The following commit has been merged into the x86/fpu branch of tip:

Commit-ID: 48280042f2c6e3ac2cfb1d8b752ab4a7e0baea24 Gitweb: https://git.kernel.org/tip/48280042f2c6e3ac2cfb1d8b752ab4a7e0baea24 Author: Andrew Cooper andrew.cooper3@citrix.com AuthorDate: Wed, 10 Aug 2022 23:19:09 +01:00 Committer: Borislav Petkov bp@suse.de CommitterDate: Wed, 09 Nov 2022 13:28:31 +01:00

x86/fpu/xstate: Fix XSTATE_WARN_ON() to emit relevant diagnostics

"XSAVE consistency problem" has been reported under Xen, but that's the extent of my divination skills.

Modify XSTATE_WARN_ON() to force the caller to provide relevant diagnostic information, and modify each caller suitably.

For check_xstate_against_struct(), this removes a double WARN() where one will do perfectly fine.

CC stable as this has been wonky debugging for 7 years and it is good to have there too.

Signed-off-by: Andrew Cooper andrew.cooper3@citrix.com Signed-off-by: Borislav Petkov bp@suse.de Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220810221909.12768-1-andrew.cooper3@citrix.com --- arch/x86/kernel/fpu/xstate.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 59e543b..c2dde46 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -440,8 +440,8 @@ static void __init __xstate_dump_leaves(void) } }

-#define XSTATE_WARN_ON(x) do { \ - if (WARN_ONCE(x, "XSAVE consistency problem, dumping leaves")) { \ +#define XSTATE_WARN_ON(x, fmt, ...) do { \ + if (WARN_ONCE(x, "XSAVE consistency problem: " fmt, ##__VA_ARGS__)) { \ __xstate_dump_leaves(); \ } \ } while (0) @@ -554,8 +554,7 @@ static bool __init check_xstate_against_struct(int nr) (nr >= XFEATURE_MAX) || (nr == XFEATURE_PT_UNIMPLEMENTED_SO_FAR) || ((nr >= XFEATURE_RSRVD_COMP_11) && (nr <= XFEATURE_RSRVD_COMP_16))) { - WARN_ONCE(1, "no structure for xstate: %d\n", nr); - XSTATE_WARN_ON(1); + XSTATE_WARN_ON(1, "No structure for xstate: %d\n", nr); return false; } return true; @@ -598,12 +597,13 @@ static bool __init paranoid_xstate_size_valid(unsigned int kernel_size) * XSAVES. */ if (!xsaves && xfeature_is_supervisor(i)) { - XSTATE_WARN_ON(1); + XSTATE_WARN_ON(1, "Got supervisor feature %d, but XSAVES not advertised\n", i); return false; } } size = xstate_calculate_size(fpu_kernel_cfg.max_features, compacted); - XSTATE_WARN_ON(size != kernel_size); + XSTATE_WARN_ON(size != kernel_size, + "size %u != kernel_size %u\n", size, kernel_size); return size == kernel_size; }