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| author | brucec <brucec@FreeBSD.org> | 2010-12-02 22:19:30 +0000 |
|---|---|---|
| committer | brucec <brucec@FreeBSD.org> | 2010-12-02 22:19:30 +0000 |
| commit | dc1c4b92702120dc06348d91c97ca533d7a27bc6 (patch) | |
| tree | 5956ab7635210faf252c5fa49f64ff6a8bda82de /share | |
| parent | 904cc72f190967800c699fe0d05d7044b2414147 (diff) | |
| download | FreeBSD-src-dc1c4b92702120dc06348d91c97ca533d7a27bc6.zip FreeBSD-src-dc1c4b92702120dc06348d91c97ca533d7a27bc6.tar.gz | |
Disallow passing in a count of zero bytes to the bus_space(9) functions.
Passing a count of zero on i386 and amd64 for [I386|AMD64]_BUS_SPACE_MEM
causes a crash/hang since the 'loop' instruction decrements the counter
before checking if it's zero.
PR: kern/80980
Discussed with: jhb
Diffstat (limited to 'share')
| -rw-r--r-- | share/man/man9/bus_space.9 | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/share/man/man9/bus_space.9 b/share/man/man9/bus_space.9 index 5a18dfb..8c832f2 100644 --- a/share/man/man9/bus_space.9 +++ b/share/man/man9/bus_space.9 @@ -719,6 +719,9 @@ or which return data read from bus space (i.e., functions which do not obviously return an error code) do not fail. They could only fail if given invalid arguments, and in that case their behaviour is undefined. +Functions which take a count of bytes must not pass in a count of zero; +doing so will cause a panic if the kernel was compiled with +.Cd "options INVARIANTS" . .Sh TYPES Several types are defined in .In machine/bus.h |
