[PATCH] x86: math-emu: fix div_Xsig prototype

[PATCH] x86: math-emu: fix div_Xsig prototype

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

The third argument of div_Xsig() is the output of the division, but is marked
'const', which means the compiler is not expecting it to be updated and may
generate bad code around the call. clang-21 now warns about the pattern since
an uninitialized variable is passed into two 'const' arguments by reference:

arch/x86/math-emu/poly_atan.c:93:28: error: variable 'argSignif' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer]
   93 |         div_Xsig(&Numer, &Denom, &argSignif);
      |                                   ^~~~~~~~~
arch/x86/math-emu/poly_l2.c:195:29: error: variable 'argSignif' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer]
  195 |                 div_Xsig(&Numer, &Denom, &argSignif);
      |                                           ^~~~~~~~~

The implementation is in assembly, so the problem has gone unnoticed since the
code was added in the linux-1.1 days. Remove the 'const' marker here.

Fixes: e19a1bdb835c ("Import 1.1.38")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/x86/math-emu/poly.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/math-emu/poly.h b/arch/x86/math-emu/poly.h
index fc1c887ca073..654bfe4e29a0 100644
--- a/arch/x86/math-emu/poly.h
+++ b/arch/x86/math-emu/poly.h
@@ -39,7 +39,7 @@ asmlinkage void mul_Xsig_Xsig(Xsig *dest, const Xsig *mult);
 asmlinkage void shr_Xsig(Xsig *, const int n);
 asmlinkage int round_Xsig(Xsig *);
 asmlinkage int norm_Xsig(Xsig *);
-asmlinkage void div_Xsig(Xsig *x1, const Xsig *x2, const Xsig *dest);
+asmlinkage void div_Xsig(Xsig *x1, const Xsig *x2, Xsig *dest);
 
 /* Macro to extract the most significant 32 bits from a long long */
 #define LL_MSW(x)     (((unsigned long *)&x)[1])
-- 
2.39.5