From: Christoph Hellwig <hch@lst.de>
To: Andrew Morton <akpm@linux-foundation.org>,
Jani Nikula <jani.nikula@linux.intel.com>,
Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Daniel Vetter <daniel.vetter@ffwll.ch>,
intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
Chris Wilson <chris@chris-wilson.co.uk>,
linux-mm@kvack.org
Subject: [Intel-gfx] [PATCH 4/4] i915: fix remap_io_sg to verify the pgprot
Date: Fri, 26 Mar 2021 06:55:05 +0100 [thread overview]
Message-ID: <20210326055505.1424432-5-hch@lst.de> (raw)
In-Reply-To: <20210326055505.1424432-1-hch@lst.de>
remap_io_sg claims that that the pgprot is pre-verified using an
io_mapping, but actually does not get passed an io_mapping and just
uses the pgprot in the VMA. Remove the apply_to_page_range abuse
and just loop over remap_pfn_range for each segment.
Note: this could use io_mapping_map_user by passing an iomap to
remap_io_sg if the maintainers can verify that the pgprot in the
iomap in the only caller is indeed the desired one here.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/gpu/drm/i915/i915_mm.c | 73 +++++++++++-----------------------
1 file changed, 23 insertions(+), 50 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_mm.c b/drivers/gpu/drm/i915/i915_mm.c
index 9a777b0ff59b05..4c8cd08c672d2d 100644
--- a/drivers/gpu/drm/i915/i915_mm.c
+++ b/drivers/gpu/drm/i915/i915_mm.c
@@ -28,46 +28,10 @@
#include "i915_drv.h"
-struct remap_pfn {
- struct mm_struct *mm;
- unsigned long pfn;
- pgprot_t prot;
-
- struct sgt_iter sgt;
- resource_size_t iobase;
-};
+#define EXPECTED_FLAGS (VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP)
#define use_dma(io) ((io) != -1)
-static inline unsigned long sgt_pfn(const struct remap_pfn *r)
-{
- if (use_dma(r->iobase))
- return (r->sgt.dma + r->sgt.curr + r->iobase) >> PAGE_SHIFT;
- else
- return r->sgt.pfn + (r->sgt.curr >> PAGE_SHIFT);
-}
-
-static int remap_sg(pte_t *pte, unsigned long addr, void *data)
-{
- struct remap_pfn *r = data;
-
- if (GEM_WARN_ON(!r->sgt.sgp))
- return -EINVAL;
-
- /* Special PTE are not associated with any struct page */
- set_pte_at(r->mm, addr, pte,
- pte_mkspecial(pfn_pte(sgt_pfn(r), r->prot)));
- r->pfn++; /* track insertions in case we need to unwind later */
-
- r->sgt.curr += PAGE_SIZE;
- if (r->sgt.curr >= r->sgt.max)
- r->sgt = __sgt_iter(__sg_next(r->sgt.sgp), use_dma(r->iobase));
-
- return 0;
-}
-
-#define EXPECTED_FLAGS (VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP)
-
/**
* remap_io_sg - remap an IO mapping to userspace
* @vma: user vma to map to
@@ -82,12 +46,7 @@ int remap_io_sg(struct vm_area_struct *vma,
unsigned long addr, unsigned long size,
struct scatterlist *sgl, resource_size_t iobase)
{
- struct remap_pfn r = {
- .mm = vma->vm_mm,
- .prot = vma->vm_page_prot,
- .sgt = __sgt_iter(sgl, use_dma(iobase)),
- .iobase = iobase,
- };
+ unsigned long pfn, len, remapped = 0;
int err;
/* We rely on prevalidation of the io-mapping to skip track_pfn(). */
@@ -96,11 +55,25 @@ int remap_io_sg(struct vm_area_struct *vma,
if (!use_dma(iobase))
flush_cache_range(vma, addr, size);
- err = apply_to_page_range(r.mm, addr, size, remap_sg, &r);
- if (unlikely(err)) {
- zap_vma_ptes(vma, addr, r.pfn << PAGE_SHIFT);
- return err;
- }
-
- return 0;
+ do {
+ if (use_dma(iobase)) {
+ if (!sg_dma_len(sgl))
+ break;
+ pfn = (sg_dma_address(sgl) + iobase) >> PAGE_SHIFT;
+ len = sg_dma_len(sgl);
+ } else {
+ pfn = page_to_pfn(sg_page(sgl));
+ len = sgl->length;
+ }
+
+ err = remap_pfn_range(vma, addr + remapped, pfn, len,
+ vma->vm_page_prot);
+ if (err)
+ break;
+ remapped += len;
+ } while ((sgl = __sg_next(sgl)));
+
+ if (err)
+ zap_vma_ptes(vma, addr, remapped);
+ return err;
}
--
2.30.1
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next prev parent reply other threads:[~2021-03-26 5:55 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-26 5:55 [Intel-gfx] add remap_pfn_range_notrack instead of reinventing it in i915 v2 Christoph Hellwig
2021-03-26 5:55 ` [Intel-gfx] [PATCH 1/4] mm: add remap_pfn_range_notrack Christoph Hellwig
2021-03-26 5:55 ` [Intel-gfx] [PATCH 2/4] mm: add a io_mapping_map_user helper Christoph Hellwig
2021-10-20 15:40 ` Lucas De Marchi
2021-10-20 19:37 ` Peter Zijlstra
2021-10-21 6:18 ` Christoph Hellwig
2021-03-26 5:55 ` [Intel-gfx] [PATCH 3/4] i915: use io_mapping_map_user Christoph Hellwig
2021-03-26 5:55 ` Christoph Hellwig [this message]
2021-05-08 19:33 ` [Intel-gfx] [PATCH 4/4] i915: fix remap_io_sg to verify the pgprot youling257
2021-05-10 8:58 ` Christoph Hellwig
2021-05-16 16:06 ` Serge Belyshev
2021-05-17 12:37 ` Christoph Hellwig
2021-05-17 13:09 ` Serge Belyshev
2021-05-17 13:11 ` Christoph Hellwig
2021-05-17 17:06 ` Matthew Auld
2021-05-18 13:21 ` Christoph Hellwig
2021-05-18 15:00 ` Matthew Auld
2021-05-19 5:46 ` Thomas Hellström (Intel)
2021-05-17 21:46 ` Thomas Hellström
2021-05-18 6:46 ` Thomas Hellström
2021-05-18 13:24 ` Christoph Hellwig
2021-05-18 13:33 ` Thomas Hellström
2021-05-18 13:23 ` Christoph Hellwig
2021-05-19 5:51 ` Thomas Hellström
2021-03-26 7:28 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for series starting with [1/4] mm: add remap_pfn_range_notrack Patchwork
2021-03-26 7:31 ` [Intel-gfx] ✗ Fi.CI.SPARSE: " Patchwork
2021-03-26 7:34 ` [Intel-gfx] ✗ Fi.CI.DOCS: " Patchwork
2021-03-26 7:59 ` [Intel-gfx] ✗ Fi.CI.BAT: failure " Patchwork
2021-04-08 10:36 ` [Intel-gfx] add remap_pfn_range_notrack instead of reinventing it in i915 v2 Daniel Vetter
2021-04-08 11:28 ` Christoph Hellwig
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