From: Andi Kleen Date: Sat, 16 Apr 2005 22:25:10 +0000 (-0700) Subject: [PATCH] x86_64: Remove excessive stack allocation in MCE code with large NR_CPUS X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=f0de53bbc2118c754ee923516122d91add288582;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git [PATCH] x86_64: Remove excessive stack allocation in MCE code with large NR_CPUS Remove excessive stack allocation in MCE code with large NR_CPUS Signed-off-by: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/x86_64/kernel/mce.c b/arch/x86_64/kernel/mce.c index 6ca066424dee..3a89d735a4f6 100644 --- a/arch/x86_64/kernel/mce.c +++ b/arch/x86_64/kernel/mce.c @@ -379,18 +379,23 @@ static void collect_tscs(void *data) static ssize_t mce_read(struct file *filp, char __user *ubuf, size_t usize, loff_t *off) { - unsigned long cpu_tsc[NR_CPUS]; + unsigned long *cpu_tsc; static DECLARE_MUTEX(mce_read_sem); unsigned next; char __user *buf = ubuf; int i, err; + cpu_tsc = kmalloc(NR_CPUS * sizeof(long), GFP_KERNEL); + if (!cpu_tsc) + return -ENOMEM; + down(&mce_read_sem); next = rcu_dereference(mcelog.next); /* Only supports full reads right now */ if (*off != 0 || usize < MCE_LOG_LEN*sizeof(struct mce)) { up(&mce_read_sem); + kfree(cpu_tsc); return -EINVAL; } @@ -421,6 +426,7 @@ static ssize_t mce_read(struct file *filp, char __user *ubuf, size_t usize, loff } } up(&mce_read_sem); + kfree(cpu_tsc); return err ? -EFAULT : buf - ubuf; }