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Message-ID: <20180620182647.GA24405@beast>
Date: Wed, 20 Jun 2018 11:26:47 -0700
From: Kees Cook <keescook@...omium.org>
To: Alex Deucher <alexander.deucher@....com>
Cc: linux-kernel@...r.kernel.org,
Christian König <christian.koenig@....com>,
"David (ChunMing) Zhou" <David1.Zhou@....com>,
David Airlie <airlied@...ux.ie>, Rex Zhu <Rex.Zhu@....com>,
Huang Rui <ray.huang@....com>,
Felix Kuehling <Felix.Kuehling@....com>,
amd-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org
Subject: [PATCH] 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
Signed-off-by: Kees Cook <keescook@...omium.org>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c | 100 +++++++++++--------------
1 file changed, 42 insertions(+), 58 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
index b455da487782..5eb98cde22ed 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
@@ -593,40 +593,59 @@ static ssize_t amdgpu_get_pp_dpm_sclk(struct device *dev,
return snprintf(buf, PAGE_SIZE, "\n");
}
-static ssize_t amdgpu_set_pp_dpm_sclk(struct device *dev,
- struct device_attribute *attr,
- const char *buf,
- size_t count)
+/*
+ * 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)
{
- 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];
+ char buf_cpy[AMDGPU_MASK_BUF_MAX + 1];
const char delimiter[3] = {' ', '\n', '\0'};
+ size_t bytes;
- memcpy(buf_cpy, buf, count+1);
+ *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);
+ sub_str = strsep(&tmp, delimiter);
if (strlen(sub_str)) {
ret = kstrtol(sub_str, 0, &level);
-
- if (ret) {
- count = -EINVAL;
- goto fail;
- }
- mask |= 1 << 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,
+ size_t count)
+{
+ struct drm_device *ddev = dev_get_drvdata(dev);
+ struct amdgpu_device *adev = ddev->dev_private;
+ int ret;
+ uint32_t mask = 0;
+
+ ret = amdgpu_read_mask(buf, count, &mask);
+ if (ret)
+ return ret;
+
if (adev->powerplay.pp_funcs->force_clock_level)
amdgpu_dpm_force_clock_level(adev, PP_SCLK, mask);
-fail:
return count;
}
@@ -651,32 +670,15 @@ 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;
}
@@ -701,33 +703,15 @@ 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;
- 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_PCIE, mask);
-fail:
return count;
}
--
2.17.1
--
Kees Cook
Pixel Security
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