Mercurial > sdl-ios-xcode
diff src/joystick/linux/SDL_sysjoystick.c @ 3404:c9dcc73f6a36
Fixed bug #853
Ludwig Nussel 2009-10-18 05:34:18 PDT
src/joystick/linux/SDL_sysjoystick.c has some problems:
- test_bit() might break with strict aliasing
- test_bit() assumes array is Uint32 but its actually "unsigned long"
on 64bit systems sizeof(long) != sizeof(Uint32).
- the keybit array is too small
- the arrays are unitialized so the number of
detected buttons is quite random
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Sun, 18 Oct 2009 16:14:35 +0000 |
| parents | 11c079bb52a8 |
| children | 493f252a455c |
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--- a/src/joystick/linux/SDL_sysjoystick.c Sat Oct 17 23:29:52 2009 +0000 +++ b/src/joystick/linux/SDL_sysjoystick.c Sun Oct 18 16:14:35 2009 +0000 @@ -366,14 +366,15 @@ #if SDL_INPUT_LINUXEV #define test_bit(nr, addr) \ - (((1UL << ((nr) & 31)) & (((const Uint32 *) addr)[(nr) >> 5])) != 0) + (((1UL << ((nr) % (sizeof(long) * 8))) & ((addr)[(nr) / (sizeof(long) * 8)])) != 0) +#define NBITS(x) ((((x)-1)/(sizeof(long) * 8))+1) static int EV_IsJoystick(int fd) { - unsigned long evbit[40]; - unsigned long keybit[40]; - unsigned long absbit[40]; + unsigned long evbit[NBITS(EV_MAX)] = { 0 }; + unsigned long keybit[NBITS(KEY_MAX)] = { 0 }; + unsigned long absbit[NBITS(ABS_MAX)] = { 0 }; if ((ioctl(fd, EVIOCGBIT(0, sizeof(evbit)), evbit) < 0) || (ioctl(fd, EVIOCGBIT(EV_KEY, sizeof(keybit)), keybit) < 0) || @@ -664,9 +665,9 @@ EV_ConfigJoystick(SDL_Joystick * joystick, int fd) { int i, t; - unsigned long keybit[40]; - unsigned long absbit[40]; - unsigned long relbit[40]; + unsigned long keybit[NBITS(KEY_MAX)] = { 0 }; + unsigned long absbit[NBITS(ABS_MAX)] = { 0 }; + unsigned long relbit[NBITS(REL_MAX)] = { 0 }; /* See if this device uses the new unified event API */ if ((ioctl(fd, EVIOCGBIT(EV_KEY, sizeof(keybit)), keybit) >= 0) &&