--- /dev/null
+From 29231826f3bd65500118c473fccf31c0cf14dbc0 Mon Sep 17 00:00:00 2001
+From: Quentin Perret <qperret@google.com>
+Date: Wed, 16 Sep 2020 18:18:25 +0100
+Subject: ehci-hcd: Move include to keep CRC stable
+
+From: Quentin Perret <qperret@google.com>
+
+commit 29231826f3bd65500118c473fccf31c0cf14dbc0 upstream.
+
+The CRC calculation done by genksyms is triggered when the parser hits
+EXPORT_SYMBOL*() macros. At this point, genksyms recursively expands the
+types of the function parameters, and uses that as the input for the CRC
+calculation. In the case of forward-declared structs, the type expands
+to 'UNKNOWN'. Following this, it appears that the result of the
+expansion of each type is cached somewhere, and seems to be re-used
+when/if the same type is seen again for another exported symbol in the
+same C file.
+
+Unfortunately, this can cause CRC 'stability' issues when a struct
+definition becomes visible in the middle of a C file. For example, let's
+assume code with the following pattern:
+
+ struct foo;
+
+ int bar(struct foo *arg)
+ {
+ /* Do work ... */
+ }
+ EXPORT_SYMBOL_GPL(bar);
+
+ /* This contains struct foo's definition */
+ #include "foo.h"
+
+ int baz(struct foo *arg)
+ {
+ /* Do more work ... */
+ }
+ EXPORT_SYMBOL_GPL(baz);
+
+Here, baz's CRC will be computed using the expansion of struct foo that
+was cached after bar's CRC calculation ('UNKOWN' here). But if
+EXPORT_SYMBOL_GPL(bar) is removed from the file (because of e.g. symbol
+trimming using CONFIG_TRIM_UNUSED_KSYMS), struct foo will be expanded
+late, during baz's CRC calculation, which now has visibility over the
+full struct definition, hence resulting in a different CRC for baz.
+
+The proper fix for this certainly is in genksyms, but that will take me
+some time to get right. In the meantime, we have seen one occurrence of
+this in the ehci-hcd code which hits this problem because of the way it
+includes C files halfway through the code together with an unlucky mix
+of symbol trimming.
+
+In order to workaround this, move the include done in ehci-hub.c early
+in ehci-hcd.c, hence making sure the struct definitions are visible to
+the entire file. This improves CRC stability of the ehci-hcd exports
+even when symbol trimming is enabled.
+
+Acked-by: Alan Stern <stern@rowland.harvard.edu>
+Cc: stable <stable@vger.kernel.org>
+Signed-off-by: Quentin Perret <qperret@google.com>
+Link: https://lore.kernel.org/r/20200916171825.3228122-1-qperret@google.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/usb/host/ehci-hcd.c | 1 +
+ drivers/usb/host/ehci-hub.c | 1 -
+ 2 files changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/usb/host/ehci-hcd.c
++++ b/drivers/usb/host/ehci-hcd.c
+@@ -35,6 +35,7 @@
+ #include <linux/interrupt.h>
+ #include <linux/usb.h>
+ #include <linux/usb/hcd.h>
++#include <linux/usb/otg.h>
+ #include <linux/moduleparam.h>
+ #include <linux/dma-mapping.h>
+ #include <linux/debugfs.h>
+--- a/drivers/usb/host/ehci-hub.c
++++ b/drivers/usb/host/ehci-hub.c
+@@ -27,7 +27,6 @@
+ */
+
+ /*-------------------------------------------------------------------------*/
+-#include <linux/usb/otg.h>
+
+ #define PORT_WAKE_BITS (PORT_WKOC_E|PORT_WKDISC_E|PORT_WKCONN_E)
+
--- /dev/null
+From 437ef802e0adc9f162a95213a3488e8646e5fc03 Mon Sep 17 00:00:00 2001
+From: Alexey Kardashevskiy <aik@ozlabs.ru>
+Date: Tue, 8 Sep 2020 11:51:06 +1000
+Subject: powerpc/dma: Fix dma_map_ops::get_required_mask
+
+From: Alexey Kardashevskiy <aik@ozlabs.ru>
+
+commit 437ef802e0adc9f162a95213a3488e8646e5fc03 upstream.
+
+There are 2 problems with it:
+ 1. "<" vs expected "<<"
+ 2. the shift number is an IOMMU page number mask, not an address
+ mask as the IOMMU page shift is missing.
+
+This did not hit us before f1565c24b596 ("powerpc: use the generic
+dma_ops_bypass mode") because we had additional code to handle bypass
+mask so this chunk (almost?) never executed.However there were
+reports that aacraid does not work with "iommu=nobypass".
+
+After f1565c24b596, aacraid (and probably others which call
+dma_get_required_mask() before setting the mask) was unable to enable
+64bit DMA and fall back to using IOMMU which was known not to work,
+one of the problems is double free of an IOMMU page.
+
+This fixes DMA for aacraid, both with and without "iommu=nobypass" in
+the kernel command line. Verified with "stress-ng -d 4".
+
+Fixes: 6a5c7be5e484 ("powerpc: Override dma_get_required_mask by platform hook and ops")
+Cc: stable@vger.kernel.org # v3.2+
+Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
+Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
+Link: https://lore.kernel.org/r/20200908015106.79661-1-aik@ozlabs.ru
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/powerpc/kernel/dma-iommu.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+--- a/arch/powerpc/kernel/dma-iommu.c
++++ b/arch/powerpc/kernel/dma-iommu.c
+@@ -99,7 +99,8 @@ static u64 dma_iommu_get_required_mask(s
+ if (!tbl)
+ return 0;
+
+- mask = 1ULL < (fls_long(tbl->it_offset + tbl->it_size) - 1);
++ mask = 1ULL << (fls_long(tbl->it_offset + tbl->it_size) +
++ tbl->it_page_shift - 1);
+ mask += mask - 1;
+
+ return mask;
projects / thirdparty / kernel / stable-queue.git / commitdiff
