xen/xenbus: avoid large structs and arrays on the stack

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xenbus_map_ring_valloc() and its sub-functions are putting quite large
structs and arrays on the stack. This is problematic at runtime, but
might also result in build failures (e.g. with clang due to the option
-Werror,-Wframe-larger-than=... used).

Fix that by moving most of the data from the stack into a dynamically
allocated struct. Performance is no issue here, as
xenbus_map_ring_valloc() is used only when adding a new PV device to
a backend driver.

While at it move some duplicated code from pv/hvm specific mapping
functions to the single caller.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20200701121638.19840-2-jgross@suse.com
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

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Juergen Gross 2020-07-01 14:16:37 +02:00 • committed by Boris Ostrovsky

parent caef73cf20

commit 3848e4e0a3

1 changed files with 83 additions and 78 deletions

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drivers/xen/xenbus/xenbus_client.c

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