The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 1cec9ac2d071cfd2da562241aab0ef701355762a # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025081251-sitter-agreed-26a4@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 1cec9ac2d071cfd2da562241aab0ef701355762a Mon Sep 17 00:00:00 2001 From: Dave Hansen dave.hansen@linux.intel.com Date: Tue, 24 Jun 2025 14:01:48 -0700 Subject: [PATCH] x86/fpu: Delay instruction pointer fixup until after warning
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 dave.hansen@linux.intel.com Reviewed-by: Chao Gao chao.gao@intel.com Acked-by: Alison Schofield alison.schofield@intel.com Acked-by: Peter Zijlstra (Intel) peterz@infradead.org Cc:stable@vger.kernel.org Link: https://lore.kernel.org/all/20250624210148.97126F9E%40davehans-spike.ostc.in...
diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index bf8dab18be97..2fdc1f1f5adb 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -122,13 +122,12 @@ static bool ex_handler_sgx(const struct exception_table_entry *fixup, static bool ex_handler_fprestore(const struct exception_table_entry *fixup, struct pt_regs *regs) { - regs->ip = ex_fixup_addr(fixup); - WARN_ONCE(1, "Bad FPU state detected at %pB, reinitializing FPU registers.", (void *)instruction_pointer(regs));
fpu_reset_from_exception_fixup(); - return true; + + return ex_handler_default(fixup, regs); }
/*