From nobody Sat Feb 7 15:47:16 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 00EAD2BB03; Tue, 13 Feb 2024 09:56:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707818198; cv=none; b=NkvBj1BrSCpbRlMfHcd4mXtv9JtPYXGmY7T9tbMmaubbDPPX292w1W5CMW5FNyMS+aTJ++D1mzjBvbkhLFkoLRdq7VY0Lp5011YvXl7PRBKRqxNbQxYCBZ4DFwlO7oXtNsAzalIyXBPTeypD61B2PxFU1jm2BXjS59Dr6kxMuUU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707818198; c=relaxed/simple; bh=vb+KBTnTSXAaZj4rUNtfS8bhDG7fD2FUJ5wHxmolX/E=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=fmgzXFa51Ne0/9oRsGdNgC0btrCLDyBdEoq/cFdGCMtAHiChlIs1XghMfLZt1sEpfbDI5GiO5OXfjt8nNsKygG7w+xJR4M5g8f6rjKoQPXUtZIARVbjZn+Vqlqjth8T2yaLCfucua95slO8wNXWUusNNIR0IF22QxQdVCzqxtpo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VJt5Is3z; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VJt5Is3z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6B311C433F1; Tue, 13 Feb 2024 09:56:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707818197; bh=vb+KBTnTSXAaZj4rUNtfS8bhDG7fD2FUJ5wHxmolX/E=; h=From:To:Cc:Subject:Date:From; b=VJt5Is3zeq/Zjfhdhjq8lEVPdZGh9L98WDNDPu7YIB/pra9bf1JMk+PkxRtLD72Gp mteiCp8/9APkYVFjHL3prsi4G+T3O/kR4aasJs7NxYovDHmx5aHQOP+3qDUjD92tOB Vjgw2uq3LJ77tCCvbEEOdYkY3ObnM0ABaKvIS3cAZSF1CrJwiUI79HYWUI5QUXY3kD cdf37TIDn/ZXNojU9QUqRlEFdMWp9Grs0c2n/GdVTHH1mu6AFk9B6VuAQP7EWsJPxh v6AXbU/kPsJj5dpXWOtVEuvYE4uZUwJ5Ve10QMBCCrpfX3SW1MGoxsNVITLP2LvVbM BWv8cg4PPfTqg== From: Arnd Bergmann To: Bill Metzenthen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: Arnd Bergmann , "H. Peter Anvin" , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt , linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH] x86: math-emu: fix function cast warnings Date: Tue, 13 Feb 2024 10:56:18 +0100 Message-Id: <20240213095631.454543-1-arnd@kernel.org> X-Mailer: git-send-email 2.39.2 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Arnd Bergmann clang-16 warns about casting function pointers with incompatible prototypes. The x86 math-emu code does this in a number of places to call some trivial functions that need no arguments: arch/x86/math-emu/fpu_etc.c:124:14: error: cast from 'void (*)(void)' to 'F= UNC_ST0' (aka 'void (*)(struct fpu__reg *, unsigned char)') converts to inc= ompatible function type [-Werror,-Wcast-function-type-strict] 124 | fchs, fabs, (FUNC_ST0) FPU_illegal, (FUNC_ST0) FPU_illegal, | ^~~~~~~~~~~~~~~~~~~~~~ arch/x86/math-emu/fpu_trig.c:1634:19: error: cast from 'void (*)(void)' to = 'FUNC_ST0' (aka 'void (*)(struct fpu__reg *, unsigned char)') converts to i= ncompatible function type [-Werror,-Wcast-function-type-strict] 1634 | fxtract, fprem1, (FUNC_ST0) fdecstp, (FUNC_ST0) fincstp | ^~~~~~~~~~~~~~~~~~ arch/x86/math-emu/reg_constant.c:112:53: error: cast from 'void (*)(void)' = to 'FUNC_RC' (aka 'void (*)(int)') converts to incompatible function type [= -Werror,-Wcast-function-type-strict] 112 | fld1, fldl2t, fldl2e, fldpi, fldlg2, fldln2, fldz, (FUNC_RC= ) FPU_illegal Change the fdecstp() and fincstp() functions to actually have the correct prototypes based on the caller, and add wrappers around FPU_illegal() for adapting those. Signed-off-by: Arnd Bergmann --- arch/x86/math-emu/fpu_etc.c | 9 +++++++-- arch/x86/math-emu/fpu_trig.c | 6 +++--- arch/x86/math-emu/reg_constant.c | 7 ++++++- 3 files changed, 16 insertions(+), 6 deletions(-) diff --git a/arch/x86/math-emu/fpu_etc.c b/arch/x86/math-emu/fpu_etc.c index 1b118fd93140..39423ec409e1 100644 --- a/arch/x86/math-emu/fpu_etc.c +++ b/arch/x86/math-emu/fpu_etc.c @@ -120,9 +120,14 @@ static void fxam(FPU_REG *st0_ptr, u_char st0tag) setcc(c); } =20 +static void FPU_ST0_illegal(FPU_REG *st0_ptr, u_char st0_tag) +{ + FPU_illegal(); +} + static FUNC_ST0 const fp_etc_table[] =3D { - fchs, fabs, (FUNC_ST0) FPU_illegal, (FUNC_ST0) FPU_illegal, - ftst_, fxam, (FUNC_ST0) FPU_illegal, (FUNC_ST0) FPU_illegal + fchs, fabs, FPU_ST0_illegal, FPU_ST0_illegal, + ftst_, fxam, FPU_ST0_illegal, FPU_ST0_illegal, }; =20 void FPU_etc(void) diff --git a/arch/x86/math-emu/fpu_trig.c b/arch/x86/math-emu/fpu_trig.c index 990d847ae902..85daf98c81c3 100644 --- a/arch/x86/math-emu/fpu_trig.c +++ b/arch/x86/math-emu/fpu_trig.c @@ -433,13 +433,13 @@ static void fxtract(FPU_REG *st0_ptr, u_char st0_tag) #endif /* PARANOID */ } =20 -static void fdecstp(void) +static void fdecstp(FPU_REG *st0_ptr, u_char st0_tag) { clear_C1(); top--; } =20 -static void fincstp(void) +static void fincstp(FPU_REG *st0_ptr, u_char st0_tag) { clear_C1(); top++; @@ -1631,7 +1631,7 @@ static void fscale(FPU_REG *st0_ptr, u_char st0_tag) =20 static FUNC_ST0 const trig_table_a[] =3D { f2xm1, fyl2x, fptan, fpatan, - fxtract, fprem1, (FUNC_ST0) fdecstp, (FUNC_ST0) fincstp + fxtract, fprem1, fdecstp, fincstp, }; =20 void FPU_triga(void) diff --git a/arch/x86/math-emu/reg_constant.c b/arch/x86/math-emu/reg_const= ant.c index 742619e94bdf..003a0b2753e6 100644 --- a/arch/x86/math-emu/reg_constant.c +++ b/arch/x86/math-emu/reg_constant.c @@ -108,8 +108,13 @@ static void fldz(int rc) =20 typedef void (*FUNC_RC) (int); =20 +static void FPU_RC_illegal(int unused) +{ + FPU_illegal(); +} + static FUNC_RC constants_table[] =3D { - fld1, fldl2t, fldl2e, fldpi, fldlg2, fldln2, fldz, (FUNC_RC) FPU_illegal + fld1, fldl2t, fldl2e, fldpi, fldlg2, fldln2, fldz, FPU_RC_illegal }; =20 void fconst(void) --=20 2.39.2