From: Vitaliy Cherepanov <v.cherepanov@samsung.com>
Date: Tue, 21 Jul 2015 14:45:09 +0000 (+0300)
Subject: [FIX] Preload: use caller address from userspace
X-Git-Tag: submit/tizen_2.4/20150912.103527~50
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=507f8449e88209a6c63161fc471a6789267261d4;p=kernel%2Fswap-modules.git

[FIX] Preload: use caller address from userspace

This is a workaround for Tizen OpenGL probes. We cannot obtain the
expected caller address (i.e. the address in the target binary) from
kernel handlers because GL functions are actually called through
third-party libraries. To handle this situation we now pass the proper
address from userspace handlers.

Change-Id: Ibaa2190aed0c1587fa121feb13536b8ff267e680
Signed-off-by: Vitaliy Cherepanov <v.cherepanov@samsung.com>
---

diff --git a/preload/preload_module.c b/preload/preload_module.c
index 8895ec8..87575f8 100644
--- a/preload/preload_module.c
+++ b/preload/preload_module.c
@@ -758,6 +758,7 @@ static int write_msg_handler(struct kprobe *p, struct pt_regs *regs)
 	size_t len;
 	unsigned long caller_offset;
 	unsigned long call_type_offset;
+	unsigned long caller_addr;
 	bool drop;
 	int ret;
 
@@ -765,6 +766,7 @@ static int write_msg_handler(struct kprobe *p, struct pt_regs *regs)
 	len = swap_get_uarg(regs, 1);
 	call_type_p = (char *)swap_get_uarg(regs, 2);
 	caller_p = (char *)swap_get_uarg(regs, 3);
+	caller_addr = swap_get_uarg(regs, 4);
 
 	ret = __msg_sanitization(user_buf, len, call_type_p, caller_p);
 	if (ret != 0) {
@@ -796,6 +798,10 @@ static int write_msg_handler(struct kprobe *p, struct pt_regs *regs)
 
 	__write_data_to_msg(buf, len, call_type_offset, caller_offset);
 
+	/* FIXME refactor this hack for opengl tizen probes */
+	if (caller_addr)
+		*(uintptr_t *)(buf + caller_offset) = (uintptr_t)caller_addr;
+
 	ret = swap_msg_raw(buf, len);
 	if (ret != len)
 		printk(PRELOAD_PREFIX "Error writing probe lib message\n");