The SVE context block in the signal frame needs to be considered too when computing the maximum possible signal frame size.
Because the size of this block depends on the vector length, this patch computes the size based not on the thread's current vector length but instead on the maximum possible vector length: this determines the maximum size of SVE context block that can be observed in any signal frame for the lifetime of the process. Signed-off-by: Dave Martin <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Alex Bennée <[email protected]> --- arch/arm64/kernel/signal.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 3382e87..15bc2ad 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -595,8 +595,18 @@ static int setup_sigframe_layout(struct rt_sigframe_user_layout *user, if (system_supports_sve()) { unsigned int vq = 0; - if (test_thread_flag(TIF_SVE)) - vq = sve_vq_from_vl(current->thread.sve_vl); + if (add_all || test_thread_flag(TIF_SVE)) { + int vl = sve_max_vl; + + if (!add_all) + vl = current->thread.sve_vl; + + /* Fail safe if something wasn't initialised */ + if (WARN_ON(!sve_vl_valid(vl))) + vl = SVE_VL_MIN; + + vq = sve_vq_from_vl(vl); + } err = sigframe_alloc(user, &user->sve_offset, SVE_SIG_CONTEXT_SIZE(vq)); -- 2.1.4 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
