From ec9c96ef3cc0124cb94375b17faaa8cff5dfdf97 Mon Sep 17 00:00:00 2001 From: Kyle McMartin Date: Wed, 19 Aug 2009 21:17:08 -0400 Subject: dma-debug: Fix check_unmap null pointer dereference While it's debatable whether or not a NULL device argument to the DMA API functions is valid... since it certainly isn't valid on devices with an IOMMU... dma-debug really shouldn't be dereferencing null pointers either. Guard against that in err_printk and the driver_filter functions. A Fedora rawhide user was seeing this in one of the dvb drivers resulting in an oops on boot. [ A patch has been sent for testing to the driver, but I feel the dma debugging support should be fixed as well. (There's still a pile of legacy garbage in the kernel passing null pointers to dma_{alloc,free}_*. :( ] Signed-off-by: Kyle McMartin Cc: mchehab@infradead.org Cc: Joerg Roedel LKML-Reference: <20090820011708.GP25206@bombadil.infradead.org> Signed-off-by: Ingo Molnar --- lib/dma-debug.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) (limited to 'lib') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 65b0d99b6d0..58a9f9fc609 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -156,9 +156,13 @@ static bool driver_filter(struct device *dev) return true; /* driver filter on and initialized */ - if (current_driver && dev->driver == current_driver) + if (current_driver && dev && dev->driver == current_driver) return true; + /* driver filter on, but we can't filter on a NULL device... */ + if (!dev) + return false; + if (current_driver || !current_driver_name[0]) return false; @@ -183,17 +187,17 @@ static bool driver_filter(struct device *dev) return ret; } -#define err_printk(dev, entry, format, arg...) do { \ - error_count += 1; \ - if (driver_filter(dev) && \ - (show_all_errors || show_num_errors > 0)) { \ - WARN(1, "%s %s: " format, \ - dev_driver_string(dev), \ - dev_name(dev) , ## arg); \ - dump_entry_trace(entry); \ - } \ - if (!show_all_errors && show_num_errors > 0) \ - show_num_errors -= 1; \ +#define err_printk(dev, entry, format, arg...) do { \ + error_count += 1; \ + if (driver_filter(dev) && \ + (show_all_errors || show_num_errors > 0)) { \ + WARN(1, "%s %s: " format, \ + dev ? dev_driver_string(dev) : "NULL", \ + dev ? dev_name(dev) : "NULL", ## arg); \ + dump_entry_trace(entry); \ + } \ + if (!show_all_errors && show_num_errors > 0) \ + show_num_errors -= 1; \ } while (0); /* -- cgit v1.2.3 From f4b0373b26567cafd421d91101852ed7a34e9e94 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 21 Aug 2009 09:26:15 -0700 Subject: Make bitmask 'and' operators return a result code When 'and'ing two bitmasks (where 'andnot' is a variation on it), some cases want to know whether the result is the empty set or not. In particular, the TLB IPI sending code wants to do cpumask operations and determine if there are any CPU's left in the final set. So this just makes the bitmask (and cpumask) functions return a boolean for whether the result has any bits set. Cc: stable@kernel.org (2.6.30, needed by TLB shootdown fix) Signed-off-by: Linus Torvalds --- lib/bitmap.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'lib') diff --git a/lib/bitmap.c b/lib/bitmap.c index 35a1f7ff414..702565821c9 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -179,14 +179,16 @@ void __bitmap_shift_left(unsigned long *dst, } EXPORT_SYMBOL(__bitmap_shift_left); -void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, +int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, int bits) { int k; int nr = BITS_TO_LONGS(bits); + unsigned long result = 0; for (k = 0; k < nr; k++) - dst[k] = bitmap1[k] & bitmap2[k]; + result |= (dst[k] = bitmap1[k] & bitmap2[k]); + return result != 0; } EXPORT_SYMBOL(__bitmap_and); @@ -212,14 +214,16 @@ void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, } EXPORT_SYMBOL(__bitmap_xor); -void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, +int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, int bits) { int k; int nr = BITS_TO_LONGS(bits); + unsigned long result = 0; for (k = 0; k < nr; k++) - dst[k] = bitmap1[k] & ~bitmap2[k]; + result |= (dst[k] = bitmap1[k] & ~bitmap2[k]); + return result != 0; } EXPORT_SYMBOL(__bitmap_andnot); -- cgit v1.2.3