Patchwork powerpc/iseries: Fix oops reading from /proc/iSeries/mf/*/cmdline

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Submitter Benjamin Herrenschmidt
Date Sept. 11, 2009, 5:37 a.m.
Message ID <1252647472.8566.66.camel@pasglop>
Download mbox | patch
Permalink /patch/33418/
State Accepted
Delegated to: Benjamin Herrenschmidt
Headers show

Comments

Benjamin Herrenschmidt - Sept. 11, 2009, 5:37 a.m.
That code uses dma_mapping_error() with a NULL device, which is
a bad idea :-) The proper fix might be to start using some kind
of pseudo device for all these low level mappings with the
hypervisor but that will be for another day. Since it directly
calls into the low level iommu code, I see no problem in having
it directly test against DMA_ERROR_CODE instead of using the
accessors with a NULL argument for now.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/platforms/iseries/mf.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

Patch

diff --git a/arch/powerpc/platforms/iseries/mf.c b/arch/powerpc/platforms/iseries/mf.c
index fef4d51..0d9343d 100644
--- a/arch/powerpc/platforms/iseries/mf.c
+++ b/arch/powerpc/platforms/iseries/mf.c
@@ -872,7 +872,7 @@  static int proc_mf_dump_cmdline(char *page, char **start, off_t off,
 		count = 256 - off;
 
 	dma_addr = iseries_hv_map(page, off + count, DMA_FROM_DEVICE);
-	if (dma_mapping_error(NULL, dma_addr))
+	if (dma_addr == DMA_ERROR_CODE)
 		return -ENOMEM;
 	memset(page, 0, off + count);
 	memset(&vsp_cmd, 0, sizeof(vsp_cmd));