1 files changed, 53 insertions, 0 deletions
diff --git a/third_party/rust/crash-context/src/linux/getcontext/x86.rs b/third_party/rust/crash-context/src/linux/getcontext/x86.rs
new file mode 100644
index 0000000000..b9d4b5ab72
--- /dev/null
+++ b/third_party/rust/crash-context/src/linux/getcontext/x86.rs
@@ -0,0 +1,53 @@
+#[cfg(target_os = "android")]
+compile_error!("please file an issue if you care about this target");
+
+std::arch::global_asm! {
+    ".text",
+    ".global crash_context_getcontext",
+    ".hidden crash_context_getcontext",
+    ".align 4",
+    ".type crash_context_getcontext, @function",
+"crash_context_getcontext:",
+    "movl 4(%esp), %eax",   // eax = uc
+
+    // Save register values
+    "movl %ecx, 0x3c(%eax)",
+    "movl %edx, 0x38(%eax)",
+    "movl %ebx, 0x34(%eax)",
+    "movl %edi, 0x24(%eax)",
+    "movl %esi, 0x28(%eax)",
+    "movl %ebp, 0x2c(%eax)",
+
+    "movl (%esp), %edx",   /* return address */
+    "lea  4(%esp), %ecx",  /* exclude return address from stack */
+    "mov  %edx, 0x4c(%eax)",
+    "mov  %ecx, 0x30(%eax)",
+
+    "xorl %ecx, %ecx",
+    "movw %fs, %cx",
+    "mov  %ecx, 0x18(%eax)",
+
+    "movl $0, 0x40(%eax)",
+
+    // Save floating point state to fpregstate, then update
+    // the fpregs pointer to point to it
+    "leal 0xec(%eax), %ecx",
+    "fnstenv (%ecx)",
+    "fldenv  (%ecx)",
+    "mov %ecx, 0x60(%eax)",
+
+    // Save signal mask: sigprocmask(SIGBLOCK, NULL, &uc->uc_sigmask)
+    "leal 0x6c(%eax), %edx",
+    "xorl %ecx, %ecx",
+    "push %edx",   /* &uc->uc_sigmask */
+    "push %ecx",   /* NULL */
+    "push %ecx",   /* SIGBLOCK == 0 on i386 */
+    "call sigprocmask@PLT",
+    "addl $12, %esp",
+
+    "movl $0, %eax",
+    "ret",
+
+    ".size crash_context_getcontext, . - crash_context_getcontext",
+    options(att_syntax)
+}