From 33a154a96e71a34a1bcca9f40da343dbbf7b38b4 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 1 Oct 2026 14:52:55 +0000 Subject: selftests/bpf: Test packet range of pointers sharing an id Add tests where two packet pointers share an id and tightening one pointer's umax from its var_off would put it less than their constant distance from the other's umax: with an index & 0x38 capped at 50, the base pointer keeps umax 50, so the pointer 8 bytes further on must keep umax 58, even though its known bits allow at most 56. These refused a valid program or accepted an out-of-bounds access before the fix: - check the advanced copy, load through the base: valid, was refused; - check the base, load the byte at base + 1 through a copy advanced by 8: was accepted; - check base + 4, load 4 bytes at base + 2 through base + 8: reads two bytes past the checked range, was accepted; - the same as the second with data_meta pointers checked against data: was accepted. These pass with and without the fix and cover nearby paths: - subtract an unknown scalar from a checked pointer and load below it (the range is kept across a new id); - reach a load through two paths whose checks cover 8 and 7 bytes after the loaded pointer; the second path must not be pruned by the first; - spill a copy of a pointer, check the pointer, fill the copy and load one byte past the checked range: the load is refused, and the copy has the range of the check. Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20261001145255.855630-2-alexei.starovoitov@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi --- lib/test_fpu_impl.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 lib/test_fpu_impl.c (limited to 'lib/test_fpu_impl.c') diff --git a/lib/test_fpu_impl.c b/lib/test_fpu_impl.c new file mode 100644 index 000000000..777894dbb --- /dev/null +++ b/lib/test_fpu_impl.c @@ -0,0 +1,37 @@ +// SPDX-License-Identifier: GPL-2.0+ + +#include + +#include "test_fpu.h" + +int test_fpu(void) +{ + /* + * This sequence of operations tests that rounding mode is + * to nearest and that denormal numbers are supported. + * Volatile variables are used to avoid compiler optimizing + * the calculations away. + */ + volatile double a, b, c, d, e, f, g; + + a = 4.0; + b = 1e-15; + c = 1e-310; + + /* Sets precision flag */ + d = a + b; + + /* Result depends on rounding mode */ + e = a + b / 2; + + /* Denormal and very large values */ + f = b / c; + + /* Depends on denormal support */ + g = a + c * f; + + if (d > a && e > a && g > a) + return 0; + else + return -EINVAL; +} -- cgit v1.3.1