Messages in this thread Patch in this message | | | Subject | [PATCH] Adjust sysrq_register_handler() to avoid an array subscript warning | From | David Howells <> | Date | Tue, 28 Apr 2015 10:49:39 +0100 |
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sysrq_register_handler() iterates over platform_sysrq_reset_seq[] using ARRAY_SIZE() on sysrq_reset_seq[] as a limit (indeed, the platform array is expected to be shorter). gcc-5 spots the potential dereference beyond the end of the array and issues the following warnings:
CC drivers/tty/sysrq.o ../drivers/tty/sysrq.c: In function 'sysrq_init': ../drivers/tty/sysrq.c:958:33: warning: array subscript is above array bounds [-Warray-bounds] key = platform_sysrq_reset_seq[i]; ^ ../drivers/tty/sysrq.c: In function 'sysrq_toggle_support': ../drivers/tty/sysrq.c:958:33: warning: array subscript is above array bounds [-Warray-bounds] key = platform_sysrq_reset_seq[i]; ^
Since the platform_sysrq_reset_seq[] array is apparently meant to be terminated rather than being fixed length, use a pointer to iterate over it instead.
One further note: Should platform_sysrq_reset_seq[] be const?
Signed-off-by: David Howells <dhowells@redhat.com> ---
drivers/tty/sysrq.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c index 843f2cdc280b..431af8b6bdb7 100644 --- a/drivers/tty/sysrq.c +++ b/drivers/tty/sysrq.c @@ -949,13 +949,14 @@ static bool sysrq_handler_registered; static inline void sysrq_register_handler(void) { + const unsigned short *p = platform_sysrq_reset_seq; unsigned short key; int error; int i; /* First check if a __weak interface was instantiated. */ for (i = 0; i < ARRAY_SIZE(sysrq_reset_seq); i++) { - key = platform_sysrq_reset_seq[i]; + key = *p++; if (key == KEY_RESERVED || key > KEY_MAX) break;
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