[PATCH v6 0/9] Add support for memory sealing

[Yury Khrustalev]

Hi Adhemerval,

On Tue, Mar 11, 2025 at 02:09:47PM -0300, Adhemerval Zanella wrote:
> The Linux 6.10 (8be7258aad44) added the mseal syscall that allows
> blocking some memory mapping operations on the VMA range:
> 

At least 4 tests fail due to BTI detecting mismatch when the binaries for these tests
are built with `-Wl,-z,memory-seal`:

FAIL: elf/filter
FAIL: elf/tst-big-note
FAIL: elf/tst-relr3
FAIL: elf/tst-relr4

To reproduce this, you need to enable BTI support by using `-mbranch-protection=bti`
and you also need a system that supports BTI, and of course configure Glibc with
`--enable-memory-sealing`.

I used the FVP model following this guide [1].

I will need more time to get to the bottom of where and why this happens. Disabling
either BTI (e.g. on kernel level) or memory sealing solves this issue, so it seems
that these two are not compatible yet.

[1] https://inbox.sourceware.org/libc-help/Z9grjmNzxsuPu7iD@arm.com/

Kind regards,
Yury