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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-12 18:44:26 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-13 12:00:23 -0800 |
| commit | 02042a4cf472a1362e39da72a1d992d59a58a0ab (patch) | |
| tree | beb9203359e472201a326251d937bf7d750beb27 /drivers/tty/serial/8250/8250_pci.c | |
| parent | 4a37c0fcf5d403e7d9f5309ea970ea3c9074b5d8 (diff) | |
| download | linux-02042a4cf472a1362e39da72a1d992d59a58a0ab.tar.gz | |
serial: 8250_pci: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200213004426.GA7886@embeddedor.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/8250/8250_pci.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_pci.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c index 939685fed396..0804469ff052 100644 --- a/drivers/tty/serial/8250/8250_pci.c +++ b/drivers/tty/serial/8250/8250_pci.c @@ -53,7 +53,7 @@ struct serial_private { unsigned int nr; struct pci_serial_quirk *quirk; const struct pciserial_board *board; - int line[0]; + int line[]; }; static const struct pci_device_id pci_use_msi[] = { |