Commit Graph

5 Commits

Author SHA1 Message Date
Jianping Liu be16237b31 tkernel: add base tlinux kernel interfaces
Sync kernel codes to the same with 590eaf1fec ("Init Repo base on
linux 5.4.32 long term, and add base tlinux kernel interfaces."), which
is from tk4, and it is the base of tk4.

Signed-off-by: Jianping Liu <frankjpliu@tencent.com>
2024-06-11 20:09:33 +08:00
Thomas Gleixner 457c899653 treewide: Add SPDX license identifier for missed files
Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have EXPORT_.*_SYMBOL_GPL inside which was used in the
   initial scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:45 +02:00
Yonghong Song 9cbe1f5a32 bpf/verifier: improve register value range tracking with ARSH
When helpers like bpf_get_stack returns an int value
and later on used for arithmetic computation, the LSH and ARSH
operations are often required to get proper sign extension into
64-bit. For example, without this patch:
    54: R0=inv(id=0,umax_value=800)
    54: (bf) r8 = r0
    55: R0=inv(id=0,umax_value=800) R8_w=inv(id=0,umax_value=800)
    55: (67) r8 <<= 32
    56: R8_w=inv(id=0,umax_value=3435973836800,var_off=(0x0; 0x3ff00000000))
    56: (c7) r8 s>>= 32
    57: R8=inv(id=0)
With this patch:
    54: R0=inv(id=0,umax_value=800)
    54: (bf) r8 = r0
    55: R0=inv(id=0,umax_value=800) R8_w=inv(id=0,umax_value=800)
    55: (67) r8 <<= 32
    56: R8_w=inv(id=0,umax_value=3435973836800,var_off=(0x0; 0x3ff00000000))
    56: (c7) r8 s>>= 32
    57: R8=inv(id=0, umax_value=800,var_off=(0x0; 0x3ff))
With better range of "R8", later on when "R8" is added to other register,
e.g., a map pointer or scalar-value register, the better register
range can be derived and verifier failure may be avoided.

In our later example,
    ......
    usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK);
    if (usize < 0)
        return 0;
    ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0);
    ......
Without improving ARSH value range tracking, the register representing
"max_len - usize" will have smin_value equal to S64_MIN and will be
rejected by verifier.

Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-04-29 08:45:53 -07:00
Edward Cree b03c9f9fdc bpf/verifier: track signed and unsigned min/max values
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>
2017-08-08 17:51:34 -07:00
Edward Cree f1174f77b5 bpf/verifier: rework value tracking
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>
2017-08-08 17:51:34 -07:00