sdp: move histogram allocation from stack to heap

- Cause a kernel crash when accessing /proc/net/sdpstats on RH6

Signed-off-by: Amir Vadai <amirv@mellanox.co.il>

diff --git a/drivers/infiniband/ulp/sdp/sdp_proc.c b/drivers/infiniband/ulp/sdp/sdp_proc.c
index 33f66b6a2393f358903df839b230e011db7181f9..d88d0d0747b21a4d48bb23cfb9c01076cd4677b0 100644 (file)
--- a/drivers/infiniband/ulp/sdp/sdp_proc.c
+++ b/drivers/infiniband/ulp/sdp/sdp_proc.c
@@ -33,6 +33,7 @@
 #include <linux/proc_fs.h>
 #include <linux/debugfs.h>
 #include <rdma/sdp_socket.h>
+#include <linux/vmalloc.h>
 #include "sdp.h"
 
 #ifdef CONFIG_PROC_FS
@@ -284,17 +285,15 @@ static void sdpstats_seq_hist(struct seq_file *seq, char *str, u32 *h, int n,
 })
 
 #define __sdpstats_seq_hist(seq, msg, hist, is_log) ({         \
-       u32 tmp_hist[SDPSTATS_MAX_HIST_SIZE];                   \
        int hist_len = ARRAY_SIZE(__get_cpu_var(sdpstats).hist);\
-       memset(tmp_hist, 0, sizeof(tmp_hist));                  \
-       SDPSTATS_HIST_GET(hist, hist_len, tmp_hist);    \
-       sdpstats_seq_hist(seq, msg, tmp_hist, hist_len, is_log);\
+       memset(h, 0, sizeof(*h) * h_len);                       \
+       SDPSTATS_HIST_GET(hist, hist_len, h);   \
+       sdpstats_seq_hist(seq, msg, h, hist_len, is_log);\
 })
 
 #define __sdpstats_seq_hist_pcpu(seq, msg, hist) ({            \
-       u32 h[NR_CPUS];                                         \
        unsigned int __i;                                       \
-       memset(h, 0, sizeof(h));                                \
+       memset(h, 0, sizeof(*h) * h_len);                               \
        for_each_possible_cpu(__i) {                            \
                h[__i] = per_cpu(sdpstats, __i).hist;           \
        }                                                       \
@@ -304,6 +303,11 @@ static void sdpstats_seq_hist(struct seq_file *seq, char *str, u32 *h, int n,
 static int sdpstats_seq_show(struct seq_file *seq, void *v)
 {
        int i;
+       size_t h_len = max(NR_CPUS, SDPSTATS_MAX_HIST_SIZE);
+       u32 *h;
+
+       if (!(h = vmalloc(h_len * sizeof(*h))))
+               return -ENOMEM;
 
        seq_printf(seq, "SDP statistics:\n");
 
@@ -384,6 +388,8 @@ static int sdpstats_seq_show(struct seq_file *seq, void *v)
        __sdpstats_seq_hist_pcpu(seq, "CPU rx_wq", rx_wq);
        __sdpstats_seq_hist_pcpu(seq, "CPU tx_irq", tx_int_count);
 
+       vfree(h);
+
        return 0;
 }