diff options
Diffstat (limited to 'src/ldso')
| -rw-r--r-- | src/ldso/arm/start.s | 7 | ||||
| -rw-r--r-- | src/ldso/dynlink.c | 89 | ||||
| -rw-r--r-- | src/ldso/i386/start.s | 6 | ||||
| -rw-r--r-- | src/ldso/x86_64/start.s | 8 |
4 files changed, 89 insertions, 21 deletions
diff --git a/src/ldso/arm/start.s b/src/ldso/arm/start.s index 25675782..dfa36578 100644 --- a/src/ldso/arm/start.s +++ b/src/ldso/arm/start.s @@ -4,6 +4,13 @@ _start: ldr r0,[sp] add r1,sp,#4 bl __dynlink + pop {r1} +1: sub r1,r1,#1 + pop {r2} + cmp r2,#-1 + beq 1b + add r1,r1,#1 + push {r1,r2} mov r1,r0 mov r0,#0 tst r1,#1 diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c index 02c880b4..820e8a36 100644 --- a/src/ldso/dynlink.c +++ b/src/ldso/dynlink.c @@ -64,6 +64,7 @@ struct dso { char relocated; char constructed; struct dso **deps; + char *shortname; char buf[]; }; @@ -74,6 +75,7 @@ static char *env_path, *sys_path, *r_path; static int rtld_used; static int ssp_used; static int runtime; +static int ldd_mode; static jmp_buf rtld_fail; static pthread_rwlock_t lock; static struct debug debug; @@ -293,9 +295,8 @@ static void *map_library(int fd, size_t *lenp, unsigned char **basep, size_t *dy return map; } -static int path_open(const char *name, const char *search) +static int path_open(const char *name, const char *search, char *buf, size_t buf_size) { - char buf[2*NAME_MAX+2]; const char *s=search, *z; int l, fd; for (;;) { @@ -303,7 +304,7 @@ static int path_open(const char *name, const char *search) if (!*s) return -1; z = strchr(s, ':'); l = z ? z-s : strlen(s); - snprintf(buf, sizeof buf, "%.*s/%s", l, s, name); + snprintf(buf, buf_size, "%.*s/%s", l, s, name); if ((fd = open(buf, O_RDONLY))>=0) return fd; s += l; } @@ -320,6 +321,7 @@ static void decode_dyn(struct dso *p) static struct dso *load_library(const char *name) { + char buf[2*NAME_MAX+2]; unsigned char *base, *map; size_t dyno, map_len; struct dso *p; @@ -346,7 +348,7 @@ static struct dso *load_library(const char *name) } /* Search for the name to see if it's already loaded */ for (p=head->next; p; p=p->next) { - if (!strcmp(p->name, name)) { + if (!strcmp(p->shortname, name)) { p->refcnt++; return p; } @@ -356,8 +358,8 @@ static struct dso *load_library(const char *name) } else { if (strlen(name) > NAME_MAX) return 0; fd = -1; - if (r_path) fd = path_open(name, r_path); - if (fd < 0 && env_path) fd = path_open(name, env_path); + if (r_path) fd = path_open(name, r_path, buf, sizeof buf); + if (fd < 0 && env_path) fd = path_open(name, env_path, buf, sizeof buf); if (fd < 0) { if (!sys_path) { FILE *f = fopen(ETC_LDSO_PATH, "r"); @@ -367,8 +369,8 @@ static struct dso *load_library(const char *name) fclose(f); } } - if (sys_path) fd = path_open(name, sys_path); - else fd = path_open(name, "/lib:/usr/local/lib:/usr/lib"); + if (sys_path) fd = path_open(name, sys_path, buf, sizeof buf); + else fd = path_open(name, "/lib:/usr/local/lib:/usr/lib", buf, sizeof buf); } } if (fd < 0) return 0; @@ -386,7 +388,7 @@ static struct dso *load_library(const char *name) map = map_library(fd, &map_len, &base, &dyno); close(fd); if (!map) return 0; - p = calloc(1, sizeof *p + strlen(name) + 1); + p = calloc(1, sizeof *p + strlen(buf) + 1); if (!p) { munmap(map, map_len); return 0; @@ -402,12 +404,16 @@ static struct dso *load_library(const char *name) p->ino = st.st_ino; p->refcnt = 1; p->name = p->buf; - strcpy(p->name, name); + strcpy(p->name, buf); + if (!strchr(name, '/')) p->shortname = strrchr(p->name, '/'); + if (!p->shortname) p->shortname = p->name; tail->next = p; p->prev = tail; tail = p; + if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, buf, base); + return p; } @@ -543,10 +549,19 @@ void *__dynlink(int argc, char **argv) env_preload = 0; } + /* If the dynamic linker was invoked as a program itself, AT_BASE + * will not be set. In that case, we assume the base address is + * the start of the page containing the PHDRs; I don't know any + * better approach... */ + if (!aux[AT_BASE]) { + aux[AT_BASE] = aux[AT_PHDR] & -PAGE_SIZE; + aux[AT_PHDR] = aux[AT_PHENT] = aux[AT_PHNUM] = 0; + } + /* The dynamic linker load address is passed by the kernel * in the AUX vector, so this is easy. */ lib->base = (void *)aux[AT_BASE]; - lib->name = "libc.so"; + lib->name = lib->shortname = "libc.so"; lib->global = 1; ehdr = (void *)lib->base; lib->dynv = (void *)(lib->base + find_dyn( @@ -554,18 +569,48 @@ void *__dynlink(int argc, char **argv) ehdr->e_phnum, ehdr->e_phentsize)); decode_dyn(lib); - /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */ - app->base = 0; - phdr = (void *)aux[AT_PHDR]; - for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) { - if (phdr->p_type == PT_PHDR) - app->base = (void *)(aux[AT_PHDR] - phdr->p_vaddr); + if (aux[AT_PHDR]) { + /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */ + phdr = (void *)aux[AT_PHDR]; + for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) { + if (phdr->p_type == PT_PHDR) + app->base = (void *)(aux[AT_PHDR] - phdr->p_vaddr); + } + app->name = app->shortname = argv[0]; + app->dynv = (void *)(app->base + find_dyn( + (void *)aux[AT_PHDR], aux[AT_PHNUM], aux[AT_PHENT])); + } else { + int fd; + char *ldname = argv[0]; + size_t dyno, l = strlen(ldname); + if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1; + *argv++ = (void *)-1; + if (argv[0] && !strcmp(argv[0], "--")) *argv++ = (void *)-1; + if (!argv[0]) { + dprintf(2, "musl libc/dynamic program loader\n"); + dprintf(2, "usage: %s pathname%s\n", ldname, + ldd_mode ? "" : " [args]"); + _exit(1); + } + fd = open(argv[0], O_RDONLY); + if (fd < 0) { + dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno)); + _exit(1); + } + runtime = 1; + ehdr = (void *)map_library(fd, &app->map_len, &app->base, &dyno); + if (!ehdr) { + dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]); + _exit(1); + } + runtime = 0; + close(fd); + app->name = app->shortname = argv[0]; + app->dynv = (void *)(app->base + dyno); + aux[AT_ENTRY] = ehdr->e_entry; } - app->name = argv[0]; app->global = 1; app->constructed = 1; - app->dynv = (void *)(app->base + find_dyn( - (void *)aux[AT_PHDR], aux[AT_PHNUM], aux[AT_PHENT])); decode_dyn(app); /* Attach to vdso, if provided by the kernel */ @@ -580,7 +625,7 @@ void *__dynlink(int argc, char **argv) if (phdr->p_type == PT_LOAD) vdso->base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset); } - vdso->name = "linux-gate.so.1"; + vdso->name = vdso->shortname = "linux-gate.so.1"; vdso->global = 1; decode_dyn(vdso); vdso->prev = lib; @@ -616,6 +661,8 @@ void *__dynlink(int argc, char **argv) reloc_all(app->next); reloc_all(app); + if (ldd_mode) _exit(0); + /* Switch to runtime mode: any further failures in the dynamic * linker are a reportable failure rather than a fatal startup * error. If the dynamic loader (dlopen) will not be used, free diff --git a/src/ldso/i386/start.s b/src/ldso/i386/start.s index f6d49291..b16f8af5 100644 --- a/src/ldso/i386/start.s +++ b/src/ldso/i386/start.s @@ -11,6 +11,12 @@ _start: push %edi call __dynlink mov %esi,%esp +1: dec %edi + pop %esi + cmp $-1,%esi + jz 1b + inc %edi + push %esi push %edi xor %edx,%edx jmp *%eax diff --git a/src/ldso/x86_64/start.s b/src/ldso/x86_64/start.s index 65e238b7..80c1d08d 100644 --- a/src/ldso/x86_64/start.s +++ b/src/ldso/x86_64/start.s @@ -4,5 +4,13 @@ _start: mov (%rsp),%rdi lea 8(%rsp),%rsi call __dynlink + pop %rdi +1: dec %edi + pop %rsi + cmp $-1,%rsi + jz 1b + inc %edi + push %rsi + push %rdi xor %edx,%edx jmp *%rax |