From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerrit Renker Date: Sun, 08 Jul 2007 11:40:28 +0000 Subject: [PATCH 1/8][PATCH v2]: Allocation in atomic context and simplify interface Message-Id: <200707081240.28357@strip-the-willow> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: dccp@vger.kernel.org [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] [] show_trace_log_lvl+0x1a/0x30 [ 4039.051687] [] show_trace+0x12/0x14 [ 4039.051691] [] dump_stack+0x16/0x18 [ 4039.051695] [] __might_sleep+0xaf/0xbe [ 4039.051700] [] __kmalloc+0xb1/0xd0 [ 4039.051706] [] ccid2_hc_tx_alloc_seq+0x35/0xc3 [dccp_ccid2] [ 4039.051717] [] ccid2_hc_tx_packet_sent+0x27f/0x2d9 [dccp_ccid2] [ 4039.051723] [] dccp_write_xmit+0x1eb/0x338 [dccp] [ 4039.051741] [] dccp_sendmsg+0x113/0x18f [dccp] [ 4039.051750] [] inet_sendmsg+0x2e/0x4c [ 4039.051758] [] sock_aio_write+0xd5/0x107 [ 4039.051766] [] do_sync_write+0xcd/0x11c [ 4039.051772] [] vfs_write+0x118/0x11f [ 4039.051840] [] sys_write+0x3d/0x64 [ 4039.051845] [] 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 --- 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;