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-rw-r--r--arch/powerpc/include/asm/page.h4
-rw-r--r--fs/binfmt_elf.c30
-rw-r--r--include/linux/mm.h1
-rw-r--r--mm/mmap.c24
4 files changed, 45 insertions, 14 deletions
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 47120bf2670c..2a32483c7b6c 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -230,7 +230,9 @@ extern long long virt_phys_offset;
* and needs to be executable. This means the whole heap ends
* up being executable.
*/
-#define VM_DATA_DEFAULT_FLAGS32 (VM_READ | VM_WRITE | VM_EXEC | \
+#define VM_DATA_DEFAULT_FLAGS32 \
+ (((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \
+ VM_READ | VM_WRITE | \
VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
#define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index e7bf01373bc4..443a6f537d56 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -91,12 +91,18 @@ static struct linux_binfmt elf_format = {
#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
-static int set_brk(unsigned long start, unsigned long end)
+static int set_brk(unsigned long start, unsigned long end, int prot)
{
start = ELF_PAGEALIGN(start);
end = ELF_PAGEALIGN(end);
if (end > start) {
- int error = vm_brk(start, end - start);
+ /*
+ * Map the last of the bss segment.
+ * If the header is requesting these pages to be
+ * executable, honour that (ppc32 needs this).
+ */
+ int error = vm_brk_flags(start, end - start,
+ prot & PROT_EXEC ? VM_EXEC : 0);
if (error)
return error;
}
@@ -524,6 +530,7 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
unsigned long load_addr = 0;
int load_addr_set = 0;
unsigned long last_bss = 0, elf_bss = 0;
+ int bss_prot = 0;
unsigned long error = ~0UL;
unsigned long total_size;
int i;
@@ -606,8 +613,10 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
* elf_bss and last_bss is the bss section.
*/
k = load_addr + eppnt->p_vaddr + eppnt->p_memsz;
- if (k > last_bss)
+ if (k > last_bss) {
last_bss = k;
+ bss_prot = elf_prot;
+ }
}
}
@@ -623,13 +632,14 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
/*
* Next, align both the file and mem bss up to the page size,
* since this is where elf_bss was just zeroed up to, and where
- * last_bss will end after the vm_brk() below.
+ * last_bss will end after the vm_brk_flags() below.
*/
elf_bss = ELF_PAGEALIGN(elf_bss);
last_bss = ELF_PAGEALIGN(last_bss);
/* Finally, if there is still more bss to allocate, do it. */
if (last_bss > elf_bss) {
- error = vm_brk(elf_bss, last_bss - elf_bss);
+ error = vm_brk_flags(elf_bss, last_bss - elf_bss,
+ bss_prot & PROT_EXEC ? VM_EXEC : 0);
if (error)
goto out;
}
@@ -674,6 +684,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
unsigned long error;
struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata = NULL;
unsigned long elf_bss, elf_brk;
+ int bss_prot = 0;
int retval, i;
unsigned long elf_entry;
unsigned long interp_load_addr = 0;
@@ -882,7 +893,8 @@ static int load_elf_binary(struct linux_binprm *bprm)
before this one. Map anonymous pages, if needed,
and clear the area. */
retval = set_brk(elf_bss + load_bias,
- elf_brk + load_bias);
+ elf_brk + load_bias,
+ bss_prot);
if (retval)
goto out_free_dentry;
nbyte = ELF_PAGEOFFSET(elf_bss);
@@ -976,8 +988,10 @@ static int load_elf_binary(struct linux_binprm *bprm)
if (end_data < k)
end_data = k;
k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
- if (k > elf_brk)
+ if (k > elf_brk) {
+ bss_prot = elf_prot;
elf_brk = k;
+ }
}
loc->elf_ex.e_entry += load_bias;
@@ -993,7 +1007,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
* mapping in the interpreter, to make sure it doesn't wind
* up getting placed where the bss needs to go.
*/
- retval = set_brk(elf_bss, elf_brk);
+ retval = set_brk(elf_bss, elf_brk, bss_prot);
if (retval)
goto out_free_dentry;
if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
diff --git a/include/linux/mm.h b/include/linux/mm.h
index bb997493e15d..dae6f58d67c8 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2083,6 +2083,7 @@ static inline void mm_populate(unsigned long addr, unsigned long len) {}
/* These take the mm semaphore themselves */
extern int __must_check vm_brk(unsigned long, unsigned long);
+extern int __must_check vm_brk_flags(unsigned long, unsigned long, unsigned long);
extern int vm_munmap(unsigned long, size_t);
extern unsigned long __must_check vm_mmap(struct file *, unsigned long,
unsigned long, unsigned long,
diff --git a/mm/mmap.c b/mm/mmap.c
index dc4291dcc99b..b729084eea90 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2806,11 +2806,11 @@ static inline void verify_mm_writelocked(struct mm_struct *mm)
* anonymous maps. eventually we may be able to do some
* brk-specific accounting here.
*/
-static int do_brk(unsigned long addr, unsigned long request)
+static int do_brk_flags(unsigned long addr, unsigned long request, unsigned long flags)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma, *prev;
- unsigned long flags, len;
+ unsigned long len;
struct rb_node **rb_link, *rb_parent;
pgoff_t pgoff = addr >> PAGE_SHIFT;
int error;
@@ -2821,7 +2821,10 @@ static int do_brk(unsigned long addr, unsigned long request)
if (!len)
return 0;
- flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
+ /* Until we need other flags, refuse anything except VM_EXEC. */
+ if ((flags & (~VM_EXEC)) != 0)
+ return -EINVAL;
+ flags |= VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
error = get_unmapped_area(NULL, addr, len, 0, MAP_FIXED);
if (offset_in_page(error))
@@ -2889,7 +2892,12 @@ out:
return 0;
}
-int vm_brk(unsigned long addr, unsigned long len)
+static int do_brk(unsigned long addr, unsigned long len)
+{
+ return do_brk_flags(addr, len, 0);
+}
+
+int vm_brk_flags(unsigned long addr, unsigned long len, unsigned long flags)
{
struct mm_struct *mm = current->mm;
int ret;
@@ -2898,13 +2906,19 @@ int vm_brk(unsigned long addr, unsigned long len)
if (down_write_killable(&mm->mmap_sem))
return -EINTR;
- ret = do_brk(addr, len);
+ ret = do_brk_flags(addr, len, flags);
populate = ((mm->def_flags & VM_LOCKED) != 0);
up_write(&mm->mmap_sem);
if (populate && !ret)
mm_populate(addr, len);
return ret;
}
+EXPORT_SYMBOL(vm_brk_flags);
+
+int vm_brk(unsigned long addr, unsigned long len)
+{
+ return vm_brk_flags(addr, len, 0);
+}
EXPORT_SYMBOL(vm_brk);
/* Release all mmaps. */
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-20 20:36:09 +0000