1 files changed, 37 insertions, 0 deletions

diff --git a/meta-bigendian/recipes-devtools/strace/strace/strace-4.8-arm-be8.patch b/meta-bigendian/recipes-devtools/strace/strace/strace-4.8-arm-be8.patch
new file mode 100644
index 0000000..bda4807
--- /dev/null
+++ b/meta-bigendian/recipes-devtools/strace/strace/strace-4.8-arm-be8.patch
@@ -0,0 +1,37 @@
+strace: fix system call matching code in get_scno for be8 arm
+
+on ARM V7 operating in big endian mode strace does not work:
+
+root@genericarmv7ab:~# strace ls
+pid 1356 unknown syscall trap 0x000000ef
+
+it happens because ARM V7 when runs as big endian operates in be8 mode,
+where instruction are still in little endian form. Strace get_scno reads
+instructions and matches it to certain pattern, but in armeb case it needs
+to byteswap it before that.
+
+Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org>
+Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
+---
+ syscall.c |   10 ++++++++++
+ 1 file changed, 10 insertions(+)
+
+--- a/syscall.c
++++ b/syscall.c
+@@ -1374,6 +1374,16 @@ get_scno(struct tcb *tcp)
+        scno = ptrace(PTRACE_PEEKTEXT, tcp->pid, (void *)(arm_regs.ARM_pc - 4), NULL);
+        if (errno)
+                return -1;
++
++#if defined(__ARMEB__) && defined(__ARM_ARCH_7A__)
++       /* We running big endian arm on ARMv7: instructions are
++        * in little endian form so we need to byteswap it. Note
++        * on older ARM like V5 Xscale code is in big endian form
++        * byte swap is not needed in this case. I.e be8 vs be32.
++        */
++       scno = __builtin_bswap32(scno);
++#endif /*  __ARMEB__ && __ARM_ARCH_7A__ */
++
+        /* EABI syscall convention? */
+        if (scno != 0xef000000) {
+                /* No, it's OABI */