drm/amdgpu/pm: Remove VLA usage
In the quest to remove all stack VLA usage from the kernel[1], this
uses the maximum sane buffer size and removes copy/paste code.
[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com
Reviewed-by: Rex Zhu <rezhu@amd.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
index f1404ad..15a1192 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
@@ -606,6 +606,42 @@ static ssize_t amdgpu_get_pp_dpm_sclk(struct device *dev,
return snprintf(buf, PAGE_SIZE, "\n");
}
+/*
+ * Worst case: 32 bits individually specified, in octal at 12 characters
+ * per line (+1 for \n).
+ */
+#define AMDGPU_MASK_BUF_MAX (32 * 13)
+
+static ssize_t amdgpu_read_mask(const char *buf, size_t count, uint32_t *mask)
+{
+ int ret;
+ long level;
+ char *sub_str = NULL;
+ char *tmp;
+ char buf_cpy[AMDGPU_MASK_BUF_MAX + 1];
+ const char delimiter[3] = {' ', '\n', '\0'};
+ size_t bytes;
+
+ *mask = 0;
+
+ bytes = min(count, sizeof(buf_cpy) - 1);
+ memcpy(buf_cpy, buf, bytes);
+ buf_cpy[bytes] = '\0';
+ tmp = buf_cpy;
+ while (tmp[0]) {
+ sub_str = strsep(&tmp, delimiter);
+ if (strlen(sub_str)) {
+ ret = kstrtol(sub_str, 0, &level);
+ if (ret)
+ return -EINVAL;
+ *mask |= 1 << level;
+ } else
+ break;
+ }
+
+ return 0;
+}
+
static ssize_t amdgpu_set_pp_dpm_sclk(struct device *dev,
struct device_attribute *attr,
const char *buf,
@@ -614,32 +650,15 @@ static ssize_t amdgpu_set_pp_dpm_sclk(struct device *dev,
struct drm_device *ddev = dev_get_drvdata(dev);
struct amdgpu_device *adev = ddev->dev_private;
int ret;
- long level;
uint32_t mask = 0;
- char *sub_str = NULL;
- char *tmp;
- char buf_cpy[count];
- const char delimiter[3] = {' ', '\n', '\0'};
- memcpy(buf_cpy, buf, count+1);
- tmp = buf_cpy;
- while (tmp[0]) {
- sub_str = strsep(&tmp, delimiter);
- if (strlen(sub_str)) {
- ret = kstrtol(sub_str, 0, &level);
+ ret = amdgpu_read_mask(buf, count, &mask);
+ if (ret)
+ return ret;
- if (ret) {
- count = -EINVAL;
- goto fail;
- }
- mask |= 1 << level;
- } else
- break;
- }
if (adev->powerplay.pp_funcs->force_clock_level)
amdgpu_dpm_force_clock_level(adev, PP_SCLK, mask);
-fail:
return count;
}
@@ -664,32 +683,15 @@ static ssize_t amdgpu_set_pp_dpm_mclk(struct device *dev,
struct drm_device *ddev = dev_get_drvdata(dev);
struct amdgpu_device *adev = ddev->dev_private;
int ret;
- long level;
uint32_t mask = 0;
- char *sub_str = NULL;
- char *tmp;
- char buf_cpy[count];
- const char delimiter[3] = {' ', '\n', '\0'};
- memcpy(buf_cpy, buf, count+1);
- tmp = buf_cpy;
- while (tmp[0]) {
- sub_str = strsep(&tmp, delimiter);
- if (strlen(sub_str)) {
- ret = kstrtol(sub_str, 0, &level);
+ ret = amdgpu_read_mask(buf, count, &mask);
+ if (ret)
+ return ret;
- if (ret) {
- count = -EINVAL;
- goto fail;
- }
- mask |= 1 << level;
- } else
- break;
- }
if (adev->powerplay.pp_funcs->force_clock_level)
amdgpu_dpm_force_clock_level(adev, PP_MCLK, mask);
-fail:
return count;
}
@@ -714,33 +716,15 @@ static ssize_t amdgpu_set_pp_dpm_pcie(struct device *dev,
struct drm_device *ddev = dev_get_drvdata(dev);
struct amdgpu_device *adev = ddev->dev_private;
int ret;
- long level;
uint32_t mask = 0;
- char *sub_str = NULL;
- char *tmp;
- char buf_cpy[count];
- const char delimiter[3] = {' ', '\n', '\0'};
- memcpy(buf_cpy, buf, count+1);
- tmp = buf_cpy;
+ ret = amdgpu_read_mask(buf, count, &mask);
+ if (ret)
+ return ret;
- while (tmp[0]) {
- sub_str = strsep(&tmp, delimiter);
- if (strlen(sub_str)) {
- ret = kstrtol(sub_str, 0, &level);
-
- if (ret) {
- count = -EINVAL;
- goto fail;
- }
- mask |= 1 << level;
- } else
- break;
- }
if (adev->powerplay.pp_funcs->force_clock_level)
amdgpu_dpm_force_clock_level(adev, PP_PCIE, mask);
-fail:
return count;
}