> From: Jerin Jacob [mailto:[email protected]] > Sent: Tuesday, 11 November 2025 07.25 > > On Mon, Nov 10, 2025 at 9:01 PM Marat Khalili > <[email protected]> wrote: > > > > Left shifts of integer literals and bool values overwriting the sign > bit > > were used multiple times in bpf_jit_arm64.c. E.g.: > > > > insn = (!!is64) << 31; > > > > where is64 has type bool (double bang is a no-op here). The operand > of > > left shift was promoted to type int, which when 32-bit wide cannot > > represent the result. Similarly literal integers have int type by > > default. Sanitizer produced the following diagnostic during runtime > > (for various lines): > > > > lib/bpf/bpf_jit_arm64.c:241:18: runtime error: left shift of 1 by > 31 > > places cannot be represented in type 'int' > > Wonder why none of the tests in app/test/test_bpf.c able to catch > this? The generated ARM opcode looks OK (otherwise tests wont pass). > Could you check what is missing in the app/test/test_bpf.c? > > Also SHIFT_VAR32 needs goto common code. > > > > > > To fix the issue use RTE_BIT32 and similar macros instead. > > > > Signed-off-by: Marat Khalili <[email protected]> > > --- > > lib/bpf/bpf_jit_arm64.c | 188 +++++++++++++++++++++++--------------- > -- > > 1 file changed, 107 insertions(+), 81 deletions(-) > > > > diff --git a/lib/bpf/bpf_jit_arm64.c b/lib/bpf/bpf_jit_arm64.c > > index 96b8cd2e03..5f43db0170 100644 > > --- a/lib/bpf/bpf_jit_arm64.c > > +++ b/lib/bpf/bpf_jit_arm64.c > > @@ -28,7 +28,33 @@ > > #define A64_ZR 31 > > > > #define check_imm(n, val) (((val) >= 0) ? !!((val) >> (n)) : > !!((~val) >> (n))) > > -#define mask_imm(n, val) ((val) & ((1 << (n)) - 1)) > > +#define mask_imm(n, val) ((val) & (RTE_BIT32(n) - 1)) > > + > > +/** > > + * Get the uint32_t shifted value. > > + * > > + * Works similarly to RTE_SHIFT_VAL32 but accepts non-literal > arguments. > > + * Performs identically to RTE_SHIFT_VAL32 with literal arguments. > > + * > > + * @param val > > + * The value to be shifted, can be non-literal. > > + * @param nr > > + * The shift number in range of 0 to (32 - width of val). > > + */ > > +#define SHIFT_VAR32(val, nr) ((uint32_t)(val) << (nr)) > > + > > +/** > > + * Get the uint64_t shifted value. > > + * > > + * Works similarly to RTE_SHIFT_VAL64 but accepts non-literal > arguments. > > + * Performs identically to RTE_SHIFT_VAL64 with literal arguments. > > + * > > + * @param val > > + * The value to be shifted, can be non-literal. > > + * @param nr > > + * The shift number in range of 0 to (64 - width of val). > > + */ > > +#define SHIFT_VAR64(val, nr) ((uint64_t)(val) << (nr))
Better replace the RTE_SHIFT_VAL32/VAL64 macros with these, to support both literal and non-literal arguments.
