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| author |   Lv Zheng <lv.zheng@intel.com> | 2015-08-05 16:23:57 +0800 |
|---|---|---|
| committer |   Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-08-07 02:42:22 +0200 |
| commit | a0186bcf7c21907c78ab2b4bc50f3fb2b5047806 (patch) | |
| tree | 2826d7cbdddc8d61d4cf5660d5d9aee69b6dfe30 /drivers/acpi | |
| parent | ACPI / sysfs: Update method tracing facility. (diff) | |
| download | linux-dev-a0186bcf7c21907c78ab2b4bc50f3fb2b5047806.tar.xz linux-dev-a0186bcf7c21907c78ab2b4bc50f3fb2b5047806.zip | |
ACPI / sysfs: Add support to allow leading "\" missing in trace_method_name.
Since _SB.PCI0 can be used as relative path from root and can be easily
converted into internal trace_method_name format, we allow users to specify
trace_method_name using relative paths from root.
Note this is useful for grub2 for which users failed to pass "\" from the
grub configuration file.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/sysfs.c | 28 |
1 files changed, 13 insertions, 15 deletions
diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c index 8979e4a8d066..40a42655227c 100644 --- a/drivers/acpi/sysfs.c +++ b/drivers/acpi/sysfs.c @@ -164,14 +164,18 @@ static const struct kernel_param_ops param_ops_debug_level = { module_param_cb(debug_layer, ¶m_ops_debug_layer, &acpi_dbg_layer, 0644); module_param_cb(debug_level, ¶m_ops_debug_level, &acpi_dbg_level, 0644); -static char* trace_method_name; -static bool trace_method_kmalloced; +static char trace_method_name[1024]; int param_set_trace_method_name(const char *val, const struct kernel_param *kp) { u32 saved_flags = 0; + bool is_abs_path = true; - if (strlen(val) > 1024) { + if (*val != '\\') + is_abs_path = false; + + if ((is_abs_path && strlen(val) > 1023) || + (!is_abs_path && strlen(val) > 1022)) { pr_err("%s: string parameter too long\n", kp->name); return -ENOSPC; } @@ -187,19 +191,13 @@ int param_set_trace_method_name(const char *val, const struct kernel_param *kp) acpi_gbl_trace_dbg_layer, 0); - if (trace_method_kmalloced) - kfree(trace_method_name); - trace_method_name = NULL; - trace_method_kmalloced = false; - /* This is a hack. We can't kmalloc in early boot. */ - if (slab_is_available()) { - trace_method_name = kstrdup(val, GFP_KERNEL); - if (!trace_method_name) - return -ENOMEM; - trace_method_kmalloced = true; - } else - trace_method_name = (char *)val; + if (is_abs_path) + strcpy(trace_method_name, val); + else { + trace_method_name[0] = '\\'; + strcpy(trace_method_name+1, val); + } /* Restore the original tracer state */ (void)acpi_debug_trace(trace_method_name, |