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-rw-r--r--src/ldso/arm/start.s7
-rw-r--r--src/ldso/dynlink.c89
-rw-r--r--src/ldso/i386/start.s6
-rw-r--r--src/ldso/x86_64/start.s8
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
generated by cgit v1.2.1 (git 2.18.0) at 2025-10-31 03:55:25 +0000