Re: [PATCH 2/4] crypto: caam_rng: fix rng_unmap_ctx's DMA_UNMAP size problem

["Horia Geantă" <horia.geanta@freescale.com>]

On 2/28/2015 8:00 AM, yanjiang.jin@windriver.com wrote:
> From: Yanjiang Jin <yanjiang.jin@windriver.com>
> 
> Fix rng_unmap_ctx's DMA_UNMAP size problem for caam_rng, else system would
> report the below calltrace during kexec boot:
> 
> caam_jr ffe301000.jr: DMA-API: device driver frees DMA memory with different size [device address=0x000000007f080010] [map size=16 bytes] [unmap size=40 bytes]
> ------------[ cut here ]------------
> WARNING: at lib/dma-debug.c:887
> Modules linked in:
> CPU: 1 PID: 730 Comm: kexec Not tainted 3.10.62-ltsi-WR6.0.0.0_standard #188
> task: c0000000f7cdaa80 ti: c0000000e5340000 task.ti: c0000000e5340000
> NIP: c0000000004f5bc8 LR: c0000000004f5bc4 CTR: c0000000005f69b0
> REGS: c0000000e53433c0 TRAP: 0700   Not tainted  (3.10.62-ltsi-WR6.0.0.0_standard)
> MSR: 0000000080029000 <CE,EE,ME>  CR: 24088482  XER: 00000000
> SOFTE: 0
> 
> GPR00: c0000000004f5bc4 c0000000e5343640 c0000000012af360 000000000000009f
> GPR04: 0000000000000000 00000000000000a0 c000000000d02070 c000000015980660
> GPR08: c000000000cff360 0000000000000000 0000000000000000 c0000000012da018
> GPR12: 00000000000001e3 c000000001fff780 00000000100f0000 0000000000000001
> GPR16: 0000000000000002 0000000000000000 0000000000000000 0000000000000000
> GPR20: 0000000000000000 0000000000000000 ffffffffffffffff 0000000000000001
> GPR24: 0000000000000001 0000000000000001 0000000000000000 0000000000000001
> GPR28: c000000001556b90 c000000001565b80 c0000000e5343750 c0000000f9427480
> NIP [c0000000004f5bc8] .check_unmap+0x538/0x9c0
> LR [c0000000004f5bc4] .check_unmap+0x534/0x9c0
> Call Trace:
> [c0000000e5343640] [c0000000004f5bc4] .check_unmap+0x534/0x9c0 (unreliable)
> [c0000000e53436e0] [c0000000004f60d4] .debug_dma_unmap_page+0x84/0xb0
> [c0000000e5343810] [c00000000082f9d4] .caam_cleanup+0x1d4/0x240
> [c0000000e53438a0] [c00000000056cc88] .hwrng_unregister+0xd8/0x1c0
> [c0000000e5343930] [c00000000082fa74] .caam_rng_shutdown+0x34/0x60
> [c0000000e53439a0] [c000000000817354] .caam_remove+0x54/0x420
> [c0000000e5343a70] [c0000000005791ac] .platform_drv_shutdown+0x3c/0x60
> [c0000000e5343af0] [c000000000573728] .device_shutdown+0x128/0x240
> [c0000000e5343b90] [c0000000000880b4] .kernel_restart_prepare+0x54/0x70
> [c0000000e5343c10] [c0000000000e5cac] .kernel_kexec+0x9c/0xd0
> [c0000000e5343c90] [c000000000088404] .SyS_reboot+0x244/0x2d0
> [c0000000e5343e30] [c000000000000718] syscall_exit+0x0/0x8c
> Instruction dump:
> 7c641b78 41de0410 e8a90050 2fa50000 419e0484 e8de0028 e8ff0030 3c62ff90
> e91e0030 38638388 48546ed9 60000000 <0fe00000> 3c62ff8f 38637fc8 48546ec5
> ---[ end trace e43fd1734d6600df ]---
> 
> Signed-off-by: Yanjiang Jin <yanjiang.jin@windriver.com>

Reviewed-by: Horia Geanta <horia.geanta@freescale.com>

> ---
>  drivers/crypto/caam/caamrng.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/crypto/caam/caamrng.c b/drivers/crypto/caam/caamrng.c
> index ae31e55..314f73d 100644
> --- a/drivers/crypto/caam/caamrng.c
> +++ b/drivers/crypto/caam/caamrng.c
> @@ -90,8 +90,8 @@ static inline void rng_unmap_ctx(struct caam_rng_ctx *ctx)
>  	struct device *jrdev = ctx->jrdev;
>  
>  	if (ctx->sh_desc_dma)
> -		dma_unmap_single(jrdev, ctx->sh_desc_dma, DESC_RNG_LEN,
> -				 DMA_TO_DEVICE);
> +		dma_unmap_single(jrdev, ctx->sh_desc_dma,
> +				desc_bytes(ctx->sh_desc), DMA_TO_DEVICE);
>  	rng_unmap_buf(jrdev, &ctx->bufs[0]);
>  	rng_unmap_buf(jrdev, &ctx->bufs[1]);
>  }
>