diff options
| -rwxr-xr-x | arch/x86/include/asm/cpu_debug.h | 16 | ||||
| -rwxr-xr-x | arch/x86/kernel/cpu/cpu_debug.c | 118 |
2 files changed, 97 insertions, 37 deletions
diff --git a/arch/x86/include/asm/cpu_debug.h b/arch/x86/include/asm/cpu_debug.h index d24d64fcee0..56f1635e461 100755 --- a/arch/x86/include/asm/cpu_debug.h +++ b/arch/x86/include/asm/cpu_debug.h @@ -171,16 +171,22 @@ struct cpu_private { struct cpu_debug_base { char *name; /* Register name */ unsigned flag; /* Register flag */ + unsigned write; /* Register write flag */ }; -struct cpu_cpuX_base { - struct dentry *dentry; /* Register dentry */ - int init; /* Register index file */ -}; - +/* + * Currently it looks similar to cpu_debug_base but once we add more files + * cpu_file_base will go in different direction + */ struct cpu_file_base { char *name; /* Register file name */ unsigned flag; /* Register file flag */ + unsigned write; /* Register write flag */ +}; + +struct cpu_cpuX_base { + struct dentry *dentry; /* Register dentry */ + int init; /* Register index file */ }; struct cpu_debug_range { diff --git a/arch/x86/kernel/cpu/cpu_debug.c b/arch/x86/kernel/cpu/cpu_debug.c index 9abbcbd933c..21c0cf8ced1 100755 --- a/arch/x86/kernel/cpu/cpu_debug.c +++ b/arch/x86/kernel/cpu/cpu_debug.c @@ -11,6 +11,7 @@ #include <linux/seq_file.h> #include <linux/debugfs.h> #include <linux/kprobes.h> +#include <linux/uaccess.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/percpu.h> @@ -40,41 +41,41 @@ static DEFINE_MUTEX(cpu_debug_lock); static struct dentry *cpu_debugfs_dir; static struct cpu_debug_base cpu_base[] = { - { "mc", CPU_MC }, /* Machine Check */ - { "monitor", CPU_MONITOR }, /* Monitor */ - { "time", CPU_TIME }, /* Time */ - { "pmc", CPU_PMC }, /* Performance Monitor */ - { "platform", CPU_PLATFORM }, /* Platform */ - { "apic", CPU_APIC }, /* APIC */ - { "poweron", CPU_POWERON }, /* Power-on */ - { "control", CPU_CONTROL }, /* Control */ - { "features", CPU_FEATURES }, /* Features control */ - { "lastbranch", CPU_LBRANCH }, /* Last Branch */ - { "bios", CPU_BIOS }, /* BIOS */ - { "freq", CPU_FREQ }, /* Frequency */ - { "mtrr", CPU_MTRR }, /* MTRR */ - { "perf", CPU_PERF }, /* Performance */ - { "cache", CPU_CACHE }, /* Cache */ - { "sysenter", CPU_SYSENTER }, /* Sysenter */ - { "therm", CPU_THERM }, /* Thermal */ - { "misc", CPU_MISC }, /* Miscellaneous */ - { "debug", CPU_DEBUG }, /* Debug */ - { "pat", CPU_PAT }, /* PAT */ - { "vmx", CPU_VMX }, /* VMX */ - { "call", CPU_CALL }, /* System Call */ - { "base", CPU_BASE }, /* BASE Address */ - { "smm", CPU_SMM }, /* System mgmt mode */ - { "svm", CPU_SVM }, /*Secure Virtial Machine*/ - { "osvm", CPU_OSVM }, /* OS-Visible Workaround*/ - { "tss", CPU_TSS }, /* Task Stack Segment */ - { "cr", CPU_CR }, /* Control Registers */ - { "dt", CPU_DT }, /* Descriptor Table */ - { "registers", CPU_REG_ALL }, /* Select all Registers */ + { "mc", CPU_MC, 0 }, + { "monitor", CPU_MONITOR, 0 }, + { "time", CPU_TIME, 0 }, + { "pmc", CPU_PMC, 1 }, + { "platform", CPU_PLATFORM, 0 }, + { "apic", CPU_APIC, 0 }, + { "poweron", CPU_POWERON, 0 }, + { "control", CPU_CONTROL, 0 }, + { "features", CPU_FEATURES, 0 }, + { "lastbranch", CPU_LBRANCH, 0 }, + { "bios", CPU_BIOS, 0 }, + { "freq", CPU_FREQ, 0 }, + { "mtrr", CPU_MTRR, 0 }, + { "perf", CPU_PERF, 0 }, + { "cache", CPU_CACHE, 0 }, + { "sysenter", CPU_SYSENTER, 0 }, + { "therm", CPU_THERM, 0 }, + { "misc", CPU_MISC, 0 }, + { "debug", CPU_DEBUG, 0 }, + { "pat", CPU_PAT, 0 }, + { "vmx", CPU_VMX, 0 }, + { "call", CPU_CALL, 0 }, + { "base", CPU_BASE, 0 }, + { "smm", CPU_SMM, 0 }, + { "svm", CPU_SVM, 0 }, + { "osvm", CPU_OSVM, 0 }, + { "tss", CPU_TSS, 0 }, + { "cr", CPU_CR, 0 }, + { "dt", CPU_DT, 0 }, + { "registers", CPU_REG_ALL, 0 }, }; static struct cpu_file_base cpu_file[] = { - { "index", CPU_REG_ALL }, /* index */ - { "value", CPU_REG_ALL }, /* value */ + { "index", CPU_REG_ALL, 0 }, + { "value", CPU_REG_ALL, 1 }, }; /* Intel Registers Range */ @@ -608,9 +609,62 @@ static int cpu_seq_open(struct inode *inode, struct file *file) return err; } +static int write_msr(struct cpu_private *priv, u64 val) +{ + u32 low, high; + + high = (val >> 32) & 0xffffffff; + low = val & 0xffffffff; + + if (!wrmsr_safe_on_cpu(priv->cpu, priv->reg, low, high)) + return 0; + + return -EPERM; +} + +static int write_cpu_register(struct cpu_private *priv, const char *buf) +{ + int ret = -EPERM; + u64 val; + + ret = strict_strtoull(buf, 0, &val); + if (ret < 0) + return ret; + + /* Supporting only MSRs */ + if (priv->type < CPU_TSS_BIT) + return write_msr(priv, val); + + return ret; +} + +static ssize_t cpu_write(struct file *file, const char __user *ubuf, + size_t count, loff_t *off) +{ + struct seq_file *seq = file->private_data; + struct cpu_private *priv = seq->private; + char buf[19]; + + if ((priv == NULL) || (count >= sizeof(buf))) + return -EINVAL; + + if (copy_from_user(&buf, ubuf, count)) + return -EFAULT; + + buf[count] = 0; + + if ((cpu_base[priv->type].write) && (cpu_file[priv->file].write)) + if (!write_cpu_register(priv, buf)) + return count; + + return -EACCES; +} + static const struct file_operations cpu_fops = { + .owner = THIS_MODULE, .open = cpu_seq_open, .read = seq_read, + .write = cpu_write, .llseek = seq_lseek, .release = seq_release, }; |