mm: remove more IS_ERR_VALUE abuses
The do_brk() and vm_brk() return value was "unsigned long" and returned
the starting address on success, and an error value on failure. The
reasons are entirely historical, and go back to it basically behaving
like the mmap() interface does.
However, nobody actually wanted that interface, and it causes totally
pointless IS_ERR_VALUE() confusion.
What every single caller actually wants is just the simpler integer
return of zero for success and negative error number on failure.
So just convert to that much clearer and more common calling convention,
and get rid of all the IS_ERR_VALUE() uses wrt vm_brk().
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c
index f5e737f..cb26f18 100644
--- a/arch/x86/ia32/ia32_aout.c
+++ b/arch/x86/ia32/ia32_aout.c
@@ -116,12 +116,12 @@
.min_coredump = PAGE_SIZE
};
-static unsigned long set_brk(unsigned long start, unsigned long end)
+static int set_brk(unsigned long start, unsigned long end)
{
start = PAGE_ALIGN(start);
end = PAGE_ALIGN(end);
if (end <= start)
- return start;
+ return 0;
return vm_brk(start, end - start);
}
@@ -321,7 +321,7 @@
error = vm_brk(text_addr & PAGE_MASK, map_size);
- if (error != (text_addr & PAGE_MASK))
+ if (error)
return error;
error = read_code(bprm->file, text_addr, 32,
@@ -350,7 +350,7 @@
if (!bprm->file->f_op->mmap || (fd_offset & ~PAGE_MASK) != 0) {
error = vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
- if (IS_ERR_VALUE(error))
+ if (error)
return error;
read_code(bprm->file, N_TXTADDR(ex), fd_offset,
@@ -378,7 +378,7 @@
beyond_if:
error = set_brk(current->mm->start_brk, current->mm->brk);
- if (IS_ERR_VALUE(error))
+ if (error)
return error;
set_binfmt(&aout_format);
@@ -441,7 +441,7 @@
}
#endif
retval = vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
- if (IS_ERR_VALUE(retval))
+ if (retval)
goto out;
read_code(file, start_addr, N_TXTOFF(ex),
@@ -461,9 +461,8 @@
len = PAGE_ALIGN(ex.a_text + ex.a_data);
bss = ex.a_text + ex.a_data + ex.a_bss;
if (bss > len) {
- error = vm_brk(start_addr + len, bss - len);
- retval = error;
- if (error != start_addr + len)
+ retval = vm_brk(start_addr + len, bss - len);
+ if (retval)
goto out;
}
retval = 0;
diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c
index 2fab9f1..64b331ae 100644
--- a/fs/binfmt_aout.c
+++ b/fs/binfmt_aout.c
@@ -127,11 +127,8 @@
{
start = PAGE_ALIGN(start);
end = PAGE_ALIGN(end);
- if (end > start) {
- unsigned long addr;
- addr = vm_brk(start, end - start);
- if (BAD_ADDR(addr))
- return addr;
+ if (end > start)
+ return vm_brk(start, end - start);
}
return 0;
}
@@ -275,7 +272,7 @@
map_size = ex.a_text+ex.a_data;
#endif
error = vm_brk(text_addr & PAGE_MASK, map_size);
- if (error != (text_addr & PAGE_MASK))
+ if (error)
return error;
error = read_code(bprm->file, text_addr, pos,
@@ -298,7 +295,7 @@
if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) {
error = vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
- if (IS_ERR_VALUE(error))
+ if (error)
return error;
read_code(bprm->file, N_TXTADDR(ex), fd_offset,
@@ -382,7 +379,7 @@
file);
}
retval = vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
- if (IS_ERR_VALUE(retval))
+ if (retval)
goto out;
read_code(file, start_addr, N_TXTOFF(ex),
@@ -402,9 +399,8 @@
len = PAGE_ALIGN(ex.a_text + ex.a_data);
bss = ex.a_text + ex.a_data + ex.a_bss;
if (bss > len) {
- error = vm_brk(start_addr + len, bss - len);
- retval = error;
- if (error != start_addr + len)
+ retval = vm_brk(start_addr + len, bss - len);
+ if (retval)
goto out;
}
retval = 0;
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 938fc4e..e158b22 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -96,10 +96,9 @@
start = ELF_PAGEALIGN(start);
end = ELF_PAGEALIGN(end);
if (end > start) {
- unsigned long addr;
- addr = vm_brk(start, end - start);
- if (BAD_ADDR(addr))
- return addr;
+ int error = vm_brk(start, end - start);
+ if (error)
+ return error;
}
current->mm->start_brk = current->mm->brk = end;
return 0;
@@ -629,7 +628,7 @@
/* Map the last of the bss segment */
error = vm_brk(elf_bss, last_bss - elf_bss);
- if (BAD_ADDR(error))
+ if (error)
goto out;
}
@@ -1178,7 +1177,7 @@
bss = eppnt->p_memsz + eppnt->p_vaddr;
if (bss > len) {
error = vm_brk(len, bss - len);
- if (BAD_ADDR(error))
+ if (error)
goto out_free_ph;
}
error = 0;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a00ec81..5df5feb 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2018,7 +2018,7 @@
#endif
/* These take the mm semaphore themselves */
-extern unsigned long __must_check vm_brk(unsigned long, unsigned long);
+extern int __must_check vm_brk(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 d3d9a94..de2c176 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -168,7 +168,7 @@
return next;
}
-static unsigned long do_brk(unsigned long addr, unsigned long len);
+static int do_brk(unsigned long addr, unsigned long len);
SYSCALL_DEFINE1(brk, unsigned long, brk)
{
@@ -224,7 +224,7 @@
goto out;
/* Ok, looks good - let it rip. */
- if (do_brk(oldbrk, newbrk-oldbrk) != oldbrk)
+ if (do_brk(oldbrk, newbrk-oldbrk) < 0)
goto out;
set_brk:
@@ -2625,7 +2625,7 @@
* anonymous maps. eventually we may be able to do some
* brk-specific accounting here.
*/
-static unsigned long do_brk(unsigned long addr, unsigned long len)
+static int do_brk(unsigned long addr, unsigned long len)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma, *prev;
@@ -2636,7 +2636,7 @@
len = PAGE_ALIGN(len);
if (!len)
- return addr;
+ return 0;
flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
@@ -2703,13 +2703,13 @@
if (flags & VM_LOCKED)
mm->locked_vm += (len >> PAGE_SHIFT);
vma->vm_flags |= VM_SOFTDIRTY;
- return addr;
+ return 0;
}
-unsigned long vm_brk(unsigned long addr, unsigned long len)
+int vm_brk(unsigned long addr, unsigned long len)
{
struct mm_struct *mm = current->mm;
- unsigned long ret;
+ int ret;
bool populate;
if (down_write_killable(&mm->mmap_sem))
@@ -2718,7 +2718,7 @@
ret = do_brk(addr, len);
populate = ((mm->def_flags & VM_LOCKED) != 0);
up_write(&mm->mmap_sem);
- if (populate)
+ if (populate && !ret)
mm_populate(addr, len);
return ret;
}
diff --git a/mm/nommu.c b/mm/nommu.c
index c8bd59a..c2e588802 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1682,7 +1682,7 @@
}
}
-unsigned long vm_brk(unsigned long addr, unsigned long len)
+int vm_brk(unsigned long addr, unsigned long len)
{
return -ENOMEM;
}
