From 2e4bb98a0e52acbb2da4ae441b89a568af26adf8 Mon Sep 17 00:00:00 2001 From: Edjunior Barbosa Machado Date: Mon, 8 Sep 2014 13:37:23 -0300 Subject: [PATCH] Fix ppc_collect/supply_ptrace_register() routines This patch fixes the routines to collect and supply ptrace registers on ppc64le gdbserver. Originally written for big endian arch, they were causing several issues on little endian. With this fix, the number of unexpected failures in the testsuite dropped from 263 to 72 on ppc64le. gdb/gdbserver/ChangeLog * linux-ppc-low.c (ppc_collect_ptrace_register): Adjust routine to take endianness into account. (ppc_supply_ptrace_register): Likewise. --- gdb/gdbserver/ChangeLog | 6 +++++ gdb/gdbserver/linux-ppc-low.c | 45 ++++++++++++++++++++++++++++------- 2 files changed, 42 insertions(+), 9 deletions(-) diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index 3fb143c2cb..c860daf172 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,3 +1,9 @@ +2014-09-08 Edjunior Barbosa Machado + + * linux-ppc-low.c (ppc_collect_ptrace_register): Adjust routine to take + endianness into account. + (ppc_supply_ptrace_register): Likewise. + 2014-09-03 James Hogan * linux-mips-low.c (mips_read_description): Reset errno to 0 prior diff --git a/gdb/gdbserver/linux-ppc-low.c b/gdb/gdbserver/linux-ppc-low.c index d743311837..8fd4b386ee 100644 --- a/gdb/gdbserver/linux-ppc-low.c +++ b/gdb/gdbserver/linux-ppc-low.c @@ -202,25 +202,52 @@ ppc_cannot_fetch_register (int regno) static void ppc_collect_ptrace_register (struct regcache *regcache, int regno, char *buf) { - int size = register_size (regcache->tdesc, regno); - memset (buf, 0, sizeof (long)); - if (size < sizeof (long)) - collect_register (regcache, regno, buf + sizeof (long) - size); + if (__BYTE_ORDER == __LITTLE_ENDIAN) + { + /* Little-endian values always sit at the left end of the buffer. */ + collect_register (regcache, regno, buf); + } + else if (__BYTE_ORDER == __BIG_ENDIAN) + { + /* Big-endian values sit at the right end of the buffer. In case of + registers whose sizes are smaller than sizeof (long), we must use a + padding to access them correctly. */ + int size = register_size (regcache->tdesc, regno); + + if (size < sizeof (long)) + collect_register (regcache, regno, buf + sizeof (long) - size); + else + collect_register (regcache, regno, buf); + } else - collect_register (regcache, regno, buf); + perror_with_name ("Unexpected byte order"); } static void ppc_supply_ptrace_register (struct regcache *regcache, int regno, const char *buf) { - int size = register_size (regcache->tdesc, regno); - if (size < sizeof (long)) - supply_register (regcache, regno, buf + sizeof (long) - size); + if (__BYTE_ORDER == __LITTLE_ENDIAN) + { + /* Little-endian values always sit at the left end of the buffer. */ + supply_register (regcache, regno, buf); + } + else if (__BYTE_ORDER == __BIG_ENDIAN) + { + /* Big-endian values sit at the right end of the buffer. In case of + registers whose sizes are smaller than sizeof (long), we must use a + padding to access them correctly. */ + int size = register_size (regcache->tdesc, regno); + + if (size < sizeof (long)) + supply_register (regcache, regno, buf + sizeof (long) - size); + else + supply_register (regcache, regno, buf); + } else - supply_register (regcache, regno, buf); + perror_with_name ("Unexpected byte order"); } -- 2.34.1