Re: [BUG] crypto: ccree: driver does not handle case where cryptlen = authsize =0

Corentin Labbe
2022-03-07T11:22:23Z

Le Mon, Mar 07, 2022 at 09:59:29AM +0200, Gilad Ben-Yossef a écrit :
> On Sun, Mar 6, 2022 at 11:49 PM Herbert Xu <herbert@gondor.apana.org.au> wrote:
> >
> > On Fri, Mar 04, 2022 at 02:30:06PM +0100, Corentin Labbe wrote:
> > >
> > > Hello
> > >
> > > I got:
> > > [ 17.563793] ------------[ cut here ]------------
> > > [ 17.568492] DMA-API: ccree e6601000.crypto: device driver frees DMA memory with different direction [device address=0x0000000078fe5800] [size=8 bytes] [mapped with DMA_TO_DEVICE] [unmapped with DMA_BIDIRECTIONAL]
> >
> > The direction argument during unmap must match whatever direction
> > you used during the original map call.
>
>
> Yes, of course. I changed one but forgot the other.
>
> Corentin, could you be kind and check that this solves the original
> problem and does not produce new warnings?
>
> diff --git a/drivers/crypto/ccree/cc_buffer_mgr.c
> b/drivers/crypto/ccree/cc_buffer_mgr.c
> index 11e0278c8631..31cfe014922e 100644
> --- a/drivers/crypto/ccree/cc_buffer_mgr.c
> +++ b/drivers/crypto/ccree/cc_buffer_mgr.c
> @@ -356,12 +356,14 @@ void cc_unmap_cipher_request(struct device *dev,
> void *ctx,
> req_ctx->mlli_params.mlli_dma_addr);
> }
>
> - dma_unmap_sg(dev, src, req_ctx->in_nents, DMA_BIDIRECTIONAL);
> - dev_dbg(dev, "Unmapped req->src=%pK\n", sg_virt(src));
> -
> if (src != dst) {
> - dma_unmap_sg(dev, dst, req_ctx->out_nents, DMA_BIDIRECTIONAL);
> + dma_unmap_sg(dev, src, req_ctx->in_nents, DMA_TO_DEVICE);
> + dma_unmap_sg(dev, dst, req_ctx->out_nents, DMA_FROM_DEVICE);
> dev_dbg(dev, "Unmapped req->dst=%pK\n", sg_virt(dst));
> + dev_dbg(dev, "Unmapped req->src=%pK\n", sg_virt(src));
> + } else {
> + dma_unmap_sg(dev, src, req_ctx->in_nents, DMA_BIDIRECTIONAL);
> + dev_dbg(dev, "Unmapped req->src=%pK\n", sg_virt(src));
> }
> }
>
> @@ -377,6 +379,7 @@ int cc_map_cipher_request(struct cc_drvdata
> *drvdata, void *ctx,
> u32 dummy = 0;
> int rc = 0;
> u32 mapped_nents = 0;
> + int src_direction = (src != dst ? DMA_TO_DEVICE : DMA_BIDIRECTIONAL);
>
> req_ctx->dma_buf_type = CC_DMA_BUF_DLLI;
> mlli_params->curr_pool = NULL;
> @@ -399,7 +402,7 @@ int cc_map_cipher_request(struct cc_drvdata
> *drvdata, void *ctx,
> }
>
> /* Map the src SGL */
> - rc = cc_map_sg(dev, src, nbytes, DMA_BIDIRECTIONAL, &req_ctx->in_nents,
> + rc = cc_map_sg(dev, src, nbytes, src_direction, &req_ctx->in_nents,
> LLI_MAX_NUM_OF_DATA_ENTRIES, &dummy, &mapped_nents);
> if (rc)
> goto cipher_exit;
> @@ -416,7 +419,7 @@ int cc_map_cipher_request(struct cc_drvdata
> *drvdata, void *ctx,
> }
> } else {
> /* Map the dst sg */
> - rc = cc_map_sg(dev, dst, nbytes, DMA_BIDIRECTIONAL,
> + rc = cc_map_sg(dev, dst, nbytes, DMA_FROM_DEVICE,
> &req_ctx->out_nents, LLI_MAX_NUM_OF_DATA_ENTRIES,
> &dummy, &mapped_nents);
> if (rc)
>
>

Hello

I still get the warning:
[ 433.406230] ------------[ cut here ]------------
[ 433.406326] DMA-API: ccree e6601000.crypto: cacheline tracking EEXIST, overlapping mappings aren't supported
[ 433.406386] WARNING: CPU: 7 PID: 31074 at /home/clabbe/linux-next/kernel/dma/debug.c:571 add_dma_entry+0x1d0/0x288
[ 433.406434] Modules linked in:
[ 433.406458] CPU: 7 PID: 31074 Comm: kcapi Not tainted 5.17.0-rc6-next-20220303-00130-g30042e47ee47-dirty #54
[ 433.406473] Hardware name: Renesas Salvator-X board based on r8a77950 (DT)
[ 433.406484] pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 433.406498] pc : add_dma_entry+0x1d0/0x288
[ 433.406510] lr : add_dma_entry+0x1d0/0x288
[ 433.406522] sp : ffff800015da3690
[ 433.406531] x29: ffff800015da3690 x28: 0000000000000000 x27: 0000000000000000
[ 433.406562] x26: 0000000000000000 x25: ffff80000b4c7bc0 x24: ffff80000b4c7000
[ 433.406593] x23: 0000000000000000 x22: 00000000ffffffef x21: ffff80000a9b6000
[ 433.406623] x20: ffff0004c0af5c00 x19: ffff80000b420000 x18: ffffffffffffffff
[ 433.406653] x17: 6c7265766f202c54 x16: 534958454520676e x15: 000000000000022e
[ 433.406683] x14: ffff800015da3380 x13: 00000000ffffffea x12: ffff80000b4be010
[ 433.406713] x11: 0000000000000001 x10: 0000000000000001 x9 : ffff80000b4a6028
[ 433.406743] x8 : c0000000ffffefff x7 : 0000000000017fe8 x6 : ffff80000b4a5fd0
[ 433.406773] x5 : ffff0006ff795c48 x4 : 0000000000000000 x3 : 0000000000000027
[ 433.406802] x2 : 0000000000000023 x1 : 8ca4e4fbf4b87900 x0 : 0000000000000000
[ 433.406833] Call trace:
[ 433.406841] add_dma_entry+0x1d0/0x288
[ 433.406854] debug_dma_map_sg+0x150/0x398
[ 433.406869] __dma_map_sg_attrs+0x9c/0x108
[ 433.406889] dma_map_sg_attrs+0x10/0x28
[ 433.406904] cc_map_sg+0x80/0x100
[ 433.406924] cc_map_cipher_request+0x178/0x3c8
[ 433.406939] cc_cipher_process+0x210/0xb58
[ 433.406953] cc_cipher_encrypt+0x2c/0x38
[ 433.406967] crypto_skcipher_encrypt+0x44/0x78
[ 433.406986] skcipher_recvmsg+0x36c/0x420
[ 433.407003] ____sys_recvmsg+0x90/0x280
[ 433.407024] ___sys_recvmsg+0x88/0xd0
[ 433.407038] __sys_recvmsg+0x6c/0xd0
[ 433.407049] __arm64_sys_recvmsg+0x24/0x30
[ 433.407061] invoke_syscall+0x44/0x100
[ 433.407082] el0_svc_common.constprop.3+0x90/0x120
[ 433.407096] do_el0_svc+0x24/0x88
[ 433.407110] el0_svc+0x4c/0x100
[ 433.407131] el0t_64_sync_handler+0x90/0xb8
[ 433.407145] el0t_64_sync+0x170/0x174
[ 433.407160] irq event stamp: 5624
[ 433.407168] hardirqs last enabled at (5623): [<ffff80000812f6a8>] __up_console_sem+0x60/0x98
[ 433.407191] hardirqs last disabled at (5624): [<ffff800009c9a060>] el1_dbg+0x28/0x90
[ 433.407208] softirqs last enabled at (5570): [<ffff8000097e62f8>] lock_sock_nested+0x80/0xa0
[ 433.407226] softirqs last disabled at (5568): [<ffff8000097e62d8>] lock_sock_nested+0x60/0xa0
[ 433.407241] ---[ end trace 0000000000000000 ]---
[ 433.407381] DMA-API: Mapped at:
[ 433.407396] debug_dma_map_sg+0x16c/0x398
[ 433.407416] __dma_map_sg_attrs+0x9c/0x108
[ 433.407436] dma_map_sg_attrs+0x10/0x28
[ 433.407455] cc_map_sg+0x80/0x100
[ 433.407475] cc_map_cipher_request+0x178/0x3c8

BUT I start to thing this is a bug in DMA-API debug.

My sun8i-ss driver hit the same warning:
[ 142.458351] WARNING: CPU: 1 PID: 90 at kernel/dma/debug.c:597 add_dma_entry+0x2ec/0x4cc
[ 142.458429] DMA-API: sun8i-ss 1c15000.crypto: cacheline tracking EEXIST, overlapping mappings aren't supported
[ 142.458455] Modules linked in: ccm algif_aead xts cmac
[ 142.458563] CPU: 1 PID: 90 Comm: 1c15000.crypto- Not tainted 5.17.0-rc6-next-20220307-00132-g39dad568d20a-dirty #223
[ 142.458581] Hardware name: Allwinner A83t board
[ 142.458596] unwind_backtrace from show_stack+0x10/0x14
[ 142.458627] show_stack from 0xf0abdd1c
[ 142.458646] irq event stamp: 31747
[ 142.458660] hardirqs last enabled at (31753): [<c019316c>] __up_console_sem+0x50/0x60
[ 142.458688] hardirqs last disabled at (31758): [<c0193158>] __up_console_sem+0x3c/0x60
[ 142.458710] softirqs last enabled at (31600): [<c06990c8>] sun8i_ss_handle_cipher_request+0x300/0x8b8
[ 142.458738] softirqs last disabled at (31580): [<c06990c8>] sun8i_ss_handle_cipher_request+0x300/0x8b8
[ 142.458758] ---[ end trace 0000000000000000 ]---
[ 142.458771] DMA-API: Mapped at:

Yes the mapped at is empty just after.

And the sequence of DMA operations in my driver is simple, so I cannot see how any overlap could occur.

So I booted a kernel without any other user of DMA (no net,mmc,usb,media)
And I added this debug:
diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index f8ff598596b8..56b243d24bac 100644
--- a/kernel/dma/debug.c
+++ b/kernel/dma/debug.c
@@ -548,6 +548,31 @@ static void active_cacheline_remove(struct dma_debug_entry *entry)
spin_unlock_irqrestore(&radix_lock, flags);
}

+static void minidump(void) {
+ int idx;
+
+ for (idx = 0; idx < HASH_SIZE; idx++) {
+ struct hash_bucket *bucket = &dma_entry_hash[idx];
+ struct dma_debug_entry *entry;
+ unsigned long flags;
+
+ spin_lock_irqsave(&bucket->lock, flags);
+ list_for_each_entry(entry, &bucket->list, list) {
+ if (strcmp("dwmac-sun8i", dev_driver_string(entry->dev)))
+ pr_info(
+ "%s %s %s idx %d P=%llx N=%lx D=%llx L=%llx %s %s\n",
+ dev_name(entry->dev),
+ dev_driver_string(entry->dev),
+ type2name[entry->type], idx,
+ phys_addr(entry), entry->pfn,
+ entry->dev_addr, entry->size,
+ dir2name[entry->direction],
+ maperr2str[entry->map_err_type]);
+ }
+ spin_unlock_irqrestore(&bucket->lock, flags);
+ }
+}
+
/*
* Wrapper function for adding an entry to the hash.
* This function takes care of locking itself.
@@ -562,13 +587,18 @@ static void add_dma_entry(struct dma_debug_entry *entry, unsigned long attrs)
hash_bucket_add(bucket, entry);
put_hash_bucket(bucket, flags);

+ pr_info("%s start P=%llx N=%lx D=%llx L=%llx %s attrs=%x\n", __func__, phys_addr(entry), entry->pfn, entry->dev_addr, entry->size, dir2name[entry->direction], attrs);
rc = active_cacheline_insert(entry);
if (rc == -ENOMEM) {
pr_err("cacheline tracking ENOMEM, dma-debug disabled\n");
global_disable = true;
} else if (rc == -EEXIST && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
+ pr_info("%s P=%llx N=%lx D=%llx L=%llx %s attrs=%x\n", __func__, phys_addr(entry), entry->pfn, entry->dev_addr, entry->size, dir2name[entry->direction], attrs);
err_printk(entry->dev, entry,
"cacheline tracking EEXIST, overlapping mappings aren't supported\n");
+ pr_info("==================== MINIDUMP ===================\n");
+ minidump();
+ pr_info("==================== MINIDUMP END ===================\n");
}
}

and some more trace:
diff --git a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c
index 5bb950182026..c7ba32f68e41 100644
--- a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c
+++ b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c
@@ -253,6 +271,7 @@ static int sun8i_ss_cipher(struct skcipher_request *areq)
rctx->t_src[i].addr = sg_dma_address(sg);
todo = min(len, sg_dma_len(sg));
rctx->t_src[i].len = todo / 4;
+ dev_info(ss->dev, "SRC %d/%d/%d %lx len=%d bi=%d\n", i, nr_sgd, nsgd, sg_dma_address(sg), sg_dma_len(sg), areq->src == areq->dst);
dev_dbg(ss->dev, "%s total=%u SGS(%d %u off=%d) todo=%u\n", __func__,
areq->cryptlen, i, rctx->t_src[i].len, sg->offset, todo);
len -= todo;
@@ -275,6 +294,7 @@ static int sun8i_ss_cipher(struct skcipher_request *areq)
rctx->t_dst[i].addr = sg_dma_address(sg);
todo = min(len, sg_dma_len(sg));
rctx->t_dst[i].len = todo / 4;
+ dev_info(ss->dev, "DST %d/%d/%d %lx len=%d bi=%d\n", i, nr_sgd, nsgd, sg_dma_address(sg), sg_dma_len(sg), areq->src == areq->dst);
dev_dbg(ss->dev, "%s total=%u SGD(%d %u off=%d) todo=%u\n", __func__,
areq->cryptlen, i, rctx->t_dst[i].len, sg->offset, todo);
len -= todo;
diff --git a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c
index d23258f76292..6cdee02967b0 100644
--- a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c
+++ b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c
@@ -603,6 +603,7 @@ int sun8i_ss_hash_run(struct crypto_engine *engine, void *breq)
err = -EINVAL;
goto err_dma_result;
}
+ dev_info(ss->dev, "RES: %lx\n", addr_res);
addr_xpad = dma_map_single(ss->dev, tfmctx->opad, bs, DMA_TO_DEVICE);
if (dma_mapping_error(ss->dev, addr_xpad)) {
dev_err(ss->dev, "Fail to create DMA mapping of opad\n");

The boot log is viewable at http://kernel.montjoie.ovh/230073.log (seek ba79f210 to go to the interesting place).
We can see that the address handled by add_dma_entry was never handled before and so cannot overlap anything.

I have added DMA people to confirm/refute what I said.

Regards