Patchwork [v6,4/5] powerpc/kgdb: use DEFINE_PER_CPU to allocate kgdb's thread_info

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Submitter Tiejun Chen
Date Oct. 23, 2013, 9:31 a.m.
Message ID <1382520685-11609-5-git-send-email-tiejun.chen@windriver.com>
Download mbox | patch
Permalink /patch/285592/
State Superseded
Delegated to: Scott Wood
Headers show

Comments

Tiejun Chen - Oct. 23, 2013, 9:31 a.m.
Use DEFINE_PER_CPU to allocate thread_info statically instead of kmalloc().
This can avoid introducing more memory check codes.

Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
---
 arch/powerpc/kernel/kgdb.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

Patch

diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
index c1eef24..447c14b 100644
--- a/arch/powerpc/kernel/kgdb.c
+++ b/arch/powerpc/kernel/kgdb.c
@@ -151,15 +151,15 @@  static int kgdb_handle_breakpoint(struct pt_regs *regs)
 	return 1;
 }
 
+static DEFINE_PER_CPU(struct thread_info, kgdb_thread_info);
 static int kgdb_singlestep(struct pt_regs *regs)
 {
 	struct thread_info *thread_info, *exception_thread_info;
-	struct thread_info *backup_current_thread_info;
+	struct thread_info *backup_current_thread_info = &__get_cpu_var(kgdb_thread_info);
 
 	if (user_mode(regs))
 		return 0;
 
-	backup_current_thread_info = kmalloc(sizeof(struct thread_info), GFP_KERNEL);
 	/*
 	 * On Book E and perhaps other processors, singlestep is handled on
 	 * the critical exception stack.  This causes current_thread_info()
@@ -185,7 +185,6 @@  static int kgdb_singlestep(struct pt_regs *regs)
 		/* Restore current_thread_info lastly. */
 		memcpy(exception_thread_info, backup_current_thread_info, sizeof *thread_info);
 
-	kfree(backup_current_thread_info);
 	return 1;
 }