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RTM/HLE abort on stack pointer mod

Oliver_K_
Beginner
158 Views

Hi,

to be confirmed: modification on stack pointer register (RSP/ESP) will not abort HLE/RTM?!

ty,

Oliver

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5 Replies
James_C_Intel2
Employee
158 Views

 modification on stack pointer register (RSP/ESP) will not abort HLE/RTM?!

Of course it won't abort.  It's just a register like any other from the TSX hardware's point of view.

(If you couldn't modify it you'd be unable to use the call or ret instructions inside a speculative region!)

Oliver_K_
Beginner
158 Views

I assume the same is true for exchanging the complete stack (e.g. assigning address from a complete different address range than the current one points to).

James_C_Intel2
Employee
158 Views

I assume the same is true for exchanging the complete stack (e.g. assigning address from a complete different address range than the current one points to)

As before : " It's just a register like any other from the TSX hardware's point of view." So you can put whatever you like into it, and the hardware doesn't care. 

jimdempseyatthecove
Black Belt
158 Views

James,

While changing the content of the stack pointer would not terminate the transaction, using the stack could when the access causes a page fault. This may be relatively rare after the first use of the specific page(s) of stack address space.

Jim Dempsey

James_C_Intel2
Employee
158 Views

While changing the content of the stack pointer would not terminate the transaction, using the stack could when the access causes a page fault. 

Of course, but so could any memory access, so I see that as a different concern. 

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