mm: variable length argument support
Changes
15 files changed · +554 −453
| File | Status | Add | Del | Content |
|---|---|---|---|---|
| arch/ia64/ia32/binfmt_elf32.c | modified | +16 | −51 | View file |
| arch/x86_64/ia32/ia32_aout.c | modified | +1 | −1 | View file |
| arch/x86_64/ia32/ia32_binfmt.c | modified | +0 | −58 | View file |
| fs/binfmt_elf.c | modified | +19 | −9 | View file |
| fs/binfmt_elf_fdpic.c | modified | +4 | −4 | View file |
| fs/binfmt_misc.c | modified | +3 | −1 | View file |
| fs/binfmt_script.c | modified | +3 | −1 | View file |
| fs/compat.c | modified | +53 | −75 | View file |
| fs/exec.c | modified | +396 | −218 | View file |
| include/linux/binfmts.h | modified | +13 | −5 | View file |
| include/linux/mm.h | modified | +8 | −1 | View file |
| kernel/auditsc.c | modified | +1 | −1 | View file |
| mm/mmap.c | modified | +35 | −26 | View file |
| mm/mprotect.c | modified | +1 | −1 | View file |
| mm/mremap.c | modified | +1 | −1 | View file |
Only the first 600 diff lines are shown. Download the complete patch.
arch/ia64/ia32/binfmt_elf32.c
View filediff --git a/arch/ia64/ia32/binfmt_elf32.c b/arch/ia64/ia32/binfmt_elf32.c
index 6f4d3d0..e1189ba 100644
--- a/arch/ia64/ia32/binfmt_elf32.c
+++ b/arch/ia64/ia32/binfmt_elf32.c
@@ -195,62 +195,27 @@ ia64_elf32_init (struct pt_regs *regs)
ia32_load_state(current);
}
+/*
+ * Undo the override of setup_arg_pages() without this ia32_setup_arg_pages()
+ * will suffer infinite self recursion.
+ */
+#undef setup_arg_pages
+
int
ia32_setup_arg_pages (struct linux_binprm *bprm, int executable_stack)
{
- unsigned long stack_base;
- struct vm_area_struct *mpnt;
- struct mm_struct *mm = current->mm;
- int i, ret;
-
- stack_base = IA32_STACK_TOP - MAX_ARG_PAGES*PAGE_SIZE;
- mm->arg_start = bprm->p + stack_base;
-
- bprm->p += stack_base;
- if (bprm->loader)
- bprm->loader += stack_base;
- bprm->exec += stack_base;
-
- mpnt = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
- if (!mpnt)
- return -ENOMEM;
-
- down_write(¤t->mm->mmap_sem);
- {
- mpnt->vm_mm = current->mm;
- mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p;
- mpnt->vm_end = IA32_STACK_TOP;
- if (executable_stack == EXSTACK_ENABLE_X)
- mpnt->vm_flags = VM_STACK_FLAGS | VM_EXEC;
- else if (executable_stack == EXSTACK_DISABLE_X)
- mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC;
- else
- mpnt->vm_flags = VM_STACK_FLAGS;
- mpnt->vm_page_prot = (mpnt->vm_flags & VM_EXEC)?
- PAGE_COPY_EXEC: PAGE_COPY;
- if ((ret = insert_vm_struct(current->mm, mpnt))) {
- up_write(¤t->mm->mmap_sem);
- kmem_cache_free(vm_area_cachep, mpnt);
- return ret;
- }
- current->mm->stack_vm = current->mm->total_vm = vma_pages(mpnt);
+ int ret;
+
+ ret = setup_arg_pages(bprm, IA32_STACK_TOP, executable_stack);
+ if (!ret) {
+ /*
+ * Can't do it in ia64_elf32_init(). Needs to be done before
+ * calls to elf32_map()
+ */
+ current->thread.ppl = ia32_init_pp_list();
}
- for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
- struct page *page = bprm->page[i];
- if (page) {
- bprm->page[i] = NULL;
- install_arg_page(mpnt, page, stack_base);
- }
- stack_base += PAGE_SIZE;
- }
- up_write(¤t->mm->mmap_sem);
-
- /* Can't do it in ia64_elf32_init(). Needs to be done before calls to
- elf32_map() */
- current->thread.ppl = ia32_init_pp_list();
-
- return 0;
+ return ret;
}
static void
arch/x86_64/ia32/ia32_aout.c
View filediff --git a/arch/x86_64/ia32/ia32_aout.c b/arch/x86_64/ia32/ia32_aout.c
index fe83edb..0878137 100644
--- a/arch/x86_64/ia32/ia32_aout.c
+++ b/arch/x86_64/ia32/ia32_aout.c
@@ -404,7 +404,7 @@ beyond_if:
set_brk(current->mm->start_brk, current->mm->brk);
- retval = ia32_setup_arg_pages(bprm, IA32_STACK_TOP, EXSTACK_DEFAULT);
+ retval = setup_arg_pages(bprm, IA32_STACK_TOP, EXSTACK_DEFAULT);
if (retval < 0) {
/* Someone check-me: is this error path enough? */
send_sig(SIGKILL, current, 0);
arch/x86_64/ia32/ia32_binfmt.c
View filediff --git a/arch/x86_64/ia32/ia32_binfmt.c b/arch/x86_64/ia32/ia32_binfmt.c
index 185399b..ed56a88 100644
--- a/arch/x86_64/ia32/ia32_binfmt.c
+++ b/arch/x86_64/ia32/ia32_binfmt.c
@@ -232,9 +232,6 @@ do { \
#define load_elf_binary load_elf32_binary
#define ELF_PLAT_INIT(r, load_addr) elf32_init(r)
-#define setup_arg_pages(bprm, stack_top, exec_stack) \
- ia32_setup_arg_pages(bprm, stack_top, exec_stack)
-int ia32_setup_arg_pages(struct linux_binprm *bprm, unsigned long stack_top, int executable_stack);
#undef start_thread
#define start_thread(regs,new_rip,new_rsp) do { \
@@ -286,61 +283,6 @@ static void elf32_init(struct pt_regs *regs)
me->thread.es = __USER_DS;
}
-int ia32_setup_arg_pages(struct linux_binprm *bprm, unsigned long stack_top,
- int executable_stack)
-{
- unsigned long stack_base;
- struct vm_area_struct *mpnt;
- struct mm_struct *mm = current->mm;
- int i, ret;
-
- stack_base = stack_top - MAX_ARG_PAGES * PAGE_SIZE;
- mm->arg_start = bprm->p + stack_base;
-
- bprm->p += stack_base;
- if (bprm->loader)
- bprm->loader += stack_base;
- bprm->exec += stack_base;
-
- mpnt = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
- if (!mpnt)
- return -ENOMEM;
-
- down_write(&mm->mmap_sem);
- {
- mpnt->vm_mm = mm;
- mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p;
- mpnt->vm_end = stack_top;
- if (executable_stack == EXSTACK_ENABLE_X)
- mpnt->vm_flags = VM_STACK_FLAGS | VM_EXEC;
- else if (executable_stack == EXSTACK_DISABLE_X)
- mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC;
- else
- mpnt->vm_flags = VM_STACK_FLAGS;
- mpnt->vm_page_prot = (mpnt->vm_flags & VM_EXEC) ?
- PAGE_COPY_EXEC : PAGE_COPY;
- if ((ret = insert_vm_struct(mm, mpnt))) {
- up_write(&mm->mmap_sem);
- kmem_cache_free(vm_area_cachep, mpnt);
- return ret;
- }
- mm->stack_vm = mm->total_vm = vma_pages(mpnt);
- }
-
- for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
- struct page *page = bprm->page[i];
- if (page) {
- bprm->page[i] = NULL;
- install_arg_page(mpnt, page, stack_base);
- }
- stack_base += PAGE_SIZE;
- }
- up_write(&mm->mmap_sem);
-
- return 0;
-}
-EXPORT_SYMBOL(ia32_setup_arg_pages);
-
#ifdef CONFIG_SYSCTL
/* Register vsyscall32 into the ABI table */
#include <linux/sysctl.h>
fs/binfmt_elf.c
View filediff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index a27e42b..295cbaa 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -148,6 +148,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
elf_addr_t *elf_info;
int ei_index = 0;
struct task_struct *tsk = current;
+ struct vm_area_struct *vma;
/*
* If this architecture has a platform capability string, copy it
@@ -234,6 +235,15 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
sp = (elf_addr_t __user *)bprm->p;
#endif
+
+ /*
+ * Grow the stack manually; some architectures have a limit on how
+ * far ahead a user-space access may be in order to grow the stack.
+ */
+ vma = find_extend_vma(current->mm, bprm->p);
+ if (!vma)
+ return -EFAULT;
+
/* Now, let's put argc (and argv, envp if appropriate) on the stack */
if (__put_user(argc, sp++))
return -EFAULT;
@@ -254,8 +264,8 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
size_t len;
if (__put_user((elf_addr_t)p, argv++))
return -EFAULT;
- len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
- if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
+ len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
+ if (!len || len > MAX_ARG_STRLEN)
return 0;
p += len;
}
@@ -266,8 +276,8 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
size_t len;
if (__put_user((elf_addr_t)p, envp++))
return -EFAULT;
- len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
- if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
+ len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
+ if (!len || len > MAX_ARG_STRLEN)
return 0;
p += len;
}
@@ -826,10 +836,6 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
}
/* OK, This is the point of no return */
- current->mm->start_data = 0;
- current->mm->end_data = 0;
- current->mm->end_code = 0;
- current->mm->mmap = NULL;
current->flags &= ~PF_FORKNOEXEC;
current->mm->def_flags = def_flags;
@@ -1051,9 +1057,13 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
compute_creds(bprm);
current->flags &= ~PF_FORKNOEXEC;
- create_elf_tables(bprm, &loc->elf_ex,
+ retval = create_elf_tables(bprm, &loc->elf_ex,
(interpreter_type == INTERPRETER_AOUT),
load_addr, interp_load_addr);
+ if (retval < 0) {
+ send_sig(SIGKILL, current, 0);
+ goto out;
+ }
/* N.B. passed_fileno might not be initialized? */
if (interpreter_type == INTERPRETER_AOUT)
current->mm->arg_start += strlen(passed_fileno) + 1;
fs/binfmt_elf_fdpic.c
View filediff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index 9d62fba..4739506 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -621,8 +621,8 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
p = (char __user *) current->mm->arg_start;
for (loop = bprm->argc; loop > 0; loop--) {
__put_user((elf_caddr_t) p, argv++);
- len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
- if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
+ len = strnlen_user(p, MAX_ARG_STRLEN);
+ if (!len || len > MAX_ARG_STRLEN)
return -EINVAL;
p += len;
}
@@ -633,8 +633,8 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
current->mm->env_start = (unsigned long) p;
for (loop = bprm->envc; loop > 0; loop--) {
__put_user((elf_caddr_t)(unsigned long) p, envp++);
- len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
- if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
+ len = strnlen_user(p, MAX_ARG_STRLEN);
+ if (!len || len > MAX_ARG_STRLEN)
return -EINVAL;
p += len;
}
fs/binfmt_misc.c
View filediff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index 330fd3f..42e94b3 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c
@@ -126,7 +126,9 @@ static int load_misc_binary(struct linux_binprm *bprm, struct pt_regs *regs)
goto _ret;
if (!(fmt->flags & MISC_FMT_PRESERVE_ARGV0)) {
- remove_arg_zero(bprm);
+ retval = remove_arg_zero(bprm);
+ if (retval)
+ goto _ret;
}
if (fmt->flags & MISC_FMT_OPEN_BINARY) {
fs/binfmt_script.c
View filediff --git a/fs/binfmt_script.c b/fs/binfmt_script.c
index 304c885..4d0e0f6 100644
--- a/fs/binfmt_script.c
+++ b/fs/binfmt_script.c
@@ -67,7 +67,9 @@ static int load_script(struct linux_binprm *bprm,struct pt_regs *regs)
* This is done in reverse order, because of how the
* user environment and arguments are stored.
*/
- remove_arg_zero(bprm);
+ retval = remove_arg_zero(bprm);
+ if (retval)
+ return retval;
retval = copy_strings_kernel(1, &bprm->interp, bprm);
if (retval < 0) return retval;
bprm->argc++;
fs/compat.c
View filediff --git a/fs/compat.c b/fs/compat.c
index 4db6216..15078ce 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -1257,6 +1257,7 @@ static int compat_copy_strings(int argc, compat_uptr_t __user *argv,
{
struct page *kmapped_page = NULL;
char *kaddr = NULL;
+ unsigned long kpos = 0;
int ret;
while (argc-- > 0) {
@@ -1265,92 +1266,84 @@ static int compat_copy_strings(int argc, compat_uptr_t __user *argv,
unsigned long pos;
if (get_user(str, argv+argc) ||
- !(len = strnlen_user(compat_ptr(str), bprm->p))) {
+ !(len = strnlen_user(compat_ptr(str), MAX_ARG_STRLEN))) {
ret = -EFAULT;
goto out;
}
- if (bprm->p < len) {
+ if (len > MAX_ARG_STRLEN) {
ret = -E2BIG;
goto out;
}
- bprm->p -= len;
- /* XXX: add architecture specific overflow check here. */
+ /* We're going to work our way backwords. */
pos = bprm->p;
+ str += len;
+ bprm->p -= len;
while (len > 0) {
- int i, new, err;
int offset, bytes_to_copy;
- struct page *page;
offset = pos % PAGE_SIZE;
- i = pos/PAGE_SIZE;
- page = bprm->page[i];
- new = 0;
- if (!page) {
- page = alloc_page(GFP_HIGHUSER);
- bprm->page[i] = page;
- if (!page) {
- ret = -ENOMEM;
+ if (offset == 0)
+ offset = PAGE_SIZE;
+
+ bytes_to_copy = offset;
+ if (bytes_to_copy > len)
+ bytes_to_copy = len;
+
+ offset -= bytes_to_copy;
+ pos -= bytes_to_copy;
+ str -= bytes_to_copy;
+ len -= bytes_to_copy;
+
+ if (!kmapped_page || kpos != (pos & PAGE_MASK)) {
+ struct page *page;
+
+#ifdef CONFIG_STACK_GROWSUP
+ ret = expand_stack_downwards(bprm->vma, pos);
+ if (ret < 0) {
+ /* We've exceed the stack rlimit. */
+ ret = -E2BIG;
+ goto out;
+ }
+#endif
+ ret = get_user_pages(current, bprm->mm, pos,
+ 1, 1, 1, &page, NULL);
+ if (ret <= 0) {
+ /* We've exceed the stack rlimit. */
+ ret = -E2BIG;
goto out;
}
- new = 1;
- }
- if (page != kmapped_page) {
- if (kmapped_page)
+ if (kmapped_page) {
+ flush_kernel_dcache_page(kmapped_page);
kunmap(kmapped_page);
+ put_page(kmapped_page);
+ }
kmapped_page = page;
kaddr = kmap(kmapped_page);
+ kpos = pos & PAGE_MASK;
+ flush_cache_page(bprm->vma, kpos,
+ page_to_pfn(kmapped_page));
}
- if (new && offset)
- memset(kaddr, 0, offset);
- bytes_to_copy = PAGE_SIZE - offset;
- if (bytes_to_copy > len) {
- bytes_to_copy = len;
- if (new)
- memset(kaddr+offset+len, 0,
- PAGE_SIZE-offset-len);
- }
- err = copy_from_user(kaddr+offset, compat_ptr(str),
- bytes_to_copy);
- if (err) {
+ if (copy_from_user(kaddr+offset, compat_ptr(str),
+ bytes_to_copy)) {
ret = -EFAULT;
goto out;
}
-
- pos += bytes_to_copy;
- str += bytes_to_copy;
- len -= bytes_to_copy;
}
}
ret = 0;
out:
- if (kmapped_page)
+ if (kmapped_page) {
+ flush_kernel_dcache_page(kmapped_page);
kunmap(kmapped_page);
- return ret;
-}
-
-#ifdef CONFIG_MMU
-
-#define free_arg_pages(bprm) do { } while (0)
-
-#else
-
-static inline void free_arg_pages(struct linux_binprm *bprm)
-{
- int i;
-
- for (i = 0; i < MAX_ARG_PAGES; i++) {
- if (bprm->page[i])
- __free_page(bprm->page[i]);
- bprm->page[i] = NULL;
+ put_page(kmapped_page);
}
+ return ret;
}
-#endif /* CONFIG_MMU */
-
/*
* compat_do_execve() is mostly a copy of do_execve(), with the exception
* that it processes 32 bit argv and envp pointers.
@@ -1363,7 +1356,6 @@ int compat_do_execve(char * filename,
struct linux_binprm *bprm;
struct file *file;
int retval;
- int i;
retval = -ENOMEM;
bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
@@ -1377,24 +1369,19 @@ int compat_do_execve(char * filename,
sched_exec();
- bprm->p = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *);
bprm->file = file;
bprm->filename = filename;
bprm->interp = filename;
- bprm->mm = mm_alloc();
- retval = -ENOMEM;
- if (!bprm->mm)
- goto out_file;
- retval = init_new_context(current, bprm->mm);
- if (retval < 0)
- goto out_mm;
+ retval = bprm_mm_init(bprm);
+ if (retval)
+ goto out_file;
- bprm->argc = compat_count(argv, bprm->p / sizeof(compat_uptr_t));
+ bprm->argc = compat_count(argv, MAX_ARG_STRINGS);
if ((retval = bprm->argc) < 0)
goto out_mm;
- bprm->envc = compat_count(envp, bprm->p / sizeof(compat_uptr_t));
+ bprm->envc = compat_count(envp, MAX_ARG_STRINGS);
if ((retval = bprm->envc) < 0)
goto out_mm;
@@ -1421,8 +1408,6 @@ int compat_do_execve(char * filename,
retval = search_binary_handler(bprm, regs);
if (retval >= 0) {
- free_arg_pages(bprm);
-
/* execve success */
security_bprm_free(bprm);
acct_update_integrals(current);
@@ -1431,19 +1416,12 @@ int compat_do_execve(char * filename,
}
out:
- /* Something went wrong, return the inode and free the argument pages*/
- for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
- struct page * page = bprm->page[i];
- if (page)
- __free_page(page);
- }
-
if (bprm->security)
security_bprm_free(bprm);
out_mm:
if (bprm->mm)
- mmdrop(bprm->mm);
+ mmput(bprm->mm);
out_file:
if (bprm->file) {
fs/exec.c
View filediff --git a/fs/exec.c b/fs/exec.c
index 2e3f795..498f2b3 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -54,6 +54,7 @@
#include <asm/uaccess.h>
#include <asm/mmu_context.h>
+#include <asm/tlb.h>
#ifdef CONFIG_KMOD
#include <linux/kmod.h>
@@ -178,6 +179,207 @@ exit:
goto out;
}
+#ifdef CONFIG_MMU
+
+static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
+ int write)
+{
+ struct page *page;
+ int ret;
+
+#ifdef CONFIG_STACK_GROWSUP
+ if (write) {
+ ret = expand_stack_downwards(bprm->vma, pos);
+ if (ret < 0)
+ return NULL;
+ }
+#endif
+ ret = get_user_pages(current, bprm->mm, pos,
+ 1, write, 1, &page, NULL);
+ if (ret <= 0)
+ return NULL;
+
+ if (write) {
+ struct rlimit *rlim = current->signal->rlim;
+ unsigned long size = bprm->vma->vm_end - bprm->vma->vm_start;
+
+ /*
+ * Limit to 1/4-th the stack size for the argv+env strings.
+ * This ensures that:
+ * - the remaining binfmt code will not run out of stack space,
+ * - the program will have a reasonable amount of stack left
+ * to work from.
+ */
+ if (size > rlim[RLIMIT_STACK].rlim_cur / 4) {
+ put_page(page);
+ return NULL;
+ }
+ }
+
+ return page;
+}
+
+static void put_arg_page(struct page *page)
+{
+ put_page(page);
+}
+
+static void free_arg_page(struct linux_binprm *bprm, int i)
+{
+}
+
+static void free_arg_pages(struct linux_binprm *bprm)
+{
+}
+
+static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos,
+ struct page *page)
+{
+ flush_cache_page(bprm->vma, pos, page_to_pfn(page));
+}
+
+static int __bprm_mm_init(struct linux_binprm *bprm)
+{
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include/linux/binfmts.h
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include/linux/mm.h
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kernel/auditsc.c
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mm/mmap.c
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mm/mprotect.c
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mm/mremap.c
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