From 550e12ef14b81fedea028b182139450c410c0eda Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Wed, 13 Aug 2025 12:42:19 -0400 Subject: [PATCH] x86/fpu: Delay instruction pointer fixup until after warning [ Upstream commit 1cec9ac2d071cfd2da562241aab0ef701355762a ] Right now, if XRSTOR fails a console message like this is be printed: Bad FPU state detected at restore_fpregs_from_fpstate+0x9a/0x170, reinitializing FPU registers. However, the text location (...+0x9a in this case) is the instruction *AFTER* the XRSTOR. The highlighted instruction in the "Code:" dump also points one instruction late. The reason is that the "fixup" moves RIP up to pass the bad XRSTOR and keep on running after returning from the #GP handler. But it does this fixup before warning. The resulting warning output is nonsensical because it looks like the non-FPU-related instruction is #GP'ing. Do not fix up RIP until after printing the warning. Do this by using the more generic and standard ex_handler_default(). Fixes: d5c8028b4788 ("x86/fpu: Reinitialize FPU registers if restoring FPU state fails") Signed-off-by: Dave Hansen Reviewed-by: Chao Gao Acked-by: Alison Schofield Acked-by: Peter Zijlstra (Intel) Cc:stable@vger.kernel.org Link: https://lore.kernel.org/all/20250624210148.97126F9E%40davehans-spike.ostc.intel.com [ adapted ex_handler_default() call ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/extable.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index 30bb0bd3b1b8..ae7e056d0007 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -59,13 +59,12 @@ __visible bool ex_handler_fprestore(const struct exception_table_entry *fixup, unsigned long error_code, unsigned long fault_addr) { - regs->ip = ex_fixup_addr(fixup); - WARN_ONCE(1, "Bad FPU state detected at %pB, reinitializing FPU registers.", (void *)instruction_pointer(regs)); __copy_kernel_to_fpregs(&init_fpstate, -1); - return true; + + return ex_handler_default(fixup, regs, trapnr, error_code, fault_addr); } EXPORT_SYMBOL_GPL(ex_handler_fprestore);