1 files changed, 87 insertions, 0 deletions
diff --git a/sim/testsuite/bpf/ldabs.s b/sim/testsuite/bpf/ldabs.s
new file mode 100644
index 0000000..ae777f1
--- /dev/null
+++ b/sim/testsuite/bpf/ldabs.s
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+# mach: bpf
+# sim: --skb-data-offset=0x20
+# output: pass\nexit 0 (0x0)\n
+;;; ldabs.s
+;;; Tests for non-generic BPF load instructions in simulator.
+;;; These instructions (ld{abs,ind}{b,h,w,dw}) are used to access
+;;; kernel socket data from BPF programs for high performance filters.
+;;;
+;;; Register r6 is an implicit input holding a pointer to a struct sk_buff.
+;;; Register r0 is an implicit output, holding the fetched data.
+;;;
+;;; e.g.
+;;; ldabsw means:
+;;; r0 = ntohl (*(u32 *) (((struct sk_buff *)r6)->data + imm32))
+;;;
+;;; ldindw means
+;;; r0 = ntohl (*(u32 *) (((struct sk_buff *)r6)->data + src_reg + imm32))
+
+    .include "testutils.inc"
+
+    .text
+    .global main
+    .type main, @function
+main:
+    ;; R6 holds a pointer to a struct sk_buff, which we pretend
+    ;; exists at 0x1000
+    mov         %r6, 0x1000
+
+    ;; We configure skb-data-offset=0x20
+    ;; This specifies offsetof(struct sk_buff, data), where the field 'data'
+    ;; is a pointer a data buffer, in this case at 0x2000
+    stw         [%r6+0x20], 0x2000
+
+    ;; Write the value 0x7eadbeef into memory at 0x2004
+    ;; i.e. offset 4 within the data buffer pointed to by
+    ;; ((struct sk_buff *)r6)->data
+    stw         [%r6+0x1004], 0xdeadbeef
+
+    ;; Now load data[4] into r0 using the ldabsw instruction
+    ldabsw      0x4
+
+    ;; ...and compare to what we expect
+    fail_ne32   %r0, 0xdeadbeef
+
+    ;; Repeat for a half-word (2-bytes)
+    sth         [%r6+0x1008], 0x1234
+    ldabsh      0x8
+    fail_ne32   %r0, 0x1234
+
+    ;; Repeat for a single byte
+    stb         [%r6+0x1010], 0x5a
+    ldabsb      0x10
+    fail_ne32   %r0, 0x5a
+
+    ;; Repeat for a double-word (8-byte)
+    ;; (note: fail_ne macro uses r0, so copy to another r1 to compare)
+    lddw        %r2, 0x1234deadbeef5678
+    stxdw       [%r6+0x1018], %r2
+    ldabsdw     0x18
+    mov         %r1, %r0
+    fail_ne     %r1, 0x1234deadbeef5678
+
+    ;; Now, we do the same for the indirect loads
+    mov         %r7, 0x100
+    stw         [%r6+0x1100], 0xfeedbeef
+
+    ldindw      %r7, 0x0
+    fail_ne32   %r0, 0xfeedbeef
+
+    ;; half-word
+    sth         [%r6+0x1104], 0x6789
+    ldindh      %r7, 0x4
+    fail_ne32   %r0, 0x6789
+
+    ;; byte
+    stb         [%r6+0x1108], 0x5f
+    ldindb      %r7, 0x8
+    fail_ne32   %r0, 0x5f
+
+    ;; double-word
+    lddw        %r2, 0xcafe12345678d00d
+    stxdw       [%r6+0x1110], %r2
+    ldinddw     %r7, 0x10
+    mov         %r1, %r0
+    fail_ne     %r1, 0xcafe12345678d00d
+
+    pass