[Adding CC list of original patch plus regression tracker]
Hi Jason,
On 18.04.24 13:48, Jason A. Donenfeld wrote:
This reverts commit ad6bcdad2b6724e113f191a12f859a9e8456b26d. I had
nak'd it, and Greg said on the thread that it links that he wasn't going
to take it either, especially since it's not his code or his tree, but
then, seemingly accidentally, it got pushed up some months later, in
what looks like a mistake, with no further discussion in the linked
thread. So revert it, since it's clearly not intended.
Reverting this patch creates a user space visible regression compared to
v6.8. Please treat it as such.
I'm slightly confused to see you passionate about this patch after you
ghosted the conversation you referenced:
https://lore.kernel.org/lkml/00d6172f-e291-4e96-9d3e-63ee8e60d556@xxxxxxxxxx/
The purpose of this uevent is to notify systemd[1][2] (or similar) that
a VM clone event happened, so it can for example regenerate MAC
addresses if it generated them on boot, regenerate its unique machine id
or simply force rerequest a new DHCP lease.
I don't understand how there's any correlation or dependency to
vgetrandom() or anything RNG in this and why getting vgetrandom() merged
upstream is even something to talk about in the same line as this patch [3].
We had a lengthy, constructive conversation with Ted at LPC last year
about the "PRNG and clone" use case and concluded that it's best for
everyone to simply assume the system could be cloned at any point, hence
always force intermix of RDRAND or comparable to any PRNG output. We
since no longer need an event for that case.
Alex
[1] https://github.com/systemd/systemd/issues/26380
[2] https://lore.kernel.org/lkml/ZJGNREN4tLzQXOJr@gardel-login/
[3]
https://lore.kernel.org/lkml/CAHmME9pxc-nO_xa=4+1CnvbnuefbRTJHxM7n817c_TPeoxzu_g@xxxxxxxxxxxxxx/
#regzbot introduced: 3aadf100f93d8081
Fixes: ad6bcdad2b67 ("vmgenid: emit uevent when VMGENID updates")
Cc: stable@xxxxxxxxxxxxxxx
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230531095119.11202-2-bchalios@xxxxxxxxx
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
---
drivers/virt/vmgenid.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/virt/vmgenid.c b/drivers/virt/vmgenid.c
index b67a28da4702..a1c467a0e9f7 100644
--- a/drivers/virt/vmgenid.c
+++ b/drivers/virt/vmgenid.c
@@ -68,7 +68,6 @@ static int vmgenid_add(struct acpi_device *device)
static void vmgenid_notify(struct acpi_device *device, u32 event)
{
struct vmgenid_state *state = acpi_driver_data(device);
- char *envp[] = { "NEW_VMGENID=1", NULL };
u8 old_id[VMGENID_SIZE];
memcpy(old_id, state->this_id, sizeof(old_id));
@@ -76,7 +75,6 @@ static void vmgenid_notify(struct acpi_device *device, u32 event)
if (!memcmp(old_id, state->this_id, sizeof(old_id)))
return;
add_vmfork_randomness(state->this_id, sizeof(state->this_id));
- kobject_uevent_env(&device->dev.kobj, KOBJ_CHANGE, envp);
}
static const struct acpi_device_id vmgenid_ids[] = {
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