1e9d90dbed
We found that callers of dma_get_seg_boundary mostly do an ALIGN with page mask and then do a page shift to get number of pages: ALIGN(boundary + 1, 1 << shift) >> shift However, the boundary might be as large as ULONG_MAX, which means that a device has no specific boundary limit. So either "+ 1" or passing it to ALIGN() would potentially overflow. According to kernel defines: #define ALIGN_MASK(x, mask) (((x) + (mask)) & ~(mask)) #define ALIGN(x, a) ALIGN_MASK(x, (typeof(x))(a) - 1) We can simplify the logic here into a helper function doing: ALIGN(boundary + 1, 1 << shift) >> shift = ALIGN_MASK(b + 1, (1 << s) - 1) >> s = {[b + 1 + (1 << s) - 1] & ~[(1 << s) - 1]} >> s = [b + 1 + (1 << s) - 1] >> s = [b + (1 << s)] >> s = (b >> s) + 1 This patch introduces and applies dma_get_seg_boundary_nr_pages() as an overflow-free helper for the dma_get_seg_boundary() callers to get numbers of pages. It also takes care of the NULL dev case for non-DMA API callers. Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com> Acked-by: Niklas Schnelle <schnelle@linux.ibm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Signed-off-by: Christoph Hellwig <hch@lst.de> |
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.. | ||
Kconfig | ||
Makefile | ||
README.dino | ||
asp.c | ||
ccio-dma.c | ||
dino.c | ||
eisa.c | ||
eisa_eeprom.c | ||
eisa_enumerator.c | ||
gsc.c | ||
gsc.h | ||
hppb.c | ||
iommu-helpers.h | ||
iommu.h | ||
iosapic.c | ||
iosapic_private.h | ||
lasi.c | ||
lba_pci.c | ||
led.c | ||
pdc_stable.c | ||
power.c | ||
sba_iommu.c | ||
superio.c | ||
wax.c |
README.dino
/* ** HP VISUALIZE Workstation PCI Bus Defect ** ** "HP has discovered a potential system defect that can affect ** the behavior of five models of HP VISUALIZE workstations when ** equipped with third-party or customer-installed PCI I/O expansion ** cards. The defect is limited to the HP C180, C160, C160L, B160L, ** and B132L VISUALIZE workstations, and will only be encountered ** when data is transmitted through PCI I/O expansion cards on the ** PCI bus. HP-supplied graphics cards that utilize the PCI bus are ** not affected." ** ** http://h20000.www2.hp.com/bizsupport/TechSupport/Home.jsp?locale=en_US&prodTypeId=12454&prodSeriesId=44443 ** ** Product First Good Serial Number ** C200/C240 (US) US67350000 **B132L+/B180 (US) US67390000 ** C200 (Europe) 3713G01000 ** B180L (Europe) 3720G01000 ** ** Note that many boards were fixed/replaced under a free replacement ** program. Assume a machine is only "suspect" until proven otherwise. ** ** "The pci_check program will also be available as application ** patch PHSS_12295" */