random: don't try to look at entropy_count outside the lock

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As a non-atomic value, it's only safe to look at entropy_count when the
pool lock is held, so we move the BUG_ON inside the lock for correctness.

Also remove the spurious comment.  It's ok for entropy_count to
temporarily exceed POOLBITS so long as it's left in a consistent state
when the lock is released.

This is a more correct, simple, and idiomatic fix for the bug in
8b76f46a2d.  I've left the reorderings introduced by that patch in place
as they're harmless, even though they don't properly deal with potential
atomicity issues.

Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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Matt Mackall 2009-01-06 14:42:55 -08:00 • committed by Linus Torvalds

parent 71183c9480

commit cda796a3d5

1 changed files with 2 additions and 3 deletions

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drivers/char/random.c

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