From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
as it is, the logics in native io_submit(2) is "if asked for
more than LONG_MAX/sizeof(pointer) iocbs to submit, don't
bother with more than LONG_MAX/sizeof(pointer)" (i.e.
512M requests on 32bit and 1E requests on 64bit) while
compat io_submit(2) goes with "stop after the first
PAGE_SIZE/sizeof(pointer) iocbs", i.e. 1K or so. Which is
* inconsistent
* *way* too much in native case
* possibly too little in compat one
and
* wrong anyway, since the natural point where we
ought to stop bothering is ctx->nr_events
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/aio.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/fs/aio.c b/fs/aio.c
index f67b0847ecac..aa4071c98335 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1844,15 +1844,15 @@ SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr,
if (unlikely(nr < 0))
return -EINVAL;
- if (unlikely(nr > LONG_MAX/sizeof(*iocbpp)))
- nr = LONG_MAX/sizeof(*iocbpp);
-
ctx = lookup_ioctx(ctx_id);
if (unlikely(!ctx)) {
pr_debug("EINVAL: invalid context id\n");
return -EINVAL;
}
+ if (nr > ctx->nr_events)
+ nr = ctx->nr_events;
+
blk_start_plug(&plug);
for (i = 0; i < nr; i++) {
struct iocb __user *user_iocb;
@@ -1873,8 +1873,6 @@ SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr,
}
#ifdef CONFIG_COMPAT
-#define MAX_AIO_SUBMITS (PAGE_SIZE/sizeof(struct iocb *))
-
COMPAT_SYSCALL_DEFINE3(io_submit, compat_aio_context_t, ctx_id,
int, nr, compat_uptr_t __user *, iocbpp)
{
@@ -1886,9 +1884,6 @@ COMPAT_SYSCALL_DEFINE3(io_submit, compat_aio_context_t, ctx_id,
if (unlikely(nr < 0))
return -EINVAL;
- if (nr > MAX_AIO_SUBMITS)
- nr = MAX_AIO_SUBMITS;
-
ctx = lookup_ioctx(ctx_id);
if (unlikely(!ctx)) {
pr_debug("EINVAL: invalid context id\n");
--
2.11.0
