[Qemu-devel] [PATCH v2] linux-user: ioctl() command type is int

[Laurent Vivier]

When executing a 64bit target chroot on 64bit host,
the ioctl() command can mismatch.

It seems the previous commit doesn't solve the problem in
my case:

        9c6bf9c7 linux-user: Fix ioctl cmd type mismatch on 64-bit targets

For example, a ppc64 chroot on an x86_64 host:

bash-4.3# ls
Unsupported ioctl: cmd=0x80087467
Unsupported ioctl: cmd=0x802c7415

The origin of the problem is in syscall.c:do_ioctl().

        static abi_long do_ioctl(int fd, abi_long cmd, abi_long arg)

In this case (ppc64) abi_long is long (on the x86_64), and

    cmd = 0x0000000080087467

then
        if (ie->target_cmd == cmd)

target_cmd is int, so target_cmd = 0x80087467
and to compare an int with a long, the sign is extended to 64bit,
so the comparison is:

        if (0xffffffff80087467 == 0x0000000080087467)

which doesn't match whereas it should.

This patch uses int in the case of the target command type
instead of abi_long.

Signed-off-by: Laurent Vivier <address@hidden>
---
v2: Don't modify IOCTLEntry type (useless and introduce clang errors)
 linux-user/syscall.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index b98b7e7..5a280c3 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -3645,7 +3645,7 @@ enum {
 typedef struct IOCTLEntry IOCTLEntry;
 
 typedef abi_long do_ioctl_fn(const IOCTLEntry *ie, uint8_t *buf_temp,
-                             int fd, abi_long cmd, abi_long arg);
+                             int fd, int cmd, abi_long arg);
 
 struct IOCTLEntry {
     int target_cmd;
@@ -3671,7 +3671,7 @@ struct IOCTLEntry {
                             / sizeof(struct fiemap_extent))
 
 static abi_long do_ioctl_fs_ioc_fiemap(const IOCTLEntry *ie, uint8_t *buf_temp,
-                                       int fd, abi_long cmd, abi_long arg)
+                                       int fd, int cmd, abi_long arg)
 {
     /* The parameter for this ioctl is a struct fiemap followed
      * by an array of struct fiemap_extent whose size is set
@@ -3752,7 +3752,7 @@ static abi_long do_ioctl_fs_ioc_fiemap(const IOCTLEntry 
*ie, uint8_t *buf_temp,
 #endif
 
 static abi_long do_ioctl_ifconf(const IOCTLEntry *ie, uint8_t *buf_temp,
-                                int fd, abi_long cmd, abi_long arg)
+                                int fd, int cmd, abi_long arg)
 {
     const argtype *arg_type = ie->arg_type;
     int target_size;
@@ -3846,7 +3846,7 @@ static abi_long do_ioctl_ifconf(const IOCTLEntry *ie, 
uint8_t *buf_temp,
 }
 
 static abi_long do_ioctl_dm(const IOCTLEntry *ie, uint8_t *buf_temp, int fd,
-                            abi_long cmd, abi_long arg)
+                            int cmd, abi_long arg)
 {
     void *argptr;
     struct dm_ioctl *host_dm;
@@ -4071,7 +4071,7 @@ out:
 }
 
 static abi_long do_ioctl_blkpg(const IOCTLEntry *ie, uint8_t *buf_temp, int fd,
-                               abi_long cmd, abi_long arg)
+                               int cmd, abi_long arg)
 {
     void *argptr;
     int target_size;
@@ -4124,7 +4124,7 @@ out:
 }
 
 static abi_long do_ioctl_rt(const IOCTLEntry *ie, uint8_t *buf_temp,
-                                int fd, abi_long cmd, abi_long arg)
+                                int fd, int cmd, abi_long arg)
 {
     const argtype *arg_type = ie->arg_type;
     const StructEntry *se;
@@ -4187,7 +4187,7 @@ static abi_long do_ioctl_rt(const IOCTLEntry *ie, uint8_t 
*buf_temp,
 }
 
 static abi_long do_ioctl_kdsigaccept(const IOCTLEntry *ie, uint8_t *buf_temp,
-                                     int fd, abi_long cmd, abi_long arg)
+                                     int fd, int cmd, abi_long arg)
 {
     int sig = target_to_host_signal(arg);
     return get_errno(ioctl(fd, ie->host_cmd, sig));
@@ -4204,7 +4204,7 @@ static IOCTLEntry ioctl_entries[] = {
 
 /* ??? Implement proper locking for ioctls.  */
 /* do_ioctl() Must return target values and target errnos. */
-static abi_long do_ioctl(int fd, abi_long cmd, abi_long arg)
+static abi_long do_ioctl(int fd, int cmd, abi_long arg)
 {
     const IOCTLEntry *ie;
     const argtype *arg_type;
-- 
2.4.3