From 4338774cd41a6abf72aa76585ce2184cea8ff8a2 Mon Sep 17 00:00:00 2001 From: Dave Jones Date: Tue, 18 Jun 2013 12:09:11 -0400 Subject: x86/debug: Only print out DR registers if they are not power-on defaults The DR registers are rarely useful when decoding oopses. With screen real estate during oopses at a premium, we can save two lines by only printing out these registers when they are set to something other than they power-on state. Signed-off-by: Dave Jones Acked-by: Borislav Petkov Cc: Linus Torvalds Cc: Andrew Morton Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20130618160911.GA24487@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/process_32.c | 11 ++++++++--- arch/x86/kernel/process_64.c | 9 ++++++++- 2 files changed, 16 insertions(+), 4 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 7305f7dfc7ab..f84cfd1b0c0b 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -110,11 +110,16 @@ void __show_regs(struct pt_regs *regs, int all) get_debugreg(d1, 1); get_debugreg(d2, 2); get_debugreg(d3, 3); - printk(KERN_DEFAULT "DR0: %08lx DR1: %08lx DR2: %08lx DR3: %08lx\n", - d0, d1, d2, d3); - get_debugreg(d6, 6); get_debugreg(d7, 7); + + /* Only print out debug registers if they are in their non-default state. */ + if ((d0 == 0) && (d1 == 0) && (d2 == 0) && (d3 == 0) && + (d6 == DR6_RESERVED) && (d7 == 0x400)) + return; + + printk(KERN_DEFAULT "DR0: %08lx DR1: %08lx DR2: %08lx DR3: %08lx\n", + d0, d1, d2, d3); printk(KERN_DEFAULT "DR6: %08lx DR7: %08lx\n", d6, d7); } diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 355ae06dbf94..a8b9abc5459a 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -105,11 +105,18 @@ void __show_regs(struct pt_regs *regs, int all) get_debugreg(d0, 0); get_debugreg(d1, 1); get_debugreg(d2, 2); - printk(KERN_DEFAULT "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2); get_debugreg(d3, 3); get_debugreg(d6, 6); get_debugreg(d7, 7); + + /* Only print out debug registers if they are in their non-default state. */ + if ((d0 == 0) && (d1 == 0) && (d2 == 0) && (d3 == 0) && + (d6 == DR6_RESERVED) && (d7 == 0x400)) + return; + + printk(KERN_DEFAULT "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2); printk(KERN_DEFAULT "DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7); + } void release_thread(struct task_struct *dead_task) -- cgit v1.2.3 From 5a802e15308f152247433d87050d1bfbf9613483 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Sun, 16 Jun 2013 14:12:47 +0930 Subject: x86: Remove weird PTR_ERR() in do_debug 62edab905 changed the argument to notify_die() from dr6 to &dr6, but weirdly, used PTR_ERR() to cast it to a long. Since dr6 is on the stack, this is an abuse of PTR_ERR(). Cast to long, as per kernel standard. Signed-off-by: Rusty Russell Cc: K.Prasad Link: http://lkml.kernel.org/r/1371357768-4968-8-git-send-email-rusty@rustcorp.com.au Signed-off-by: Ingo Molnar --- arch/x86/kernel/traps.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86') diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 772e2a846dec..9340dfb7057f 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -437,7 +437,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) /* Store the virtualized DR6 value */ tsk->thread.debugreg6 = dr6; - if (notify_die(DIE_DEBUG, "debug", regs, PTR_ERR(&dr6), error_code, + if (notify_die(DIE_DEBUG, "debug", regs, (long)&dr6, error_code, SIGTRAP) == NOTIFY_STOP) goto exit; -- cgit v1.2.3 From 13bfd47a0ef68fc8b21e67873dbdf269c7db6b59 Mon Sep 17 00:00:00 2001 From: Qiaowei Ren Date: Mon, 24 Jun 2013 13:55:33 +0800 Subject: x86/tboot: Provide debugfs interfaces to access TXT log These logs come from tboot (Trusted Boot, an open source, pre-kernel/VMM module that uses Intel TXT to perform a measured and verified launch of an OS kernel/VMM.). Signed-off-by: Qiaowei Ren Acked-by: H. Peter Anvin Cc: Gang Wei Link: http://lkml.kernel.org/r/1372053333-21788-1-git-send-email-qiaowei.ren@intel.com [ Beautified the code a bit. ] Signed-off-by: Ingo Molnar --- arch/x86/kernel/tboot.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) (limited to 'arch/x86') diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c index f84fe00fad48..3ff42d2f046d 100644 --- a/arch/x86/kernel/tboot.c +++ b/arch/x86/kernel/tboot.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include @@ -338,6 +339,73 @@ static struct notifier_block tboot_cpu_notifier __cpuinitdata = .notifier_call = tboot_cpu_callback, }; +#ifdef CONFIG_DEBUG_FS + +#define TBOOT_LOG_UUID { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \ + 0x4c, 0x84, 0xa3, 0xe9, 0x53, 0xb8, 0x81, 0x74 } + +#define TBOOT_SERIAL_LOG_ADDR 0x60000 +#define TBOOT_SERIAL_LOG_SIZE 0x08000 +#define LOG_MAX_SIZE_OFF 16 +#define LOG_BUF_OFF 24 + +static uint8_t tboot_log_uuid[16] = TBOOT_LOG_UUID; + +static ssize_t tboot_log_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) +{ + void __iomem *log_base; + u8 log_uuid[16]; + u32 max_size; + void *kbuf; + int ret = -EFAULT; + + log_base = ioremap_nocache(TBOOT_SERIAL_LOG_ADDR, TBOOT_SERIAL_LOG_SIZE); + if (!log_base) + return ret; + + memcpy_fromio(log_uuid, log_base, sizeof(log_uuid)); + if (memcmp(&tboot_log_uuid, log_uuid, sizeof(log_uuid))) + goto err_iounmap; + + max_size = readl(log_base + LOG_MAX_SIZE_OFF); + if (*ppos >= max_size) { + ret = 0; + goto err_iounmap; + } + + if (*ppos + count > max_size) + count = max_size - *ppos; + + kbuf = kmalloc(count, GFP_KERNEL); + if (!kbuf) { + ret = -ENOMEM; + goto err_iounmap; + } + + memcpy_fromio(kbuf, log_base + LOG_BUF_OFF + *ppos, count); + if (copy_to_user(user_buf, kbuf, count)) + goto err_kfree; + + *ppos += count; + + ret = count; + +err_kfree: + kfree(kbuf); + +err_iounmap: + iounmap(log_base); + + return ret; +} + +static const struct file_operations tboot_log_fops = { + .read = tboot_log_read, + .llseek = default_llseek, +}; + +#endif /* CONFIG_DEBUG_FS */ + static __init int tboot_late_init(void) { if (!tboot_enabled()) @@ -348,6 +416,11 @@ static __init int tboot_late_init(void) atomic_set(&ap_wfs_count, 0); register_hotcpu_notifier(&tboot_cpu_notifier); +#ifdef CONFIG_DEBUG_FS + debugfs_create_file("tboot_log", S_IRUSR, + arch_debugfs_dir, NULL, &tboot_log_fops); +#endif + acpi_os_set_prepare_sleep(&tboot_sleep); return 0; } -- cgit v1.2.3