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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?YoBVRlrRYijkPtB3/4o9iosLkl3IduAm6bxCEdZ6ucCKXYK1eGPYTQjtoKEM?= =?us-ascii?Q?P6wDgD4R3Td6f8nRrL05bx8QY8A7YJJMxEHoZ8wTUPKZWMyjnvnkoJJ3TICF?= =?us-ascii?Q?TO+t/PaWoDvyBmOQHJ7IFBPicWN/uS6PEwXT+/e+dJiCBgmxcFKk5adN2Xes?= =?us-ascii?Q?qz/zl/NoVzMUHx5KNU05JSd5IvpTMgvaJ0X0BlNcRXOPUynYHmriBkEZNWeQ?= =?us-ascii?Q?hNWkvauzVi1y5baxU1GrV4GczGn7cqw0hBbkE57lK18V+vnG959ZJY287mCL?= =?us-ascii?Q?/fNia6Fo0HA2NdmvpjHgbIHNhYN7qg1soiS/4KLZi+28xuYK2N3EzxiVvrJG?= =?us-ascii?Q?4ngqFUva6Gjl4JVjSu2g/SENh8liLEXk/MlFZ4ypXhsrg2CpknS/ljxBI7zn?= =?us-ascii?Q?KfnoK1yR5F5XtqcKzSy+ua2F/pYYvz3xu7SrXjO7ojxc1Z/IF/ldIh/CJmfu?= =?us-ascii?Q?Or8cxvZo5F+qPXGaAPWKnDwOdOLcbJVVkUTGnEe63SbJ6/nYue6KqlEQ3mCI?= =?us-ascii?Q?6FdHGDVOSpnoTACxulQchbr73rI4a22xMOjnhwsxGxm7s0/YFl6FgFYItxg9?= =?us-ascii?Q?eslLdzLh/YFfsEpJOdEnx23iytWPRqRZkno1R/VZSOmMZP32SSqlC0kNWVC8?= =?us-ascii?Q?U6ax9kjYhlfWfPgJXeUkD01Wpo0z0UmyE5ZnDDRBZywlx5g1FaZHsS0KdQm0?= =?us-ascii?Q?jlFxljIg4+FyAb7RSYMz+icuiLlSwTJAkHFahOm5bRlHTshf/zOlj9zaA/9+?= =?us-ascii?Q?ozF9B3sAd57pJmTT8cb3brrgwObzVM6i0Ln8VR5g55BoeCGl8nf24P5IDfBe?= =?us-ascii?Q?iIVOAtgzBmmlCTWZxjT+ko29GxhiCyU90XSTG94scDY0Vsb9ZzLf//ygB2tb?= =?us-ascii?Q?tytE0gFIwewuEwviB3SsOIzXAMbSoRArAUqBCmeT0UTiqwT29nXbEYFWqO/E?= =?us-ascii?Q?avnTPfrFxyF0zRr4Wh87wqLKxKhZq8vXOvgjohh5cm8RPznxcOD0oefaw/WU?= =?us-ascii?Q?6EsbN7dKHEcOOtW1w/joXfKNFm5PDp0OqjUKgxYSwOwHbZCwxk789erxKset?= =?us-ascii?Q?PIciXCoc+RK3HvTP2U4ulIO0nnRiWVU4PIa4M0kGNGUue41nIrTG2J7nDZGG?= =?us-ascii?Q?z/r9uUwG5CirfZvwWpoZ1kGwHmhCLzLhphn/Gq+Y/pZnQocf4+6cm/Sj1Zkz?= =?us-ascii?Q?OV7DZI3UbHBeckuX60TftbRoAiUvVBOWACc4V9QHxUjo8t1l2CRkrkUMCnLI?= =?us-ascii?Q?VewPPSgSrIoqd+NpKtB3lBUUcrbga/1zLFUSFESNzUYZMxoWvbN+KqFkuQVX?= =?us-ascii?Q?p8eiI1RjzTo/HQ2hRigY7HgzVeKnphaoI2y6J8vj4llcU1s/OEqbTO1gd1w9?= =?us-ascii?Q?GSygKzw8Uo1Nd+r7CCGDRsXbPZa1GdsFCxymcW6RwEl4gNWxkqqDnUHrRTk3?= =?us-ascii?Q?uqFtYHmCIW2kt5hbJB03J3KmLN9RusiibVbI0bC+AD/KCznlRWbZYHiTEwTH?= =?us-ascii?Q?0KO5l2UUdtFiNZzpIwdlQBUHTmBUYOZSWAdBujM1o8fy3fdlPCsxNyQLdBJ8?= =?us-ascii?Q?mGBqPOXb0osN+BBt5VuPxNiSq9CUgXp2m1o5NQpw?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: ef5b42f3-c072-4d1a-3e18-08dda90f2824 X-MS-Exchange-CrossTenant-AuthSource: DM4PR12MB6373.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 11 Jun 2025 17:41:12.3957 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: gZ1eAWDAchbPkP68zlX1dFIi9dcN8fbiTXxiuVTABbxbVBEHtA719PyJizhHP1Rum9rmRYsI7RQFpkWras/OYg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA0PR12MB8745 On Sat, May 31, 2025 at 03:00:14PM -0700, Luck, Tony wrote: > On Sat, May 31, 2025 at 09:07:24PM +0200, Borislav Petkov wrote: > > On Sat, May 31, 2025 at 08:04:58PM +0200, Ingo Molnar wrote: > > > What tool? > > > > mce-inject. The module. > > > > > Or if you mean the MCE-injection interface, that's not supposed to > > > trigger avoidable crashes either, it's an injection facility for > > > testing purposes: > > > > That's an injection facility to TEST THE MCE PANIC PATHS too. YES, IT VERY MUCH > > SHOULD TRIGGER CRASHES! That is actually a feature! > > > > I have fixed bugs in the MCE handler exactly because an MCE signature gets > > injected unfettered. > > > > > It's really simple really: > > > > > > - If the kernel unnecessarily locks up on the receipt of a > > > hardware-generated MCE then that's a kernel bug that > > > should be fixed. > > > > This is not a hw generated MCE - this is a user-generated MCE signature. > > I think you're confusing things here. > > > > > - If the kernel unnecessarily locks up on the receipt of a > > > software-generated MCE then that's a kernel bug that > > > should be fixed. > > > > No, it isn't. I can inject a MCE which will lock up the whole machine. And > > that's a valid MCE which can also be raised by hw. > > > > > TL;DR, this is not an acceptable kernel response: > > > > It is very much a valid kernel response. The MCE injection module allows for > > testing the MCE panic path with all that is involved in it, including the > > machine dying. > > > > Yes, because MCE is special and it can and *should* cause panics. > > > > So for patches like this one which is masssaging the MCE - and which is also > > wrong for other reasons - not every Intel uarch supports local MCEs: > > > > NAK! > > I'm solidly with Boris on this one. I don't want mce-inject to sanity > check, or second guess and "fix" the signature that I requested. I want > it to do what I asked it to do. > > 1) Sometimes I want to force a crash from a particular signature because > I want to check that Linux accurately logs the signature of the error > that I injected. > > 2) Sometimes I want to inject "impossible" signatures that can't happen > on any CPU today, but I know will be a recoverable error on a future > processor. That's how much of the early machine check recovery code was > developed and tested. > Additionally, we have a "fake_panic" parameter/debugfs entry that lets us test the panic path without truly bringing down the system. Thanks, Yazen