[RFC PATCH v1 03/19] powerpc/ptrace: Consolidate reg index calculation
From: Christophe Leroy <hidden>
Date: 2020-08-12 12:07:39
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), ptrace support, the rest · Maintainers:
Madhavan Srinivasan, Oleg Nesterov, Linus Torvalds
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 <redacted> --- arch/powerpc/kernel/ptrace/ptrace.c | 20 ++++---------------- 1 file changed, 4 insertions(+), 16 deletions(-)
diff --git a/arch/powerpc/kernel/ptrace/ptrace.c b/arch/powerpc/kernel/ptrace/ptrace.c
index f6e51be47c6e..0b4645a7a1b4 100644
--- a/arch/powerpc/kernel/ptrace/ptrace.c
+++ b/arch/powerpc/kernel/ptrace/ptrace.c@@ -55,14 +55,8 @@ 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) - || (child->thread.regs == NULL)) -#else - index = addr >> 3; - if ((addr & 7) || (index > PT_FPSCR)) -#endif + index = addr / sizeof(long); + if ((addr & (sizeof(long) - 1)) || (index > PT_FPSCR) || !child->thread.regs) break; CHECK_FULL_REGS(child->thread.regs);
@@ -90,14 +84,8 @@ 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) - || (child->thread.regs == NULL)) -#else - index = addr >> 3; - if ((addr & 7) || (index > PT_FPSCR)) -#endif + index = addr / sizeof(long); + if ((addr & (sizeof(long) - 1)) || (index > PT_FPSCR) || !child->thread.regs) break; CHECK_FULL_REGS(child->thread.regs);
--
2.25.0