From patchwork Thu Oct 25 06:43:30 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [3/3] kgdb/kgdbts: support ppc64 Date: Wed, 24 Oct 2012 20:43:30 -0000 From: Tiejun Chen X-Patchwork-Id: 194060 Message-Id: <1351147410-17452-3-git-send-email-tiejun.chen@windriver.com> To: Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, jason.wessel@windriver.com We can't look up the address of the entry point of the function simply via that function symbol for all architectures. For PPC64 ABI, actually there is a function descriptors structure. A function descriptor is a three doubleword data structure that contains the following values: * The first doubleword contains the address of the entry point of the function. * The second doubleword contains the TOC base address for the function. * The third doubleword contains the environment pointer for languages such as Pascal and PL/1. So we should call a wapperred dereference_function_descriptor() to get the address of the entry point of the function. Note this is also safe for other architecture after refer to "include/asm-generic/sections.h" since: dereference_function_descriptor(p) always is (p) if without arched definition. Signed-off-by: Tiejun Chen --- drivers/misc/kgdbts.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c index 3aa9a96..4799e1f 100644 --- a/drivers/misc/kgdbts.c +++ b/drivers/misc/kgdbts.c @@ -103,6 +103,7 @@ #include #include #include +#include #define v1printk(a...) do { \ if (verbose) \ @@ -222,6 +223,7 @@ static unsigned long lookup_addr(char *arg) addr = (unsigned long)do_fork; else if (!strcmp(arg, "hw_break_val")) addr = (unsigned long)&hw_break_val; + addr = (unsigned long )dereference_function_descriptor((void *)addr); return addr; }