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x86/math-emu: Fix div_Xsig() prototype

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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>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20250807205334.123231-1-arnd@kernel.org
This commit is contained in:
Arnd Bergmann
2025-08-07 22:53:28 +02:00
committed by Borislav Petkov (AMD)
parent 6146a0f1df
commit 780813d701
1 changed files with 1 additions and 1 deletions
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arch/x86/math-emu/poly.h
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@@ -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])