user/sven/linux.git/kernel/bpf/tnum.c, branch v4.14.186Linux Kernel
https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.14.1862017-08-09T00:51:34Zbpf/verifier: track signed and unsigned min/max values2017-08-09T00:51:34ZEdward Creeecree@solarflare.com2017-08-07T14:26:36Zurn:sha1:b03c9f9fdc37dab81ea04d5dacdc5995d4c224c2
Allows us to, sometimes, combine information from a signed check of one
bound and an unsigned check of the other.
We now track the full range of possible values, rather than restricting
ourselves to [0, 1<<30) and considering anything beyond that as
unknown. While this is probably not necessary, it makes the code more
straightforward and symmetrical between signed and unsigned bounds.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bpf/verifier: rework value tracking2017-08-09T00:51:34ZEdward Creeecree@solarflare.com2017-08-07T14:26:19Zurn:sha1:f1174f77b50c94eecaa658fdc56fa69b421de4b8
Unifies adjusted and unadjusted register value types (e.g. FRAME_POINTER is
now just a PTR_TO_STACK with zero offset).
Tracks value alignment by means of tracking known & unknown bits. This
also replaces the 'reg->imm' (leading zero bits) calculations for (what
were) UNKNOWN_VALUEs.
If pointer leaks are allowed, and adjust_ptr_min_max_vals returns -EACCES,
treat the pointer as an unknown scalar and try again, because we might be
able to conclude something about the result (e.g. pointer & 0x40 is either
0 or 0x40).
Verifier hooks in the netronome/nfp driver were changed to match the new
data structures.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>