[1/1] drm/prime: Use sg_dma_len() macro to get sg's length

Submitted by Vivek Gautam on Jan. 7, 2019, 9:54 a.m.

Details

Message ID 20190107095433.11368-1-vivek.gautam@codeaurora.org
State New
Series "Series without cover letter"
Headers show

Commit Message

Vivek Gautam Jan. 7, 2019, 9:54 a.m.
After mapping a sg list we should use sg_dma_address(), and
sg_dma_len() macros to access sg->address and sg->length. Fix
the same for sg->length in drm_prime_sg_to_page_addr_arrays().

Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
---

This came while debugging one dmabuf import issue that we are seeing
on sdm845 target.
The dmabuf which is prepared by video (venus in this case), is imported
by drm device.
The import call flow looks like follows:

drm_gem_prime_import()
 - drm_gem_prime_import_dev()
   - dma_buf_attach() & dma_buf_map_attachment()
     - From dma_buf_map_attachment()
       - vb2_dma_sg_dmabuf_ops_map()
         - dma_map_sg(): this updates the sg->nents.

From debugging, the sg table mapping results in sg's 'nents' to be less that
the original nents. Now drm device prepares the page information based on
this sg table, and messes up with the mappings, and we start seeing random
crashes as below from drm's memory space.

Although this change isn't helping to fix the issue currently, but
this fix seems the right thing to do.

One thing to notice is that, if we restore the sg->nents to
sg->orig_nents in vb2_dma_sg_dmabuf_ops_map(), we don't see the below
corruptions.

Any pointers on this will be highly appreciated.
Thanks.

------
[  338.070558] Unable to handle kernel paging request at virtual address 0000400000000038
[  338.078751] Mem abort info:
[  338.081671]   ESR = 0x96000004
[  338.084860]   Exception class = DABT (current EL), IL = 32 bits
[  338.090972]   SET = 0, FnV = 0
[  338.094139]   EA = 0, S1PTW = 0
[  338.097393] Data abort info:
[  338.100375]   ISV = 0, ISS = 0x00000004
[  338.104362]   CM = 0, WnR = 0
[  338.107446] [0000400000000038] address between user and kernel address ranges
[  338.114801] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[  338.120527] Modules linked in: rfcomm uinput cdc_ether venus_dec venus_enc usbnet videobuf2_dma_sg videobuf2_memops hci_uart btqca bluetooth r8152 mii ath10k_snoc venus_core ath10k_core v4l2_mem2mem videobuf2_v4l2 videobuf2_common ath mac80211 ecdh_generic qcom_q6v5_mss lzo lzo_compress qcom_q6v5_adsp qcom_common qcom_q6v5 zram bridge stp llc ipt_MASQUERADE fuse snd_seq_dummy snd_seq snd_seq_device cfg80211 joydev
[  338.158192] CPU: 4 PID: 3235 Comm: chrome Tainted: G        W         4.19.0 #2
[  338.165700] Hardware name: Google Cheza (rev1) (DT)
[  338.170720] pstate: 80400009 (Nzcv daif +PAN -UAO)
[  338.175660] pc : drm_mm_insert_node_in_range+0xfc/0x348
[  338.181035] lr : drm_mm_insert_node_in_range+0x24/0x348
[  338.186407] sp : ffffff8013033b30
[  338.189816] x29: ffffff8013033bd0 x28: ffffff8008591894
[  338.195275] x27: 0000000000000010 x26: 0000000000000000
[  338.200734] x25: 0000000000000000 x24: ffffffffffffffff
[  338.206194] x23: 0000000000000000 x22: ffffffc0f48b7e08
[  338.211656] x21: 0000000000000000 x20: 000000000000005d
[  338.217118] x19: 0000000000000000 x18: 0000000000000000
[  338.222581] x17: 0000000000000000 x16: 0000000000000000
[  338.228046] x15: 0000000000000000 x14: 0000000000000000
[  338.233511] x13: 0000000000000001 x12: ffffffc0b1da7200
[  338.238978] x11: 0000000000000010 x10: 0000000000000010
[  338.244437] x9 : 0000000000000008 x8 : 0000400000000000
[  338.249898] x7 : 0000000000000000 x6 : ffffffffffffffff
[  338.255361] x5 : 0000000000000000 x4 : 0000000000000000
[  338.260823] x3 : 0000000000000000 x2 : 000000000000005d
[  338.266285] x1 : ffffffc0b1da7100 x0 : ffffffc0b0215800
[  338.271748] Process chrome (pid: 3235, stack limit = 0x000000000900f416)
[  338.278628] Call trace:
[  338.281151]  drm_mm_insert_node_in_range+0xfc/0x348
[  338.286168]  msm_gem_map_vma+0x60/0xdc
[  338.290022]  msm_gem_get_iova+0xb4/0xf4
[  338.293967]  msm_ioctl_gem_info+0x90/0xdc
[  338.298089]  drm_ioctl_kernel+0xa8/0xe8
[  338.302043]  drm_ioctl+0x218/0x384
[  338.305547]  drm_compat_ioctl+0xd8/0xe8
[  338.309503]  __arm64_compat_sys_ioctl+0x134/0x20c
[  338.314339]  el0_svc_common+0xa0/0xf0
[  338.318108]  el0_svc_compat_handler+0x2c/0x38
[  338.322588]  el0_svc_compat+0x8/0x18
[  338.326274] Code: f94066c8 aa1f03e0 321d03e9 321c03ea (f9401d0b)
[  338.332538] ---[ end trace 5c09e60869887d87 ]---
[  338.354633] Kernel panic - not syncing: Fatal exception
[  338.360018] SMP: stopping secondary CPUs
[  338.364179] Kernel Offset: disabled
[  338.367779] CPU features: 0x0,22802a18
[  338.371643] Memory Limit: none
------

 drivers/gpu/drm/drm_prime.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch hide | download patch | download mbox

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 231e3f6d5f41..0d9b1c43523a 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -945,7 +945,7 @@  int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
 
 	index = 0;
 	for_each_sg(sgt->sgl, sg, sgt->nents, count) {
-		len = sg->length;
+		len = sg_dma_length(sg);
 		page = sg_page(sg);
 		addr = sg_dma_address(sg);
 

Comments

kbuild test robot Jan. 7, 2019, 10:42 a.m.
Hi Vivek,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on v5.0-rc1 next-20190107]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Vivek-Gautam/drm-prime-Use-sg_dma_len-macro-to-get-sg-s-length/20190107-181350
config: x86_64-randconfig-x013-201901 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All errors (new ones prefixed by >>):

   drivers/gpu/drm/drm_prime.c: In function 'drm_prime_sg_to_page_addr_arrays':
>> drivers/gpu/drm/drm_prime.c:948:9: error: implicit declaration of function 'sg_dma_length'; did you mean 'sg_dma_len'? [-Werror=implicit-function-declaration]
      len = sg_dma_length(sg);
            ^~~~~~~~~~~~~
            sg_dma_len
   cc1: some warnings being treated as errors

vim +948 drivers/gpu/drm/drm_prime.c

   926	
   927	/**
   928	 * drm_prime_sg_to_page_addr_arrays - convert an sg table into a page array
   929	 * @sgt: scatter-gather table to convert
   930	 * @pages: optional array of page pointers to store the page array in
   931	 * @addrs: optional array to store the dma bus address of each page
   932	 * @max_entries: size of both the passed-in arrays
   933	 *
   934	 * Exports an sg table into an array of pages and addresses. This is currently
   935	 * required by the TTM driver in order to do correct fault handling.
   936	 */
   937	int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
   938					     dma_addr_t *addrs, int max_entries)
   939	{
   940		unsigned count;
   941		struct scatterlist *sg;
   942		struct page *page;
   943		u32 len, index;
   944		dma_addr_t addr;
   945	
   946		index = 0;
   947		for_each_sg(sgt->sgl, sg, sgt->nents, count) {
 > 948			len = sg_dma_length(sg);
   949			page = sg_page(sg);
   950			addr = sg_dma_address(sg);
   951	
   952			while (len > 0) {
   953				if (WARN_ON(index >= max_entries))
   954					return -1;
   955				if (pages)
   956					pages[index] = page;
   957				if (addrs)
   958					addrs[index] = addr;
   959	
   960				page++;
   961				addr += PAGE_SIZE;
   962				len -= PAGE_SIZE;
   963				index++;
   964			}
   965		}
   966		return 0;
   967	}
   968	EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays);
   969	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
Vivek Gautam Jan. 7, 2019, 11:24 a.m.
On Mon, Jan 7, 2019 at 4:14 PM kbuild test robot <lkp@intel.com> wrote:
>
> Hi Vivek,
>
> Thank you for the patch! Yet something to improve:
>
> [auto build test ERROR on linus/master]
> [also build test ERROR on v5.0-rc1 next-20190107]
> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
>
> url:    https://github.com/0day-ci/linux/commits/Vivek-Gautam/drm-prime-Use-sg_dma_len-macro-to-get-sg-s-length/20190107-181350
> config: x86_64-randconfig-x013-201901 (attached as .config)
> compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
> reproduce:
>         # save the attached .config to linux build tree
>         make ARCH=x86_64
>
> All errors (new ones prefixed by >>):
>
>    drivers/gpu/drm/drm_prime.c: In function 'drm_prime_sg_to_page_addr_arrays':
> >> drivers/gpu/drm/drm_prime.c:948:9: error: implicit declaration of function 'sg_dma_length'; did you mean 'sg_dma_len'? [-Werror=implicit-function-declaration]
>       len = sg_dma_length(sg);
>             ^~~~~~~~~~~~~
>             sg_dma_len

Sorry, my fat finger :(
This should be as suggested - sg_dma_len().

Thanks
Vivek

>    cc1: some warnings being treated as errors
>
> vim +948 drivers/gpu/drm/drm_prime.c
>
>    926
>    927  /**
>    928   * drm_prime_sg_to_page_addr_arrays - convert an sg table into a page array
>    929   * @sgt: scatter-gather table to convert
>    930   * @pages: optional array of page pointers to store the page array in
>    931   * @addrs: optional array to store the dma bus address of each page
>    932   * @max_entries: size of both the passed-in arrays
>    933   *
>    934   * Exports an sg table into an array of pages and addresses. This is currently
>    935   * required by the TTM driver in order to do correct fault handling.
>    936   */
>    937  int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
>    938                                       dma_addr_t *addrs, int max_entries)
>    939  {
>    940          unsigned count;
>    941          struct scatterlist *sg;
>    942          struct page *page;
>    943          u32 len, index;
>    944          dma_addr_t addr;
>    945
>    946          index = 0;
>    947          for_each_sg(sgt->sgl, sg, sgt->nents, count) {
>  > 948                  len = sg_dma_length(sg);
>    949                  page = sg_page(sg);
>    950                  addr = sg_dma_address(sg);
>    951
>    952                  while (len > 0) {
>    953                          if (WARN_ON(index >= max_entries))
>    954                                  return -1;
>    955                          if (pages)
>    956                                  pages[index] = page;
>    957                          if (addrs)
>    958                                  addrs[index] = addr;
>    959
>    960                          page++;
>    961                          addr += PAGE_SIZE;
>    962                          len -= PAGE_SIZE;
>    963                          index++;
>    964                  }
>    965          }
>    966          return 0;
>    967  }
>    968  EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays);
>    969
>
> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
kbuild test robot Jan. 7, 2019, 11:38 a.m.
Hi Vivek,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on v5.0-rc1 next-20190107]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Vivek-Gautam/drm-prime-Use-sg_dma_len-macro-to-get-sg-s-length/20190107-181350
config: i386-randconfig-s3-201901 (attached as .config)
compiler: gcc-6 (Debian 6.4.0-9) 6.4.0 20171026
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All errors (new ones prefixed by >>):

   drivers/gpu//drm/drm_prime.c: In function 'drm_prime_sg_to_page_addr_arrays':
>> drivers/gpu//drm/drm_prime.c:948:9: error: implicit declaration of function 'sg_dma_length' [-Werror=implicit-function-declaration]
      len = sg_dma_length(sg);
            ^~~~~~~~~~~~~
   cc1: some warnings being treated as errors

vim +/sg_dma_length +948 drivers/gpu//drm/drm_prime.c

   926	
   927	/**
   928	 * drm_prime_sg_to_page_addr_arrays - convert an sg table into a page array
   929	 * @sgt: scatter-gather table to convert
   930	 * @pages: optional array of page pointers to store the page array in
   931	 * @addrs: optional array to store the dma bus address of each page
   932	 * @max_entries: size of both the passed-in arrays
   933	 *
   934	 * Exports an sg table into an array of pages and addresses. This is currently
   935	 * required by the TTM driver in order to do correct fault handling.
   936	 */
   937	int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
   938					     dma_addr_t *addrs, int max_entries)
   939	{
   940		unsigned count;
   941		struct scatterlist *sg;
   942		struct page *page;
   943		u32 len, index;
   944		dma_addr_t addr;
   945	
   946		index = 0;
   947		for_each_sg(sgt->sgl, sg, sgt->nents, count) {
 > 948			len = sg_dma_length(sg);
   949			page = sg_page(sg);
   950			addr = sg_dma_address(sg);
   951	
   952			while (len > 0) {
   953				if (WARN_ON(index >= max_entries))
   954					return -1;
   955				if (pages)
   956					pages[index] = page;
   957				if (addrs)
   958					addrs[index] = addr;
   959	
   960				page++;
   961				addr += PAGE_SIZE;
   962				len -= PAGE_SIZE;
   963				index++;
   964			}
   965		}
   966		return 0;
   967	}
   968	EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays);
   969	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation