arm64:dts:Add new board Hinlink HT2 and driver:wireless:add AIC8800 #128
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amazingfate
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Dec 6, 2023
hoochiwetech
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hoochiwetech
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Joshua-Riek
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copy_fd_bitmaps(new, old, count) is expected to copy the first count/BITS_PER_LONG bits from old->full_fds_bits[] and fill the rest with zeroes. What it does is copying enough words (BITS_TO_LONGS(count/BITS_PER_LONG)), then memsets the rest. That works fine, *if* all bits past the cutoff point are clear. Otherwise we are risking garbage from the last word we'd copied. For most of the callers that is true - expand_fdtable() has count equal to old->max_fds, so there's no open descriptors past count, let alone fully occupied words in ->open_fds[], which is what bits in ->full_fds_bits[] correspond to. The other caller (dup_fd()) passes sane_fdtable_size(old_fdt, max_fds), which is the smallest multiple of BITS_PER_LONG that covers all opened descriptors below max_fds. In the common case (copying on fork()) max_fds is ~0U, so all opened descriptors will be below it and we are fine, by the same reasons why the call in expand_fdtable() is safe. Unfortunately, there is a case where max_fds is less than that and where we might, indeed, end up with junk in ->full_fds_bits[] - close_range(from, to, CLOSE_RANGE_UNSHARE) with * descriptor table being currently shared * 'to' being above the current capacity of descriptor table * 'from' being just under some chunk of opened descriptors. In that case we end up with observably wrong behaviour - e.g. spawn a child with CLONE_FILES, get all descriptors in range 0..127 open, then close_range(64, ~0U, CLOSE_RANGE_UNSHARE) and watch dup(0) ending up with descriptor armbian#128, despite armbian#64 being observably not open. The minimally invasive fix would be to deal with that in dup_fd(). If this proves to add measurable overhead, we can go that way, but let's try to fix copy_fd_bitmaps() first. * new helper: bitmap_copy_and_expand(to, from, bits_to_copy, size). * make copy_fd_bitmaps() take the bitmap size in words, rather than bits; it's 'count' argument is always a multiple of BITS_PER_LONG, so we are not losing any information, and that way we can use the same helper for all three bitmaps - compiler will see that count is a multiple of BITS_PER_LONG for the large ones, so it'll generate plain memcpy()+memset(). Reproducer added to tools/testing/selftests/core/close_range_test.c Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Hinlink HT2 is based on Hinlink h28k.
deletes 1 gigabit port and adds 1 HDMI output
1 USB3.0 host and 1 wifi module
AIC8800 is a WiFi6/BT5.3 combo low-power, high-performance and high-integrated dual band
wireless communication module which is designed for meeting the customers’ needs of
small size and low cost. This module supports both WLAN and BT functions. Its WLAN/BT
function supports the USB2.0/SDIO3.0 interface, and its BT function supports the UART
interface, and the module meets the requirements of standard protocol IEEE
802.11 a/b/g/n/ac/ax. Such units as power management, power amplifier and low�noise amplifier are integrated in the main chip of the module. Its WLAN PHY rate is up
to 600.4Mbps@TX. The module can be applied in smart sound boxes, set-top boxes,
game machines, printers, IP cameras, tachographs, and other smart equipment. This
documentation describes the engineering requirements specification.