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author | Keir Fraser <keir.fraser@citrix.com> | 2010-07-02 18:53:10 +0100 |
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committer | Keir Fraser <keir.fraser@citrix.com> | 2010-07-02 18:53:10 +0100 |
commit | 43b0124af6b67ca65a1b4e82cf6b22b6d56119f8 (patch) | |
tree | 928737ddd97474f5a5b879bf2ceed5aba33b46e5 /xen/common/trace.c | |
parent | 79fdc7a419bd9f4e46b0d24549e6a6ee894d19d9 (diff) | |
download | xen-43b0124af6b67ca65a1b4e82cf6b22b6d56119f8.tar.gz xen-43b0124af6b67ca65a1b4e82cf6b22b6d56119f8.tar.bz2 xen-43b0124af6b67ca65a1b4e82cf6b22b6d56119f8.zip |
trace: improve check_tbuf_size()
It didn't consider the case of the incoming size not allowing for the
2*data_size range for t_buf->{prod,cons}
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Diffstat (limited to 'xen/common/trace.c')
-rw-r--r-- | xen/common/trace.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/xen/common/trace.c b/xen/common/trace.c index caf9b7f621..8d4f02a458 100644 --- a/xen/common/trace.c +++ b/xen/common/trace.c @@ -92,11 +92,19 @@ static void calc_tinfo_first_offset(void) /** * check_tbuf_size - check to make sure that the proposed size will fit - * in the currently sized struct t_info. + * in the currently sized struct t_info and allows prod and cons to + * reach double the value without overflow. */ -static inline int check_tbuf_size(int size) +static int check_tbuf_size(u32 pages) { - return (num_online_cpus() * size + t_info_first_offset) > (T_INFO_SIZE / sizeof(uint32_t)); + struct t_buf dummy; + typeof(dummy.prod) size; + + size = ((typeof(dummy.prod))pages) * PAGE_SIZE; + + return (size / PAGE_SIZE != pages) + || (size + size < size) + || (num_online_cpus() * pages + t_info_first_offset > T_INFO_SIZE / sizeof(uint32_t)); } /** |