From e009fa433542cd09d6279e361b767a1f44ffd29a Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Tue, 18 Aug 2020 17:19:15 +0000 Subject: powerpc/ptrace: Consolidate reg index calculation Today we have: #ifdef CONFIG_PPC32 index = addr >> 2; if ((addr & 3) || child->thread.regs == NULL) #else index = addr >> 3; if ((addr & 7)) #endif sizeof(long) has value 4 for PPC32 and value 8 for PPC64. Dividing by 4 is equivalent to >> 2 and dividing by 8 is equivalent to >> 3. And 3 and 7 are respectively (sizeof(long) - 1). Use sizeof(long) to get rid of the #ifdef CONFIG_PPC32 and consolidate the calculation and checking. thread.regs have to be not NULL on both PPC32 and PPC64 so adding that test on PPC64 is harmless. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/3cd1e284e93c60db981659585e18d1f6bb73ed2f.1597770847.git.christophe.leroy@csgroup.eu --- arch/powerpc/kernel/ptrace/ptrace.c | 18 ++++-------------- 1 file changed, 4 insertions(+), 14 deletions(-) (limited to 'arch/powerpc') diff --git a/arch/powerpc/kernel/ptrace/ptrace.c b/arch/powerpc/kernel/ptrace/ptrace.c index f6e51be47c6e..51557a9c0765 100644 --- a/arch/powerpc/kernel/ptrace/ptrace.c +++ b/arch/powerpc/kernel/ptrace/ptrace.c @@ -55,14 +55,9 @@ long arch_ptrace(struct task_struct *child, long request, ret = -EIO; /* convert to index and check */ -#ifdef CONFIG_PPC32 - index = addr >> 2; - if ((addr & 3) || (index > PT_FPSCR) + index = addr / sizeof(long); + if ((addr & (sizeof(long) - 1)) || (index > PT_FPSCR) || (child->thread.regs == NULL)) -#else - index = addr >> 3; - if ((addr & 7) || (index > PT_FPSCR)) -#endif break; CHECK_FULL_REGS(child->thread.regs); @@ -90,14 +85,9 @@ long arch_ptrace(struct task_struct *child, long request, ret = -EIO; /* convert to index and check */ -#ifdef CONFIG_PPC32 - index = addr >> 2; - if ((addr & 3) || (index > PT_FPSCR) + index = addr / sizeof(long); + if ((addr & (sizeof(long) - 1)) || (index > PT_FPSCR) || (child->thread.regs == NULL)) -#else - index = addr >> 3; - if ((addr & 7) || (index > PT_FPSCR)) -#endif break; CHECK_FULL_REGS(child->thread.regs); -- cgit v1.2.3