From 6b3bab39d128947bf51deefe6a28c247cafd7bae Mon Sep 17 00:00:00 2001
From: Elliott Hughes <enh@google.com>
Date: Mon, 21 May 2012 13:59:52 -0700
Subject: [PATCH] Fix libcorkscrew for x86 targets (bionic) as well as the host
 (glibc).

Longer term, we might want to offer <ucontext.h> and have that be like glibc's,
but not today. (Note that POSIX says nothing about mcontext_t and glibc,
Mac OS, and the Linux kernel headers are all mutually incompatible.)

Change-Id: Ia074b51f4567cd54e06bbe29721389c8d1278614
---
 libcorkscrew/arch-x86/backtrace-x86.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/libcorkscrew/arch-x86/backtrace-x86.c b/libcorkscrew/arch-x86/backtrace-x86.c
index a568c6d93..01d9ed596 100644
--- a/libcorkscrew/arch-x86/backtrace-x86.c
+++ b/libcorkscrew/arch-x86/backtrace-x86.c
@@ -33,9 +33,21 @@
 #include <sys/ptrace.h>
 #include <cutils/log.h>
 
+#if defined(__BIONIC__)
+
+// Bionic offers the Linux kernel headers.
+#include <asm/sigcontext.h>
+#include <asm/ucontext.h>
+typedef struct ucontext ucontext_t;
+
+#else
+
+// glibc has its own renaming of the Linux kernel's structures.
 #define __USE_GNU // For REG_EBP, REG_ESP, and REG_EIP.
 #include <ucontext.h>
 
+#endif
+
 /* Unwind state. */
 typedef struct {
     uint32_t ebp;
@@ -84,9 +96,15 @@ ssize_t unwind_backtrace_signal_arch(siginfo_t* siginfo, void* sigcontext,
     const ucontext_t* uc = (const ucontext_t*)sigcontext;
 
     unwind_state_t state;
+#if defined(__BIONIC__)
+    state.ebp = uc->uc_mcontext.ebp;
+    state.esp = uc->uc_mcontext.esp;
+    state.eip = uc->uc_mcontext.eip;
+#else
     state.ebp = uc->uc_mcontext.gregs[REG_EBP];
     state.esp = uc->uc_mcontext.gregs[REG_ESP];
     state.eip = uc->uc_mcontext.gregs[REG_EIP];
+#endif
 
     memory_t memory;
     init_memory(&memory, map_info_list);