| Message ID | 20180523144615.GA24563@jordon-HP-15-Notebook-PC (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Souptick,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on drm/drm-next]
[also build test WARNING on v4.17-rc6]
[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/Souptick-Joarder/gpu-drm-gma500-Change-return-type-to-vm_fault_t/20180526-084629
base: git://people.freedesktop.org/~airlied/linux.git drm-next
config: x86_64-randconfig-x013-201820 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings
All warnings (new ones prefixed by >>):
drivers/gpu//drm/gma500/framebuffer.c: In function 'psbfb_vm_fault':
>> drivers/gpu//drm/gma500/framebuffer.c:143:9: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized]
return ret;
^~~
vim +/ret +143 drivers/gpu//drm/gma500/framebuffer.c
113
114 static vm_fault_t psbfb_vm_fault(struct vm_fault *vmf)
115 {
116 struct vm_area_struct *vma = vmf->vma;
117 struct psb_framebuffer *psbfb = vma->vm_private_data;
118 struct drm_device *dev = psbfb->base.dev;
119 struct drm_psb_private *dev_priv = dev->dev_private;
120 int page_num;
121 int i;
122 unsigned long address;
123 vm_fault_t ret;
124 unsigned long pfn;
125 unsigned long phys_addr = (unsigned long)dev_priv->stolen_base +
126 psbfb->gtt->offset;
127
128 page_num = vma_pages(vma);
129 address = vmf->address - (vmf->pgoff << PAGE_SHIFT);
130
131 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
132
133 for (i = 0; i < page_num; i++) {
134 pfn = (phys_addr >> PAGE_SHIFT);
135
136 ret = vmf_insert_mixed(vma, address,
137 __pfn_to_pfn_t(pfn, PFN_DEV));
138 if (unlikely(ret & VM_FAULT_ERROR))
139 break;
140 address += PAGE_SIZE;
141 phys_addr += PAGE_SIZE;
142 }
> 143 return ret;
144 }
145
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
On Sat, May 26, 2018 at 8:11 AM, kbuild test robot <lkp@intel.com> wrote: > Hi Souptick, > > Thank you for the patch! Perhaps something to improve: > > [auto build test WARNING on drm/drm-next] > [also build test WARNING on v4.17-rc6] > [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/Souptick-Joarder/gpu-drm-gma500-Change-return-type-to-vm_fault_t/20180526-084629 > base: git://people.freedesktop.org/~airlied/linux.git drm-next > config: x86_64-randconfig-x013-201820 (attached as .config) > compiler: gcc-7 (Debian 7.3.0-16) 7.3.0 > reproduce: > # save the attached .config to linux build tree > make ARCH=x86_64 > > Note: it may well be a FALSE warning. FWIW you are at least aware of it now. > http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings > > All warnings (new ones prefixed by >>): > > drivers/gpu//drm/gma500/framebuffer.c: In function 'psbfb_vm_fault': >>> drivers/gpu//drm/gma500/framebuffer.c:143:9: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized] > return ret; > ^~~ Sorrry about it. Will fix and send v3.
diff --git a/drivers/gpu/drm/gma500/framebuffer.c b/drivers/gpu/drm/gma500/framebuffer.c index cb0a2ae..7635ce8 100644 --- a/drivers/gpu/drm/gma500/framebuffer.c +++ b/drivers/gpu/drm/gma500/framebuffer.c @@ -111,7 +111,7 @@ static int psbfb_pan(struct fb_var_screeninfo *var, struct fb_info *info) return 0; } -static int psbfb_vm_fault(struct vm_fault *vmf) +static vm_fault_t psbfb_vm_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; struct psb_framebuffer *psbfb = vma->vm_private_data; @@ -120,7 +120,7 @@ static int psbfb_vm_fault(struct vm_fault *vmf) int page_num; int i; unsigned long address; - int ret; + vm_fault_t ret; unsigned long pfn; unsigned long phys_addr = (unsigned long)dev_priv->stolen_base + psbfb->gtt->offset; @@ -133,18 +133,14 @@ static int psbfb_vm_fault(struct vm_fault *vmf) for (i = 0; i < page_num; i++) { pfn = (phys_addr >> PAGE_SHIFT); - ret = vm_insert_mixed(vma, address, + ret = vmf_insert_mixed(vma, address, __pfn_to_pfn_t(pfn, PFN_DEV)); - if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0))) + if (unlikely(ret & VM_FAULT_ERROR)) break; - else if (unlikely(ret != 0)) { - ret = (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS; - return ret; - } address += PAGE_SIZE; phys_addr += PAGE_SIZE; } - return VM_FAULT_NOPAGE; + return ret; } static void psbfb_vm_open(struct vm_area_struct *vma) diff --git a/drivers/gpu/drm/gma500/gem.c b/drivers/gpu/drm/gma500/gem.c index 1312397..e7be5c9 100644 --- a/drivers/gpu/drm/gma500/gem.c +++ b/drivers/gpu/drm/gma500/gem.c @@ -134,12 +134,13 @@ int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev, * vma->vm_private_data points to the GEM object that is backing this * mapping. */ -int psb_gem_fault(struct vm_fault *vmf) +vm_fault_t psb_gem_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; struct drm_gem_object *obj; struct gtt_range *r; - int ret; + int err; + vm_fault_t ret; unsigned long pfn; pgoff_t page_offset; struct drm_device *dev; @@ -158,9 +159,10 @@ int psb_gem_fault(struct vm_fault *vmf) /* For now the mmap pins the object and it stays pinned. As things stand that will do us no harm */ if (r->mmapping == 0) { - ret = psb_gtt_pin(r); - if (ret < 0) { - dev_err(dev->dev, "gma500: pin failed: %d\n", ret); + err = psb_gtt_pin(r); + if (err < 0) { + dev_err(dev->dev, "gma500: pin failed: %d\n", err); + ret = vmf_error(err); goto fail; } r->mmapping = 1; @@ -175,18 +177,9 @@ int psb_gem_fault(struct vm_fault *vmf) pfn = (dev_priv->stolen_base + r->offset) >> PAGE_SHIFT; else pfn = page_to_pfn(r->pages[page_offset]); - ret = vm_insert_pfn(vma, vmf->address, pfn); - + ret = vmf_insert_pfn(vma, vmf->address, pfn); fail: mutex_unlock(&dev_priv->mmap_mutex); - switch (ret) { - case 0: - case -ERESTARTSYS: - case -EINTR: - return VM_FAULT_NOPAGE; - case -ENOMEM: - return VM_FAULT_OOM; - default: - return VM_FAULT_SIGBUS; - } + + return ret; } diff --git a/drivers/gpu/drm/gma500/psb_drv.h b/drivers/gpu/drm/gma500/psb_drv.h index e8300f5..93d2f40 100644 --- a/drivers/gpu/drm/gma500/psb_drv.h +++ b/drivers/gpu/drm/gma500/psb_drv.h @@ -21,6 +21,7 @@ #define _PSB_DRV_H_ #include <linux/kref.h> +#include <linux/mm_types.h> #include <drm/drmP.h> #include <drm/drm_global.h> @@ -749,7 +750,7 @@ extern int psb_gem_get_aperture(struct drm_device *dev, void *data, struct drm_file *file); extern int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev, struct drm_mode_create_dumb *args); -extern int psb_gem_fault(struct vm_fault *vmf); +extern vm_fault_t psb_gem_fault(struct vm_fault *vmf); /* psb_device.c */ extern const struct psb_ops psb_chip_ops;
Use new return type vm_fault_t for fault handler. For now, this is just documenting that the function returns a VM_FAULT value rather than an errno. Once all instances are converted, vm_fault_t will become a distinct type. Ref-> commit 1c8f422059ae ("mm: change return type to vm_fault_t") Previously vm_insert_{pfn,mixed} returns err which driver mapped into VM_FAULT_* type. The new function vmf_insert_{pfn,mixed} will replace this inefficiency by returning VM_FAULT_* type. vmf_error() is the newly introduce inline function in 4.17-rc6. Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> --- v2: updated the change log drivers/gpu/drm/gma500/framebuffer.c | 14 +++++--------- drivers/gpu/drm/gma500/gem.c | 27 ++++++++++----------------- drivers/gpu/drm/gma500/psb_drv.h | 3 ++- 3 files changed, 17 insertions(+), 27 deletions(-)