On Fri, 2019-06-07 at 15:27 -0700, Andy Lutomirski wrote:

quoted

On Jun 7, 2019, at 2:09 PM, Dave Hansen [off-list ref] wrote:

On 6/7/19 1:06 PM, Yu-cheng Yu wrote:

quoted

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Huh, how does glibc know about all possible past and future legacy code
in the application?

When dlopen() gets a legacy binary and the policy allows that, it will
manage
the bitmap:

 If a bitmap has not been created, create one.
 Set bits for the legacy code being loaded.

I was thinking about code that doesn't go through GLIBC like JITs.

CRIU is another consideration: it would be rather annoying if CET programs
can’t migrate between LA57 and normal machines.

When a machine migrates, does its applications' addresses change?
If no, then the bitmap should still work, right?

Yu-cheng