugLog)(2, "initimg", "preload_string:\n"); VG_(debugLog)(2, "initimg", " \"%s\"\n", preload_string); /* Count the original size of the env */ if (debug) VG_(printf)("\n\n"); envc = 0; for (cpp = origenv; cpp && *cpp; cpp++) { envc++; if (debug) VG_(printf)("XXXXXXXXX: BEFORE %s\n", *cpp); } /* Allocate a new space */ ret = VG_(malloc) ("initimg-linux.sce.3", sizeof(HChar *) * (envc+1+1)); /* 1 new entry + NULL */ vg_assert(ret); /* copy it over */ for (cpp = ret; *origenv; ) { if (debug) VG_(printf)("XXXXXXXXX: COPY %s\n", *origenv); *cpp++ = *origenv++; } *cpp = NULL; vg_assert(envc == (cpp - ret)); /* Walk over the new environment, mashing as we go */ for (cpp = ret; cpp && *cpp; cpp++) { if (VG_(memcmp)(*cpp, ld_preload, ld_preload_len) == 0) { Int len = VG_(strlen)(*cpp) + preload_string_len; HChar *cp = VG_(malloc)("initimg-linux.sce.4", len); vg_assert(cp); VG_(snprintf)(cp, len, "%s%s:%s", ld_preload, preload_string, (*cpp)+ld_preload_len); *cpp = cp; ld_preload_done = True; } if (debug) VG_(printf)("XXXXXXXXX: MASH %s\n", *cpp); } /* Add the missing bits */ if (!ld_preload_done) { Int len = ld_preload_len + preload_string_len; HChar *cp = VG_(malloc) ("initimg-linux.sce.5", len); vg_assert(cp); VG_(snprintf)(cp, len, "%s%s", ld_preload, preload_string); ret[envc++] = cp; if (debug) VG_(printf)("XXXXXXXXX: ADD %s\n", cp); } /* ret[0 .. envc-1] is live now. */ /* Find and remove a binding for VALGRIND_LAUNCHER. */ for (i = 0; i < envc; i++) if (0 == VG_(memcmp(ret[i], v_launcher, v_launcher_len))) break; if (i < envc) { for (; i < envc-1; i++) ret[i] = ret[i+1]; envc--; } VG_(free)(preload_string); ret[envc] = NULL; for (i = 0; i < envc; i++) { if (debug) VG_(printf)("XXXXXXXXX: FINAL %s\n", ret[i]); } return ret; } /*====================================================================*/ /*=== Setting up the client's stack ===*/ /*====================================================================*/ #ifndef AT_DCACHEBSIZE #define AT_DCACHEBSIZE 19 #endif /* AT_DCACHEBSIZE */ #ifndef AT_ICACHEBSIZE #define AT_ICACHEBSIZE 20 #endif /* AT_ICACHEBSIZE */ #ifndef AT_UCACHEBSIZE #define AT_UCACHEBSIZE 21 #endif /* AT_UCACHEBSIZE */ #ifndef AT_BASE_PLATFORM #define AT_BASE_PLATFORM 24 #endif /* AT_BASE_PLATFORM */ #ifndef AT_RANDOM #define AT_RANDOM 25 #endif /* AT_RANDOM */ #ifndef AT_EXECFN #define AT_EXECFN 31 #endif /* AT_EXECFN */ #ifndef AT_SYSINFO #define AT_SYSINFO 32 #endif /* AT_SYSINFO */ #ifndef AT_SYSINFO_EHDR #define AT_SYSINFO_EHDR 33 #endif /* AT_SYSINFO_EHDR */ #ifndef AT_SECURE #define AT_SECURE 23 /* secure mode boolean */ #endif /* AT_SECURE */ /* Add a string onto the string table, and return its address */ static char *copy_str(char **tab, const char *str) { char *cp = *tab; char *orig = cp; while(*str) *cp++ = *str++; *cp++ = '\0'; if (0) VG_(printf)("copied %p \"%s\" len %lld\n", orig, orig, (Long)(cp-orig)); *tab = cp; return orig; } /* ---------------------------------------------------------------- This sets up the client's initial stack, containing the args, environment and aux vector. The format of the stack is: higher address +-----------------+ <- clstack_end | | : string table : | | +-----------------+ | AT_NULL | - - | auxv | +-----------------+ | NULL | - - | envp | +-----------------+ | NULL | - - | argv | +-----------------+ | argc | lower address +-----------------+ <- sp | undefined | : : Allocate and create the initial client stack. It is allocated down from clstack_end, which was previously determined by the address space manager. The returned value is the SP value for the client. The client's auxv is created by copying and modifying our own one. As a side effect of scanning our own auxv, some important bits of info are collected: VG_(cache_line_size_ppc32) // ppc32 only -- cache line size VG_(have_altivec_ppc32) // ppc32 only -- is Altivec supported? ---------------------------------------------------------------- */ struct auxv { Word a_type; union { void *a_ptr; Word a_val; } u; }; static struct auxv *find_auxv(UWord* sp) { sp++; // skip argc (Nb: is word-sized, not int-sized!) while (*sp != 0) // skip argv sp++; sp++; while (*sp != 0) // skip env sp++; sp++; #if defined(VGA_ppc32) || defined(VGA_ppc64) # if defined AT_IGNOREPPC while (*sp == AT_IGNOREPPC) // skip AT_IGNOREPPC entries sp += 2; # endif #endif return (struct auxv *)sp; } static Addr setup_client_stack( void* init_sp, char** orig_envp, const ExeInfo* info, UInt** client_auxv, Addr clstack_end, SizeT clstack_max_size ) { SysRes res; char **cpp; char *strtab; /* string table */ char *stringbase; Addr *ptr; struct auxv *auxv; const struct auxv *orig_auxv; const struct auxv *cauxv; unsigned stringsize; /* total size of strings in bytes */ unsigned auxsize; /* total size of auxv in bytes */ Int argc; /* total argc */ Int envc; /* total number of env vars */ unsigned stacksize; /* total client stack size */ Addr client_SP; /* client stack base (initial SP) */ Addr clstack_start; Int i; Bool have_exename; vg_assert(VG_IS_PAGE_ALIGNED(clstack_end+1)); vg_assert( VG_(args_for_client) ); /* use our own auxv as a prototype */ orig_auxv = find_auxv(init_sp); /* ==================== compute sizes ==================== */ /* first of all, work out how big the client stack will be */ stringsize = 0; have_exename = VG_(args_the_exename) != NULL; /* paste on the extra args if the loader needs them (ie, the #! interpreter and its argument) */ argc = 0; if (info->interp_name != NULL) { argc++; stringsize += VG_(strlen)(info->interp_name) + 1; } if (info->interp_args != NULL) { argc++; stringsize += VG_(strlen)(info->interp_args) + 1; } /* now scan the args we're given... */ if (have_exename) stringsize += VG_(strlen)( VG_(args_the_exename) ) + 1; for (i = 0; i < VG_(sizeXA)( VG_(args_for_client) ); i++) { argc++; stringsize += VG_(strlen)( * (HChar**) VG_(indexXA)( VG_(args_for_client), i )) + 1; } /* ...and the environment */ envc = 0; for (cpp = orig_envp; cpp && *cpp; cpp++) { envc++; stringsize += VG_(strlen)(*cpp) + 1; } /* now, how big is the auxv? */ auxsize = sizeof(*auxv); /* there's always at least one entry: AT_NULL */ for (cauxv = orig_auxv; cauxv->a_type != AT_NULL; cauxv++) { if (cauxv->a_type == AT_PLATFORM || cauxv->a_type == AT_BASE_PLATFORM) stringsize += VG_(strlen)(cauxv->u.a_ptr) + 1; else if (cauxv->a_type == AT_RANDOM) stringsize += 16; else if (cauxv->a_type == AT_EXECFN && have_exename) stringsize += VG_(strlen)(VG_(args_the_exename)) + 1; auxsize += sizeof(*cauxv); } # if defined(VGP_ppc32_linux) || defined(VGP_ppc64_linux) auxsize += 2 * sizeof(*cauxv); # endif /* OK, now we know how big the client stack is */ stacksize = sizeof(Word) + /* argc */ (have_exename ? sizeof(char **) : 0) + /* argc[0] == exename */ sizeof(char **)*argc + /* argv */ sizeof(char **) + /* terminal NULL */ sizeof(char **)*envc + /* envp */ sizeof(char **) + /* terminal NULL */ auxsize + /* auxv */ VG_ROUNDUP(stringsize, sizeof(Word)); /* strings (aligned) */ if (0) VG_(printf)("stacksize = %d\n", stacksize); /* client_SP is the client's stack pointer */ client_SP = clstack_end - stacksize; client_SP = VG_ROUNDDN(client_SP, 16); /* make stack 16 byte aligned */ /* base of the string table (aligned) */ stringbase = strtab = (char *)clstack_end - VG_ROUNDUP(stringsize, sizeof(int)); clstack_start = VG_PGROUNDDN(client_SP); /* The max stack size */ clstack_max_size = VG_PGROUNDUP(clstack_max_size); /* Record stack extent -- needed for stack-change code. */ VG_(clstk_base) = clstack_start; VG_(clstk_end) = clstack_end; if (0) VG_(printf)("stringsize=%d auxsize=%d stacksize=%d maxsize=0x%x\n" "clstack_start %p\n" "clstack_end %p\n", stringsize, auxsize, stacksize, (Int)clstack_max_size, (void*)clstack_start, (void*)clstack_end); /* ==================== allocate space ==================== */ { SizeT anon_size = clstack_end - clstack_start + 1; SizeT resvn_size = clstack_max_size - anon_size; Addr anon_start = clstack_start; Addr resvn_start = anon_start - resvn_size; SizeT inner_HACK = 0; Bool ok; /* So far we've only accounted for space requirements down to the stack pointer. If this target's ABI requires a redzone below the stack pointer, we need to allocate an extra page, to handle the worst case in which the stack pointer is almost at the bottom of a page, and so there is insufficient room left over to put the redzone in. In this case the simple thing to do is allocate an extra page, by shrinking the reservation by one page and growing the anonymous area by a corresponding page. */ vg_assert(VG_STACK_REDZONE_SZB >= 0); vg_assert(VG_STACK_REDZONE_SZB < VKI_PAGE_SIZE); if (VG_STACK_REDZONE_SZB > 0) { vg_assert(resvn_size > VKI_PAGE_SIZE); resvn_size -= VKI_PAGE_SIZE; anon_start -= VKI_PAGE_SIZE; anon_size += VKI_PAGE_SIZE; } vg_assert(VG_IS_PAGE_ALIGNED(anon_size)); vg_assert(VG_IS_PAGE_ALIGNED(resvn_size)); vg_assert(VG_IS_PAGE_ALIGNED(anon_start)); vg_assert(VG_IS_PAGE_ALIGNED(resvn_start)); vg_assert(resvn_start == clstack_end + 1 - clstack_max_size); # ifdef ENABLE_INNER inner_HACK = 1024*1024; // create 1M non-fault-extending stack # endif if (0) VG_(printf)("%#lx 0x%lx %#lx 0x%lx\n", resvn_start, resvn_size, anon_start, anon_size); /* Create a shrinkable reservation followed by an anonymous segment. Together these constitute a growdown stack. */ res = VG_(mk_SysRes_Error)(0); ok = VG_(am_create_reservation)( resvn_start, resvn_size -inner_HACK, SmUpper, anon_size +inner_HACK ); if (ok) { /* allocate a stack - mmap enough space for the stack */ res = VG_(am_mmap_anon_fixed_client)( anon_start -inner_HACK, anon_size +inner_HACK, VKI_PROT_READ|VKI_PROT_WRITE|VKI_PROT_EXEC ); } if ((!ok) || sr_isError(res)) { /* Allocation of the stack failed. We have to stop. */ VG_(printf)("valgrind: " "I failed to allocate space for the application's stack.\n"); VG_(printf)("valgrind: " "This may be the result of a very large --main-stacksize=\n"); VG_(printf)("valgrind: setting. Cannot continue. Sorry.\n\n"); VG_(exit)(0); } vg_assert(ok); vg_assert(!sr_isError(res)); } /* ==================== create client stack ==================== */ ptr = (Addr*)client_SP; /* --- client argc --- */ *ptr++ = argc + (have_exename ? 1 : 0); /* --- client argv --- */ if (info->interp_name) { *ptr++ = (Addr)copy_str(&strtab, info->interp_name); VG_(free)(info->interp_name); } if (info->interp_args) { *ptr++ = (Addr)copy_str(&strtab, info->interp_args); VG_(free)(info->interp_args); } if (have_exename) *ptr++ = (Addr)copy_str(&strtab, VG_(args_the_exename)); for (i = 0; i < VG_(sizeXA)( VG_(args_for_client) ); i++) { *ptr++ = (Addr)copy_str( &strtab, * (HChar**) VG_(indexXA)( VG_(args_for_client), i ) ); } *ptr++ = 0; /* --- envp --- */ VG_(client_envp) = (Char **)ptr; for (cpp = orig_envp; cpp && *cpp; ptr++, cpp++) *ptr = (Addr)copy_str(&strtab, *cpp); *ptr++ = 0; /* --- auxv --- */ auxv = (struct auxv *)ptr; *client_auxv = (UInt *)auxv; VG_(client_auxv) = (UWord *)*client_auxv; // ??? According to 'man proc', auxv is a array of unsigned long // terminated by two zeros. Why is valgrind working with UInt ? // We do not take ULong* (as ULong 8 bytes on a 32 bits), // => we take UWord* # if defined(VGP_ppc32_linux) || defined(VGP_ppc64_linux) auxv[0].a_type = AT_IGNOREPPC; auxv[0].u.a_val = AT_IGNOREPPC; auxv[1].a_type = AT_IGNOREPPC; auxv[1].u.a_val = AT_IGNOREPPC; auxv += 2; # endif for (; orig_auxv->a_type != AT_NULL; auxv++, orig_auxv++) { /* copy the entry... */ *auxv = *orig_auxv; /* ...and fix up / examine the copy */ switch(auxv->a_type) { case AT_IGNORE: case AT_PHENT: case AT_PAGESZ: case AT_FLAGS: case AT_NOTELF: case AT_UID: case AT_EUID: case AT_GID: case AT_EGID: case AT_CLKTCK: # if !defined(VGPV_arm_linux_android) && !defined(VGPV_x86_linux_android) case AT_FPUCW: /* missing on android */ # endif /* All these are pointerless, so we don't need to do anything about them. */ break; case AT_PHDR: if (info->phdr == 0) auxv->a_type = AT_IGNORE; else auxv->u.a_val = info->phdr; break; case AT_PHNUM: if (info->phdr == 0) auxv->a_type = AT_IGNORE; else auxv->u.a_val = info->phnum; break; case AT_BASE: /* When gdbserver sends the auxv to gdb, the AT_BASE has to be ignored, as otherwise gdb adds this offset to loaded shared libs, causing wrong address relocation e.g. when inserting breaks. However, ignoring AT_BASE makes V crash on Android 4.1. So, keep the AT_BASE on android for now. ??? Need to dig in depth about AT_BASE/GDB interaction */ # if !defined(VGPV_arm_linux_android) auxv->a_type = AT_IGNORE; # endif auxv->u.a_val = info->interp_base; break; case AT_PLATFORM: case AT_BASE_PLATFORM: /* points to a platform description string */ auxv->u.a_ptr = copy_str(&strtab, orig_auxv->u.a_ptr); break; case AT_ENTRY: auxv->u.a_val = info->entry; break; case AT_HWCAP: # if defined(VGP_arm_linux) { Bool has_neon = (auxv->u.a_val & VKI_HWCAP_NEON) > 0; VG_(debugLog)(2, "initimg", "ARM has-neon from-auxv: %s\n", has_neon ? "YES" : "NO"); VG_(machine_arm_set_has_NEON)( has_neon ); #define VKI_HWCAP_TLS 32768 Bool has_tls = (auxv->u.a_val & VKI_HWCAP_TLS) > 0; VG_(debugLog)(2, "initimg", "ARM has-tls from-auxv: %s\n", has_tls ? "YES" : "NO"); /* If real hw sets properly HWCAP_TLS, we might use this info to decide to really execute set_tls syscall in syswrap-arm-linux.c rather than to base this on conditional compilation. */ } # endif break; case AT_DCACHEBSIZE: case AT_ICACHEBSIZE: case AT_UCACHEBSIZE: # if defined(VGP_ppc32_linux) /* acquire cache info */ if (auxv->u.a_val > 0) { VG_(machine_ppc32_set_clszB)( auxv->u.a_val ); VG_(debugLog)(2, "initimg", "PPC32 cache line size %u (type %u)\n", (UInt)auxv->u.a_val, (UInt)auxv->a_type ); } # elif defined(VGP_ppc64_linux) /* acquire cache info */ if (auxv->u.a_val > 0) { VG_(machine_ppc64_set_clszB)( auxv->u.a_val ); VG_(debugLog)(2, "initimg", "PPC64 cache line size %u (type %u)\n", (UInt)auxv->u.a_val, (UInt)auxv->a_type ); } # endif break; # if defined(VGP_ppc32_linux) || defined(VGP_ppc64_linux) case AT_IGNOREPPC: break; # endif case AT_SECURE: /* If this is 1, then it means that this program is running suid, and therefore the dynamic linker should be careful about LD_PRELOAD, etc. However, since stage1 (the thing the kernel actually execve's) should never be SUID, and we need LD_PRELOAD to work for the client, we set AT_SECURE to 0. */ auxv->u.a_val = 0; break; case AT_SYSINFO: /* Trash this, because we don't reproduce it */ auxv->a_type = AT_IGNORE; break; # if !defined(VGP_ppc32_linux) && !defined(VGP_ppc64_linux) case AT_SYSINFO_EHDR: { /* Trash this, because we don't reproduce it */ const NSegment* ehdrseg = VG_(am_find_nsegment)((Addr)auxv->u.a_ptr); vg_assert(ehdrseg); VG_(am_munmap_valgrind)(ehdrseg->start, ehdrseg->end - ehdrseg->start); auxv->a_type = AT_IGNORE; break; } # endif case AT_RANDOM: /* points to 16 random bytes - we need to ensure this is propagated to the client as glibc will assume it is present if it is built for kernel 2.6.29 or later */ auxv->u.a_ptr = strtab; VG_(memcpy)(strtab, orig_auxv->u.a_ptr, 16); strtab += 16; break; case AT_EXECFN: /* points to the executable filename */ auxv->u.a_ptr = copy_str(&strtab, VG_(args_the_exename)); break; default: /* stomp out anything we don't know about */ VG_(debugLog)(2, "initimg", "stomping auxv entry %lld\n", (ULong)auxv->a_type); auxv->a_type = AT_IGNORE; break; } } *auxv = *orig_auxv; vg_assert(auxv->a_type == AT_NULL); vg_assert((strtab-stringbase) == stringsize); /* client_SP is pointing at client's argc/argv */ if (0) VG_(printf)("startup SP = %#lx\n", client_SP); return client_SP; } /* Allocate the client data segment. It is an expandable anonymous mapping abutting a shrinkable reservation of size max_dseg_size. The data segment starts at VG_(brk_base), which is page-aligned, and runs up to VG_(brk_limit), which isn't. */ static void setup_client_dataseg ( SizeT max_size ) { Bool ok; SysRes sres; Addr anon_start = VG_(brk_base); SizeT anon_size = VKI_PAGE_SIZE; Addr resvn_start = anon_start + anon_size; SizeT resvn_size = max_size - anon_size; vg_assert(VG_IS_PAGE_ALIGNED(anon_size)); vg_assert(VG_IS_PAGE_ALIGNED(resvn_size)); vg_assert(VG_IS_PAGE_ALIGNED(anon_start)); vg_assert(VG_IS_PAGE_ALIGNED(resvn_start)); /* Because there's been no brk activity yet: */ vg_assert(VG_(brk_base) == VG_(brk_limit)); /* Try to create the data seg and associated reservation where VG_(brk_base) says. */ ok = VG_(am_create_reservation)( resvn_start, resvn_size, SmLower, anon_size ); if (!ok) { /* Hmm, that didn't work. Well, let aspacem suggest an address it likes better, and try again with that. */ anon_start = VG_(am_get_advisory_client_simple) ( 0/*floating*/, anon_size+resvn_size, &ok ); if (ok) { resvn_start = anon_start + anon_size; ok = VG_(am_create_reservation)( resvn_start, resvn_size, SmLower, anon_size ); if (ok) VG_(brk_base) = VG_(brk_limit) = anon_start; } /* that too might have failed, but if it has, we're hosed: there is no Plan C. */ } vg_assert(ok); /* We make the data segment (heap) executable because LinuxThreads on ppc32 creates trampolines in this area. Also, on x86/Linux the data segment is RWX natively, at least according to /proc/self/maps. Also, having a non-executable data seg would kill any program which tried to create code in the data seg and then run it. */ sres = VG_(am_mmap_anon_fixed_client)( anon_start, anon_size, VKI_PROT_READ|VKI_PROT_WRITE|VKI_PROT_EXEC ); vg_assert(!sr_isError(sres)); vg_assert(sr_Res(sres) == anon_start); } /*====================================================================*/ /*=== TOP-LEVEL: VG_(setup_client_initial_image) ===*/ /*====================================================================*/ /* Create the client's initial memory image. */ IIFinaliseImageInfo VG_(ii_create_image)( IICreateImageInfo iicii ) { ExeInfo info; HChar** env = NULL; IIFinaliseImageInfo iifii; VG_(memset)( &iifii, 0, sizeof(iifii) ); //-------------------------------------------------------------- // Load client executable, finding in $PATH if necessary // p: get_helprequest_and_toolname() [for 'exec', 'need_help'] // p: layout_remaining_space [so there's space] //-------------------------------------------------------------- VG_(debugLog)(1, "initimg", "Loading client\n"); if (VG_(args_the_exename) == NULL) VG_(err_missing_prog)(); load_client(&info, &iifii.initial_client_IP, &iifii.initial_client_TOC); //-------------------------------------------------------------- // Set up client's environment // p: set-libdir [for VG_(libdir)] // p: get_helprequest_and_toolname [for toolname] //-------------------------------------------------------------- VG_(debugLog)(1, "initimg", "Setup client env\n"); env = setup_client_env(iicii.envp, iicii.toolname); //-------------------------------------------------------------- // Setup client stack, eip, and VG_(client_arg[cv]) // p: load_client() [for 'info'] // p: fix_environment() [for 'env'] //-------------------------------------------------------------- { /* When allocating space for the client stack on Linux, take notice of the --main-stacksize value. This makes it possible to run programs with very large (primary) stack requirements simply by specifying --main-stacksize. */ /* Logic is as follows: - by default, use the client's current stack rlimit - if that exceeds 16M, clamp to 16M - if a larger --main-stacksize value is specified, use that instead - in all situations, the minimum allowed stack size is 1M */ void* init_sp = iicii.argv - 1; SizeT m1 = 1024 * 1024; SizeT m16 = 16 * m1; SizeT szB = (SizeT)VG_(client_rlimit_stack).rlim_cur; if (szB < m1) szB = m1; if (szB > m16) szB = m16; if (VG_(clo_main_stacksize) > 0) szB = VG_(clo_main_stacksize); if (szB < m1) szB = m1; szB = VG_PGROUNDUP(szB); VG_(debugLog)(1, "initimg", "Setup client stack: size will be %ld\n", szB); iifii.clstack_max_size = szB; iifii.initial_client_SP = setup_client_stack( init_sp, env, &info, &iifii.client_auxv, iicii.clstack_top, iifii.clstack_max_size ); VG_(free)(env); VG_(debugLog)(2, "initimg", "Client info: " "initial_IP=%p initial_TOC=%p brk_base=%p\n", (void*)(iifii.initial_client_IP), (void*)(iifii.initial_client_TOC), (void*)VG_(brk_base) ); VG_(debugLog)(2, "initimg", "Client info: " "initial_SP=%p max_stack_size=%ld\n", (void*)(iifii.initial_client_SP), (SizeT)iifii.clstack_max_size ); } //-------------------------------------------------------------- // Setup client data (brk) segment. Initially a 1-page segment // which abuts a shrinkable reservation. // p: load_client() [for 'info' and hence VG_(brk_base)] //-------------------------------------------------------------- { SizeT m1 = 1024 * 1024; SizeT m8 = 8 * m1; SizeT dseg_max_size = (SizeT)VG_(client_rlimit_data).rlim_cur; VG_(debugLog)(1, "initimg", "Setup client data (brk) segment\n"); if (dseg_max_size < m1) dseg_max_size = m1; if (dseg_max_size > m8) dseg_max_size = m8; dseg_max_size = VG_PGROUNDUP(dseg_max_size); setup_client_dataseg( dseg_max_size ); } return iifii; } /*====================================================================*/ /*=== TOP-LEVEL: VG_(finalise_thread1state) ===*/ /*====================================================================*/ /* Just before starting the client, we may need to make final adjustments to its initial image. Also we need to set up the VEX guest state for thread 1 (the root thread) and copy in essential starting values. This is handed the IIFinaliseImageInfo created by VG_(ii_create_image). */ void VG_(ii_finalise_image)( IIFinaliseImageInfo iifii ) { ThreadArchState* arch = &VG_(threads)[1].arch; /* On Linux we get client_{ip/sp/toc}, and start the client with all other registers zeroed. */ # if defined(VGP_x86_linux) vg_assert(0 == sizeof(VexGuestX86State) % 16); /* Zero out the initial state, and set up the simulated FPU in a sane way. */ LibVEX_GuestX86_initialise(&arch->vex); /* Zero out the shadow areas. */ VG_(memset)(&arch->vex_shadow1, 0, sizeof(VexGuestX86State)); VG_(memset)(&arch->vex_shadow2, 0, sizeof(VexGuestX86State)); /* Put essential stuff into the new state. */ arch->vex.guest_ESP = iifii.initial_client_SP; arch->vex.guest_EIP = iifii.initial_client_IP; /* initialise %cs, %ds and %ss to point at the operating systems default code, data and stack segments. Also %es (see #291253). */ asm volatile("movw %%cs, %0" : : "m" (arch->vex.guest_CS)); asm volatile("movw %%ds, %0" : : "m" (arch->vex.guest_DS)); asm volatile("movw %%ss, %0" : : "m" (arch->vex.guest_SS)); asm volatile("movw %%es, %0" : : "m" (arch->vex.guest_ES)); # elif defined(VGP_amd64_linux) vg_assert(0 == sizeof(VexGuestAMD64State) % 16); /* Zero out the initial state, and set up the simulated FPU in a sane way. */ LibVEX_GuestAMD64_initialise(&arch->vex); /* Zero out the shadow areas. */ VG_(memset)(&arch->vex_shadow1, 0, sizeof(VexGuestAMD64State)); VG_(memset)(&arch->vex_shadow2, 0, sizeof(VexGuestAMD64State)); /* Put essential stuff into the new state. */ arch->vex.guest_RSP = iifii.initial_client_SP; arch->vex.guest_RIP = iifii.initial_client_IP; # elif defined(VGP_ppc32_linux) vg_assert(0 == sizeof(VexGuestPPC32State) % 16); /* Zero out the initial state, and set up the simulated FPU in a sane way. */ LibVEX_GuestPPC32_initialise(&arch->vex); /* Zero out the shadow areas. */ VG_(memset)(&arch->vex_shadow1, 0, sizeof(VexGuestPPC32State)); VG_(memset)(&arch->vex_shadow2, 0, sizeof(VexGuestPPC32State)); /* Put essential stuff into the new state. */ arch->vex.guest_GPR1 = iifii.initial_client_SP; arch->vex.guest_CIA = iifii.initial_client_IP; # elif defined(VGP_ppc64_linux) vg_assert(0 == sizeof(VexGuestPPC64State) % 16); /* Zero out the initial state, and set up the simulated FPU in a sane way. */ LibVEX_GuestPPC64_initialise(&arch->vex); /* Zero out the shadow areas. */ VG_(memset)(&arch->vex_shadow1, 0, sizeof(VexGuestPPC64State)); VG_(memset)(&arch->vex_shadow2, 0, sizeof(VexGuestPPC64State)); /* Put essential stuff into the new state. */ arch->vex.guest_GPR1 = iifii.initial_client_SP; arch->vex.guest_GPR2 = iifii.initial_client_TOC; arch->vex.guest_CIA = iifii.initial_client_IP; # elif defined(VGP_arm_linux) /* Zero out the initial state, and set up the simulated FPU in a sane way. */ LibVEX_GuestARM_initialise(&arch->vex); /* Zero out the shadow areas. */ VG_(memset)(&arch->vex_shadow1, 0, sizeof(VexGuestARMState)); VG_(memset)(&arch->vex_shadow2, 0, sizeof(VexGuestARMState)); arch->vex.guest_R13 = iifii.initial_client_SP; arch->vex.guest_R15T = iifii.initial_client_IP; /* This is just EABI stuff. */ // FIXME jrs: what's this for? arch->vex.guest_R1 = iifii.initial_client_SP; # elif defined(VGP_s390x_linux) vg_assert(0 == sizeof(VexGuestS390XState) % 16); /* Zero out the initial state. This also sets the guest_fpc to 0, which is also done by the kernel for the fpc during execve. */ LibVEX_GuestS390X_initialise(&arch->vex); /* Mark all registers as undefined ... */ VG_(memset)(&arch->vex_shadow1, 0xFF, sizeof(VexGuestS390XState)); VG_(memset)(&arch->vex_shadow2, 0x00, sizeof(VexGuestS390XState)); /* ... except SP, FPC, and IA */ VG_(memset)((UChar *)&arch->vex_shadow1 + VG_O_STACK_PTR, 0x00, 8); VG_(memset)((UChar *)&arch->vex_shadow1 + VG_O_FPC_REG, 0x00, 4); VG_(memset)((UChar *)&arch->vex_shadow1 + VG_O_INSTR_PTR, 0x00, 8); /* Put essential stuff into the new state. */ arch->vex.guest_SP = iifii.initial_client_SP; arch->vex.guest_IA = iifii.initial_client_IP; /* See sys_execve in <linux>/arch/s390/kernel/process.c */ arch->vex.guest_fpc = 0; /* Tell the tool about the registers we just wrote */ VG_TRACK(post_reg_write, Vg_CoreStartup, /*tid*/1, VG_O_STACK_PTR, 8); VG_TRACK(post_reg_write, Vg_CoreStartup, /*tid*/1, VG_O_FPC_REG, 4); VG_TRACK(post_reg_write, Vg_CoreStartup, /*tid*/1, VG_O_INSTR_PTR, 8); return; # elif defined(VGP_mips32_linux) vg_assert(0 == sizeof(VexGuestMIPS32State) % 16); /* Zero out the initial state, and set up the simulated FPU in a sane way. */ LibVEX_GuestMIPS32_initialise(&arch->vex); /* Zero out the shadow areas. */ VG_(memset)(&arch->vex_shadow1, 0, sizeof(VexGuestMIPS32State)); VG_(memset)(&arch->vex_shadow2, 0, sizeof(VexGuestMIPS32State)); arch->vex.guest_r29 = iifii.initial_client_SP; arch->vex.guest_PC = iifii.initial_client_IP; arch->vex.guest_r31 = iifii.initial_client_SP; # else # error Unknown platform # endif /* Tell the tool that we just wrote to the registers. */ VG_TRACK( post_reg_write, Vg_CoreStartup, /*tid*/1, /*offset*/0, sizeof(VexGuestArchState)); } #endif // defined(VGO_linux) /*--------------------------------------------------------------------*/ /*--- ---*/ /*--------------------------------------------------------------------*/