user/sven/linux.git/include/linux, branch v3.16.46

include/linux/kernel.h: change abs() macro so it uses consistent return type

2017-07-18T17:40:28Z

commit 8f57e4d930d48217268315898212518d4d3e0773 upstream. Rewrite abs() so that its return type does not depend on the architecture and no unexpected type conversion happen inside of it. The only conversion is from unsigned to signed type. char is left as a return type but treated as a signed type regradless of it's actual signedness. With the old version, int arguments were promoted to long and depending on architecture a long argument might result in s64 or long return type (which may or may not be the same). This came after some back and forth with Nicolas. The current macro has different return type (for the same input type) depending on architecture which might be midly iritating. An alternative version would promote to int like so: #define abs(x) __abs_choose_expr(x, long long, \ __abs_choose_expr(x, long, \ __builtin_choose_expr( \ sizeof(x) <= sizeof(int), \ ({ int __x = (x); __x<0?-__x:__x; }), \ ((void)0)))) I have no preference but imagine Linus might. :] Nicolas argument against is that promoting to int causes iconsistent behaviour: int main(void) { unsigned short a = 0, b = 1, c = a - b; unsigned short d = abs(a - b); unsigned short e = abs(c); printf("%u %u\n", d, e); // prints: 1 65535 } Then again, no sane person expects consistent behaviour from C integer arithmetic. ;) Note: __builtin_types_compatible_p(unsigned char, char) is always false, and __builtin_types_compatible_p(signed char, char) is also always false. Signed-off-by: Michal Nazarewicz Reviewed-by: Nicolas Pitre Cc: Srinivas Pandruvada Cc: Wey-Yi Guy Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings

kernel.h: make abs() work with 64-bit types

2017-07-18T17:40:28Z

commit c8299cb605b27dd5a49f7a69e48fd23e5a206298 upstream. For 64-bit arguments, the abs macro casts it to an int which leads to lost precision and may cause incorrect results. To deal with 64-bit types abs64 macro has been introduced but still there are places where abs macro is used incorrectly. To deal with the problem, expand abs macro such that it operates on s64 type when dealing with 64-bit types while still returning long when dealing with smaller types. This fixes one known bug (per John): The internal clocksteering done for fine-grained error correction uses a : logarithmic approximation, so any time adjtimex() adjusts the clock : steering, timekeeping_freqadjust() quickly approximates the correct clock : frequency over a series of ticks. : : Unfortunately, the logic in timekeeping_freqadjust(), introduced in commit : dc491596f639438 (Rework frequency adjustments to work better w/ nohz), : used the abs() function with a s64 error value to calculate the size of : the approximated adjustment to be made. : : Per include/linux/kernel.h: "abs() should not be used for 64-bit types : (s64, u64, long long) - use abs64()". : : Thus on 32-bit platforms, this resulted in the clocksteering to take a : quite dampended random walk trying to converge on the proper frequency, : which caused the adjustments to be made much slower then intended (most : easily observed when large adjustments are made). Signed-off-by: Michal Nazarewicz Reported-by: John Stultz Tested-by: John Stultz Cc: Ingo Molnar Cc: Steven Rostedt Cc: Peter Zijlstra Cc: Masami Hiramatsu Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings

KVM: kvm_io_bus_unregister_dev() should never fail

2017-07-18T17:40:22Z

commit 90db10434b163e46da413d34db8d0e77404cc645 upstream. No caller currently checks the return value of kvm_io_bus_unregister_dev(). This is evil, as all callers silently go on freeing their device. A stale reference will remain in the io_bus, getting at least used again, when the iobus gets teared down on kvm_destroy_vm() - leading to use after free errors. There is nothing the callers could do, except retrying over and over again. So let's simply remove the bus altogether, print an error and make sure no one can access this broken bus again (returning -ENOMEM on any attempt to access it). Fixes: e93f8a0f821e ("KVM: convert io_bus to SRCU") Reported-by: Dmitry Vyukov Reviewed-by: Cornelia Huck Signed-off-by: David Hildenbrand Signed-off-by: Paolo Bonzini [bwh: Backported to 3.16: - Drop changes to kvm_io_bus_get_dev() - Adjust context] Signed-off-by: Ben Hutchings

bpf: try harder on clones when writing into skb

2017-07-18T17:40:20Z

commit 3697649ff29e0f647565eed04b27a7779c646a22 upstream. When we're dealing with clones and the area is not writeable, try harder and get a copy via pskb_expand_head(). Replace also other occurences in tc actions with the new skb_try_make_writable(). Reported-by: Ashhad Sheikh Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller [bwh: Backported to 3.16: drop changes to bpf; only tc actions need fixing] Signed-off-by: Ben Hutchings

usb-core: Add LINEAR_FRAME_INTR_BINTERVAL USB quirk

2017-07-18T17:40:14Z

commit 3243367b209faed5c320a4e5f9a565ee2a2ba958 upstream. Some USB 2.0 devices erroneously report millisecond values in bInterval. The generic config code manages to catch most of them, but in some cases it's not completely enough. The case at stake here is a USB 2.0 braille device, which wants to announce 10ms and thus sets bInterval to 10, but with the USB 2.0 computation that yields to 64ms. It happens that one can type fast enough to reach this interval and get the device buffers overflown, leading to problematic latencies. The generic config code does not catch this case because the 64ms is considered a sane enough value. This change thus adds a USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL quirk to mark devices which actually report milliseconds in bInterval, and marks Vario Ultra devices as needing it. Signed-off-by: Samuel Thibault Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings

net: phy: Do not perform software reset for Generic PHY

2017-07-18T17:40:06Z

commit 0878fff1f42c18e448ab5b8b4f6a3eb32365b5b6 upstream. The Generic PHY driver is a catch-all PHY driver and it should preserve whatever prior initialization has been done by boot loader or firmware agents. For specific PHY device configuration it is expected that a specialized PHY driver would take over that role. Resetting the generic PHY was a bad idea that has lead to several complaints and downstream workarounds e.g: in OpenWrt/LEDE so restore the behavior prior to 87aa9f9c61ad ("net: phy: consolidate PHY reset in phy_init_hw()"). Reported-by: Felix Fietkau Fixes: 87aa9f9c61ad ("net: phy: consolidate PHY reset in phy_init_hw()") Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

mm: larger stack guard gap, between vmas

2017-07-02T16:13:02Z

commit 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream. Stack guard page is a useful feature to reduce a risk of stack smashing into a different mapping. We have been using a single page gap which is sufficient to prevent having stack adjacent to a different mapping. But this seems to be insufficient in the light of the stack usage in userspace. E.g. glibc uses as large as 64kB alloca() in many commonly used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX] which is 256kB or stack strings with MAX_ARG_STRLEN. This will become especially dangerous for suid binaries and the default no limit for the stack size limit because those applications can be tricked to consume a large portion of the stack and a single glibc call could jump over the guard page. These attacks are not theoretical, unfortunatelly. Make those attacks less probable by increasing the stack guard gap to 1MB (on systems with 4k pages; but make it depend on the page size because systems with larger base pages might cap stack allocations in the PAGE_SIZE units) which should cover larger alloca() and VLA stack allocations. It is obviously not a full fix because the problem is somehow inherent, but it should reduce attack space a lot. One could argue that the gap size should be configurable from userspace, but that can be done later when somebody finds that the new 1MB is wrong for some special case applications. For now, add a kernel command line option (stack_guard_gap) to specify the stack gap size (in page units). Implementation wise, first delete all the old code for stack guard page: because although we could get away with accounting one extra page in a stack vma, accounting a larger gap can break userspace - case in point, a program run with "ulimit -S -v 20000" failed when the 1MB gap was counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK and strict non-overcommit mode. Instead of keeping gap inside the stack vma, maintain the stack guard gap as a gap between vmas: using vm_start_gap() in place of vm_start (or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few places which need to respect the gap - mainly arch_get_unmapped_area(), and and the vma tree's subtree_gap support for that. Original-patch-by: Oleg Nesterov Original-patch-by: Michal Hocko Signed-off-by: Hugh Dickins Acked-by: Michal Hocko Tested-by: Helge Deller # parisc Signed-off-by: Linus Torvalds [Hugh Dickins: Backported to 3.16] Signed-off-by: Ben Hutchings

locking/static_keys: Add static_key_{en,dis}able() helpers

2017-06-05T20:17:18Z

commit e33886b38cc82a9fc3b2d655dfc7f50467594138 upstream. Add two helpers to make it easier to treat the refcount as boolean. Suggested-by: Jason Baron Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Ben Hutchings

net/mlx4: && vs & typo

2017-06-05T20:17:18Z

commit b2d0fe35471d1a71471f99147ffb5986bd60e744 upstream. Bitwise & was obviously intended here. Fixes: 745d8ae4622c ("net/mlx4: Spoofcheck and zero MAC can't coexist") Signed-off-by: Dan Carpenter Reviewed-by: Tariq Toukan Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

net/mlx4: Spoofcheck and zero MAC can't coexist

2017-06-05T20:17:14Z

commit 745d8ae4622c6808b22e33a944c7decb30074be4 upstream. Spoofcheck can't be enabled if VF MAC is zero. Vice versa, can't zero MAC if spoofcheck is on. Fixes: 8f7ba3ca12f6 ('net/mlx4: Add set VF mac address support') Signed-off-by: Eugenia Emantayev Signed-off-by: Tariq Toukan Signed-off-by: David S. Miller [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings