Re: [PATCH] Fix blktrace setup 32-bit ioctl on 64-bit kernels

Jens Axboe
2007-10-02T09:27:18Z

Hi Arnd,

Updated patch below. I kept the code in compat_ioctl.c, to me it seems
like the cleanest approach. I need the BLKTRACESETUP32 define both in
compat_ioctl.c and blktrace.c if I move it, and I need to hard-core the
struct size or define it in both places. And guard the code in
blktrace.c with an ifdef for CONFIG_COMPAT. Not pretty, imho.

I haven't tested this one yet, but at least it compiles and the sizing
seems right. The u16 padding was an artifact of the
__attribute__((packed)) so that could be removed.

diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index 5a5b711..54162e5 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -2052,6 +2052,44 @@ static int raw_ioctl(unsigned fd, unsigned cmd, unsigned long arg)
}
return ret;
}
+
+struct blk_user_trace_setup32 {
+ char name[32];
+ u16 act_mask;
+ u32 buf_size;
+ u32 buf_nr;
+ compat_u64 start_lba;
+ compat_u64 end_lba;
+ u32 pid;
+};
+
+#define BLKTRACESETUP32 _IOWR(0x12,115,struct blk_user_trace_setup32)
+
+static int blktrace32_setup(int fd, unsigned cmd, unsigned long arg)
+{
+ struct blk_user_trace_setup __user *buts = compat_alloc_user_space(sizeof(*buts));
+ struct blk_user_trace_setup32 __user *buts32 = compat_ptr(arg);
+ int err;
+
+ if (copy_in_user(&buts->name, &buts32->name, 32) ||
+ get_user(buts->act_mask, &buts32->act_mask) ||
+ get_user(buts->buf_size, &buts32->buf_size) ||
+ get_user(buts->buf_nr, &buts32->buf_nr) ||
+ get_user(buts->start_lba, &buts32->start_lba) ||
+ get_user(buts->end_lba, &buts32->end_lba) ||
+ get_user(buts->pid, &buts32->pid))
+ return -EFAULT;
+
+ err = sys_ioctl(fd, cmd, (unsigned long) buts);
+ if (err)
+ return err;
+
+ if (copy_to_user(&buts32->name, &buts->name, 32))
+ return -EFAULT;
+
+ return err;
+}
+
#endif /* CONFIG_BLOCK */

struct serial_struct32 {
@@ -2555,7 +2593,7 @@ COMPATIBLE_IOCTL(BLKSECTSET)
COMPATIBLE_IOCTL(BLKSSZGET)
COMPATIBLE_IOCTL(BLKTRACESTART)
COMPATIBLE_IOCTL(BLKTRACESTOP)
-COMPATIBLE_IOCTL(BLKTRACESETUP)
+HANDLE_IOCTL(BLKTRACESETUP32, blktrace32_setup)
COMPATIBLE_IOCTL(BLKTRACETEARDOWN)
ULONG_IOCTL(BLKRASET)
ULONG_IOCTL(BLKFRASET)

--
Jens Axboe