[PATCH] powerpc/math: Fix missing __user qualifier for get_user() and other sparse warnings

Sparse reports the following problems:

arch/powerpc/math-emu/math.c:228:21: warning: Using plain integer as NULL pointer
arch/powerpc/math-emu/math.c:228:31: warning: Using plain integer as NULL pointer
arch/powerpc/math-emu/math.c:228:41: warning: Using plain integer as NULL pointer
arch/powerpc/math-emu/math.c:228:51: warning: Using plain integer as NULL pointer
arch/powerpc/math-emu/math.c:237:13: warning: incorrect type in initializer (different address spaces)
arch/powerpc/math-emu/math.c:237:13:    expected unsigned int [noderef] __user *_gu_addr
arch/powerpc/math-emu/math.c:237:13:    got unsigned int [usertype] *
arch/powerpc/math-emu/math.c:226:1: warning: symbol 'do_mathemu' was not declared. Should it be static?

Add missing __user qualifier when casting pointer used in get_user()

Use NULL instead of 0 to initialise opX local variables.

Add a prototype for do_mathemu() (Added in processor.h like sparc)

Reported-by: kernel test robot <redacted>
Signed-off-by: Christophe Leroy <redacted>
---
 arch/powerpc/include/asm/processor.h | 2 ++
 arch/powerpc/kernel/traps.c          | 1 -
 arch/powerpc/math-emu/math.c         | 4 ++--
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 8acc3590c971..f21834a1d32e 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h

@@ -417,6 +417,8 @@ extern int fix_alignment(struct pt_regs *);
 #define NET_IP_ALIGN	0
 #endif
 
+int do_mathemu(struct pt_regs *regs);
+
 #endif /* __KERNEL__ */
 #endif /* __ASSEMBLY__ */
 #endif /* _ASM_POWERPC_PROCESSOR_H */

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index d615cd7ebfae..3cafbde7a51c 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c

@@ -1406,7 +1406,6 @@ int is_valid_bugaddr(unsigned long addr)
 static int emulate_math(struct pt_regs *regs)
 {
 	int ret;
-	extern int do_mathemu(struct pt_regs *regs);
 
 	ret = do_mathemu(regs);
 	if (ret >= 0)

diff --git a/arch/powerpc/math-emu/math.c b/arch/powerpc/math-emu/math.c
index 30b4b69c6941..327165f26ca6 100644
--- a/arch/powerpc/math-emu/math.c
+++ b/arch/powerpc/math-emu/math.c

@@ -225,7 +225,7 @@ record_exception(struct pt_regs *regs, int eflag)
 int
 do_mathemu(struct pt_regs *regs)
 {
-	void *op0 = 0, *op1 = 0, *op2 = 0, *op3 = 0;
+	void *op0 = NULL, *op1 = NULL, *op2 = NULL, *op3 = NULL;
 	unsigned long pc = regs->nip;
 	signed short sdisp;
 	u32 insn = 0;

@@ -234,7 +234,7 @@ do_mathemu(struct pt_regs *regs)
 	int type = 0;
 	int eflag, trap;
 
-	if (get_user(insn, (u32 *)pc))
+	if (get_user(insn, (u32 __user *)pc))
 		return -EFAULT;
 
 	switch (insn >> 26) {

-- 
2.25.0

On Mon, 15 Mar 2021 12:00:09 +0000 (UTC), Christophe Leroy wrote:

Sparse reports the following problems:

arch/powerpc/math-emu/math.c:228:21: warning: Using plain integer as NULL pointer
arch/powerpc/math-emu/math.c:228:31: warning: Using plain integer as NULL pointer
arch/powerpc/math-emu/math.c:228:41: warning: Using plain integer as NULL pointer
arch/powerpc/math-emu/math.c:228:51: warning: Using plain integer as NULL pointer
arch/powerpc/math-emu/math.c:237:13: warning: incorrect type in initializer (different address spaces)
arch/powerpc/math-emu/math.c:237:13:    expected unsigned int [noderef] __user *_gu_addr
arch/powerpc/math-emu/math.c:237:13:    got unsigned int [usertype] *
arch/powerpc/math-emu/math.c:226:1: warning: symbol 'do_mathemu' was not declared. Should it be static?

[...]

Applied to powerpc/next.

[1/1] powerpc/math: Fix missing __user qualifier for get_user() and other sparse warnings
      https://git.kernel.org/powerpc/c/e448e1e774dc0ca307c17e961daf7ede2e635c57

cheers