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-rw-r--r--linux-user/elfload.c110
-rw-r--r--linux-user/flatload.c2
-rw-r--r--linux-user/linuxload.c7
-rw-r--r--linux-user/qemu.h7
-rw-r--r--linux-user/syscall.c6
5 files changed, 56 insertions, 76 deletions
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index ad46530f83..fdae6a6cd1 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -1373,66 +1373,69 @@ static bool elf_check_ehdr(struct elfhdr *ehdr)
* to be put directly into the top of new user memory.
*
*/
-static abi_ulong copy_elf_strings(int argc,char ** argv, void **page,
- abi_ulong p)
+static abi_ulong copy_elf_strings(int argc, char **argv, char *scratch,
+ abi_ulong p, abi_ulong stack_limit)
{
- char *tmp, *tmp1, *pag = NULL;
- int len, offset = 0;
+ char *tmp;
+ int len, offset;
+ abi_ulong top = p;
if (!p) {
return 0; /* bullet-proofing */
}
+
+ offset = ((p - 1) % TARGET_PAGE_SIZE) + 1;
+
while (argc-- > 0) {
tmp = argv[argc];
if (!tmp) {
fprintf(stderr, "VFS: argc is wrong");
exit(-1);
}
- tmp1 = tmp;
- while (*tmp++);
- len = tmp - tmp1;
- if (p < len) { /* this shouldn't happen - 128kB */
+ len = strlen(tmp) + 1;
+ tmp += len;
+
+ if (len > (p - stack_limit)) {
return 0;
}
while (len) {
- --p; --tmp; --len;
- if (--offset < 0) {
- offset = p % TARGET_PAGE_SIZE;
- pag = (char *)page[p/TARGET_PAGE_SIZE];
- if (!pag) {
- pag = g_try_malloc0(TARGET_PAGE_SIZE);
- page[p/TARGET_PAGE_SIZE] = pag;
- if (!pag)
- return 0;
- }
- }
- if (len == 0 || offset == 0) {
- *(pag + offset) = *tmp;
- }
- else {
- int bytes_to_copy = (len > offset) ? offset : len;
- tmp -= bytes_to_copy;
- p -= bytes_to_copy;
- offset -= bytes_to_copy;
- len -= bytes_to_copy;
- memcpy_fromfs(pag + offset, tmp, bytes_to_copy + 1);
+ int bytes_to_copy = (len > offset) ? offset : len;
+ tmp -= bytes_to_copy;
+ p -= bytes_to_copy;
+ offset -= bytes_to_copy;
+ len -= bytes_to_copy;
+
+ memcpy_fromfs(scratch + offset, tmp, bytes_to_copy);
+
+ if (offset == 0) {
+ memcpy_to_target(p, scratch, top - p);
+ top = p;
+ offset = TARGET_PAGE_SIZE;
}
}
}
+ if (offset) {
+ memcpy_to_target(p, scratch + offset, top - p);
+ }
+
return p;
}
-static abi_ulong setup_arg_pages(abi_ulong p, struct linux_binprm *bprm,
+/* Older linux kernels provide up to MAX_ARG_PAGES (default: 32) of
+ * argument/environment space. Newer kernels (>2.6.33) allow more,
+ * dependent on stack size, but guarantee at least 32 pages for
+ * backwards compatibility.
+ */
+#define STACK_LOWER_LIMIT (32 * TARGET_PAGE_SIZE)
+
+static abi_ulong setup_arg_pages(struct linux_binprm *bprm,
struct image_info *info)
{
- abi_ulong stack_base, size, error, guard;
- int i;
+ abi_ulong size, error, guard;
- /* Create enough stack to hold everything. If we don't use
- it for args, we'll use it for something else. */
size = guest_stack_size;
- if (size < MAX_ARG_PAGES*TARGET_PAGE_SIZE) {
- size = MAX_ARG_PAGES*TARGET_PAGE_SIZE;
+ if (size < STACK_LOWER_LIMIT) {
+ size = STACK_LOWER_LIMIT;
}
guard = TARGET_PAGE_SIZE;
if (guard < qemu_real_host_page_size) {
@@ -1450,18 +1453,8 @@ static abi_ulong setup_arg_pages(abi_ulong p, struct linux_binprm *bprm,
target_mprotect(error, guard, PROT_NONE);
info->stack_limit = error + guard;
- stack_base = info->stack_limit + size - MAX_ARG_PAGES*TARGET_PAGE_SIZE;
- p += stack_base;
-
- for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
- if (bprm->page[i]) {
- /* FIXME - check return value of memcpy_to_target() for failure */
- memcpy_to_target(stack_base, bprm->page[i], TARGET_PAGE_SIZE);
- g_free(bprm->page[i]);
- }
- stack_base += TARGET_PAGE_SIZE;
- }
- return p;
+
+ return info->stack_limit + size - sizeof(void *);
}
/* Map and zero the bss. We need to explicitly zero any fractional pages
@@ -2203,6 +2196,7 @@ int load_elf_binary(struct linux_binprm *bprm, struct image_info *info)
struct image_info interp_info;
struct elfhdr elf_ex;
char *elf_interpreter = NULL;
+ char *scratch;
info->start_mmap = (abi_ulong)ELF_START_MMAP;
@@ -2214,18 +2208,24 @@ int load_elf_binary(struct linux_binprm *bprm, struct image_info *info)
when we load the interpreter. */
elf_ex = *(struct elfhdr *)bprm->buf;
- bprm->p = copy_elf_strings(1, &bprm->filename, bprm->page, bprm->p);
- bprm->p = copy_elf_strings(bprm->envc,bprm->envp,bprm->page,bprm->p);
- bprm->p = copy_elf_strings(bprm->argc,bprm->argv,bprm->page,bprm->p);
+ /* Do this so that we can load the interpreter, if need be. We will
+ change some of these later */
+ bprm->p = setup_arg_pages(bprm, info);
+
+ scratch = g_new0(char, TARGET_PAGE_SIZE);
+ bprm->p = copy_elf_strings(1, &bprm->filename, scratch,
+ bprm->p, info->stack_limit);
+ bprm->p = copy_elf_strings(bprm->envc, bprm->envp, scratch,
+ bprm->p, info->stack_limit);
+ bprm->p = copy_elf_strings(bprm->argc, bprm->argv, scratch,
+ bprm->p, info->stack_limit);
+ g_free(scratch);
+
if (!bprm->p) {
fprintf(stderr, "%s: %s\n", bprm->filename, strerror(E2BIG));
exit(-1);
}
- /* Do this so that we can load the interpreter, if need be. We will
- change some of these later */
- bprm->p = setup_arg_pages(bprm->p, bprm, info);
-
if (elf_interpreter) {
load_elf_interp(elf_interpreter, &interp_info, bprm->buf);
diff --git a/linux-user/flatload.c b/linux-user/flatload.c
index 566a7a87a3..ceacb9844a 100644
--- a/linux-user/flatload.c
+++ b/linux-user/flatload.c
@@ -707,7 +707,7 @@ static int load_flat_shared_library(int id, struct lib_info *libs)
int load_flt_binary(struct linux_binprm *bprm, struct image_info *info)
{
struct lib_info libinfo[MAX_SHARED_LIBS];
- abi_ulong p = bprm->p;
+ abi_ulong p;
abi_ulong stack_len;
abi_ulong start_addr;
abi_ulong sp;
diff --git a/linux-user/linuxload.c b/linux-user/linuxload.c
index 506e837ae1..dbaf0ec586 100644
--- a/linux-user/linuxload.c
+++ b/linux-user/linuxload.c
@@ -135,10 +135,7 @@ int loader_exec(int fdexec, const char *filename, char **argv, char **envp,
struct linux_binprm *bprm)
{
int retval;
- int i;
- bprm->p = TARGET_PAGE_SIZE*MAX_ARG_PAGES-sizeof(unsigned int);
- memset(bprm->page, 0, sizeof(bprm->page));
bprm->fd = fdexec;
bprm->filename = (char *)filename;
bprm->argc = count(argv);
@@ -172,9 +169,5 @@ int loader_exec(int fdexec, const char *filename, char **argv, char **envp,
return retval;
}
- /* Something went wrong, return the inode and free the argument pages*/
- for (i=0 ; i<MAX_ARG_PAGES ; i++) {
- g_free(bprm->page[i]);
- }
return(retval);
}
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index 678e5d602e..bd90cc3799 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -143,12 +143,6 @@ extern const char *qemu_uname_release;
extern unsigned long mmap_min_addr;
/* ??? See if we can avoid exposing so much of the loader internals. */
-/*
- * MAX_ARG_PAGES defines the number of pages allocated for arguments
- * and envelope for the new program. 32 should suffice, this gives
- * a maximum env+arg of 128kB w/4KB pages!
- */
-#define MAX_ARG_PAGES 33
/* Read a good amount of data initially, to hopefully get all the
program headers loaded. */
@@ -160,7 +154,6 @@ extern unsigned long mmap_min_addr;
*/
struct linux_binprm {
char buf[BPRM_BUF_SIZE] __attribute__((aligned));
- void *page[MAX_ARG_PAGES];
abi_ulong p;
int fd;
int e_uid, e_gid;
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index d1d3eb2d78..7fbaa8bb67 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -5808,12 +5808,6 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
}
*q = NULL;
- /* This case will not be caught by the host's execve() if its
- page size is bigger than the target's. */
- if (total_size > MAX_ARG_PAGES * TARGET_PAGE_SIZE) {
- ret = -TARGET_E2BIG;
- goto execve_end;
- }
if (!(p = lock_user_string(arg1)))
goto execve_efault;
ret = get_errno(execve(p, argp, envp));
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-15 12:09:09 +0000