IA64 Stack Unwind on RedHat Linux

Hi All,

In RedHat Linux, I'm working with a software vendor who is looking for information on an API for finding the stack unwind table, provided by the dynamic loader. If this is available now, any information on where to get it and how to use it would be greatly appreciated. If this is not currently available, could someone please provide me with an expected date when it will be, so that the vendor can plan their product roadmap more effectively?

Here's some further clarification of the issue from the software vendor:

The information we need is the procedure/API for finding the unwind table associated with a given instruction pointer under Linux for IA-64. The documentation on IA-64 stack unwinding says this information is necessary for stack unwinding, but is OS-specific and not given in the Intel manuals:
Specifically, in Section 11.1.2 of the IA-64 Software Conventions and Runtime Architecture Guide, it says "...the dynamic loader is expected to provide an API for finding the unwind table, given a known IP. This API is specific to the operating environment, and is not described here."

Here's a description of what they did on Linux/x86:

When someone allocates memory we get a list of address. Each address is the return address to the previous stack frame. The entire list should describe the entire calls stack of the call to "malloc". When an "interesting event" happens to the memory allocated, we go through the list of pointers. For each address we find the relevant symbol, module, and line information if available.

This is roughly what we do on linux/x86

void* getSp() {
asm("mov %ebp, %eax");
}

void *unwindStack() {
void * sp = getSp;
void stack[100];
int i = 0;

// limit is some value beyond which the stack is not interesting while (sp > limit) {
// The return address is the second word of the stack frame stack[i++] = sp + 1;

// The first word of the stack frame is the address of the previous stack frame.
sp = *(void **)sp;
}

return stack;
}
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Thanks for your help,

Brian E. Zorn
Application Engineer Phone: 503-264-6218
Core eTools - Oregon email:
[email protected] <mailto:[email protected]> Solutions Enabling Group
Intel Corporation