[CCID2]: Allocation in atomic context and simplify interface
1.) This fixes the following bug reported in syslog:
[ 4039.051658] BUG: sleeping function called from invalid context at /usr/src/davem-2.6/mm/slab.c:3032
[ 4039.051668] in_atomic():1, irqs_disabled():0
[ 4039.051670] INFO: lockdep is turned off.
[ 4039.051674] [<c0104c0f>] show_trace_log_lvl+0x1a/0x30
[ 4039.051687] [<c0104d4d>] show_trace+0x12/0x14
[ 4039.051691] [<c0104d65>] dump_stack+0x16/0x18
[ 4039.051695] [<c011371e>] __might_sleep+0xaf/0xbe
[ 4039.051700] [<c0157b66>] __kmalloc+0xb1/0xd0
[ 4039.051706] [<f090416f>] ccid2_hc_tx_alloc_seq+0x35/0xc3 [dccp_ccid2]
[ 4039.051717] [<f09048d6>] ccid2_hc_tx_packet_sent+0x27f/0x2d9 [dccp_ccid2]
[ 4039.051723] [<f085486b>] dccp_write_xmit+0x1eb/0x338 [dccp]
[ 4039.051741] [<f085603d>] dccp_sendmsg+0x113/0x18f [dccp]
[ 4039.051750] [<c03907fc>] inet_sendmsg+0x2e/0x4c
[ 4039.051758] [<c033a47d>] sock_aio_write+0xd5/0x107
[ 4039.051766] [<c015abc1>] do_sync_write+0xcd/0x11c
[ 4039.051772] [<c015b296>] vfs_write+0x118/0x11f
[ 4039.051840] [<c015b932>] sys_write+0x3d/0x64
[ 4039.051845] [<c0103e7c>] syscall_call+0x7/0xb
[ 4039.051848] =======================
The problem was that GFP_KERNEL was used; fixed by using gfp_any().
2.) While at it, the interface of ccid2_hc_tx_alloc_seq() has been simplified:
* ccid2_hc_tx_alloc_seq() is always called with an argument of CCID2_SEQBUF_LEN;
* other code - ccid2_hc_tx_check_sanity() - even depends on the assumption that
ccid2_hc_tx_alloc_seq() has been called with this particular size;
* passing the `gfp_t' argument to ccid2_hc_tx_alloc_seq() is redundant with gfp_any().
Signed-off-by: Gerrit Renker <gerrit@xxxxxxxxxxxxxx>
---
net/dccp/ccids/ccid2.c | 19 +++++++++----------
1 file changed, 9 insertions(+), 10 deletions(-)
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -83,8 +83,7 @@ static void ccid2_hc_tx_check_sanity(con
#define ccid2_hc_tx_check_sanity(hctx)
#endif
-static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx, int num,
- gfp_t gfp)
+static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx)
{
struct ccid2_seq *seqp;
int i;
@@ -95,16 +94,16 @@ static int ccid2_hc_tx_alloc_seq(struct
return -ENOMEM;
/* allocate buffer and initialize linked list */
- seqp = kmalloc(sizeof(*seqp) * num, gfp);
+ seqp = kmalloc(CCID2_SEQBUF_LEN * sizeof(struct ccid2_seq), gfp_any());
if (seqp == NULL)
return -ENOMEM;
- for (i = 0; i < (num - 1); i++) {
+ for (i = 0; i < (CCID2_SEQBUF_LEN - 1); i++) {
seqp[i].ccid2s_next = &seqp[i + 1];
seqp[i + 1].ccid2s_prev = &seqp[i];
}
- seqp[num - 1].ccid2s_next = seqp;
- seqp->ccid2s_prev = &seqp[num - 1];
+ seqp[CCID2_SEQBUF_LEN - 1].ccid2s_next = seqp;
+ seqp->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1];
/* This is the first allocation. Initiate the head and tail. */
if (hctx->ccid2hctx_seqbufc == 0)
@@ -114,8 +113,8 @@ static int ccid2_hc_tx_alloc_seq(struct
hctx->ccid2hctx_seqh->ccid2s_next = seqp;
seqp->ccid2s_prev = hctx->ccid2hctx_seqh;
- hctx->ccid2hctx_seqt->ccid2s_prev = &seqp[num - 1];
- seqp[num - 1].ccid2s_next = hctx->ccid2hctx_seqt;
+ hctx->ccid2hctx_seqt->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1];
+ seqp[CCID2_SEQBUF_LEN - 1].ccid2s_next = hctx->ccid2hctx_seqt;
}
/* store the original pointer to the buffer so we can free it */
@@ -298,7 +297,7 @@ static void ccid2_hc_tx_packet_sent(stru
int rc;
ccid2_pr_debug("allocating more space in history\n");
- rc = ccid2_hc_tx_alloc_seq(hctx, CCID2_SEQBUF_LEN, GFP_KERNEL);
+ rc = ccid2_hc_tx_alloc_seq(hctx);
BUG_ON(rc); /* XXX what do we do? */
next = hctx->ccid2hctx_seqh->ccid2s_next;
@@ -771,7 +770,7 @@ static int ccid2_hc_tx_init(struct ccid
hctx->ccid2hctx_seqbufc = 0;
/* XXX init ~ to window size... */
- if (ccid2_hc_tx_alloc_seq(hctx, CCID2_SEQBUF_LEN, GFP_ATOMIC) != 0)
+ if (ccid2_hc_tx_alloc_seq(hctx))
return -ENOMEM;
hctx->ccid2hctx_sent = 0;
-
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