AMD General Reviewed-by: Hawking Zhang <[email protected]>
Regards, Hawking -----Original Message----- From: amd-gfx <[email protected]> On Behalf Of Shiwu Zhang Sent: Thursday, May 28, 2026 3:10 PM To: [email protected] Subject: [PATCH] drm/amdgpu: block the register writing if security lockdown In case of security lockdown with integrity, prevent the root from changing kernel/firmware state by register writing to comply with the LSM security requirement. Signed-off-by: Shiwu Zhang <[email protected]> --- drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c index 0ce6e2e4342c..3f9e5020722e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c @@ -27,6 +27,7 @@ #include <linux/pci.h> #include <linux/uaccess.h> #include <linux/pm_runtime.h> +#include <linux/security.h> #include "amdgpu.h" #include "amdgpu_pm.h" @@ -200,6 +201,9 @@ static ssize_t amdgpu_debugfs_regs_read(struct file *f, char __user *buf, static ssize_t amdgpu_debugfs_regs_write(struct file *f, const char __user *buf, size_t size, loff_t *pos) { + if (security_locked_down(LOCKDOWN_DEBUGFS)) + return -EPERM; + return amdgpu_debugfs_process_reg_op(false, f, (char __user *)buf, size, pos); } @@ -365,6 +369,9 @@ static ssize_t amdgpu_debugfs_regs2_read(struct file *f, char __user *buf, size_ static ssize_t amdgpu_debugfs_regs2_write(struct file *f, const char __user *buf, size_t size, loff_t *pos) { + if (security_locked_down(LOCKDOWN_DEBUGFS)) + return -EPERM; + return amdgpu_debugfs_regs2_op(f, (char __user *)buf, *pos, size, 1); } @@ -577,6 +584,9 @@ static ssize_t amdgpu_debugfs_regs_pcie_write(struct file *f, const char __user ssize_t result = 0; int r; + if (security_locked_down(LOCKDOWN_DEBUGFS)) + return -EPERM; + if (size & 0x3 || *pos & 0x3) return -EINVAL; @@ -684,6 +694,9 @@ static ssize_t amdgpu_debugfs_regs_pcie64_write(struct file *f, const char __use ssize_t result = 0; int r; + if (security_locked_down(LOCKDOWN_DEBUGFS)) + return -EPERM; + if (size & 0x7 || *pos & 0x7) return -EINVAL; @@ -798,6 +811,9 @@ static ssize_t amdgpu_debugfs_regs_didt_write(struct file *f, const char __user ssize_t result = 0; int r; + if (security_locked_down(LOCKDOWN_DEBUGFS)) + return -EPERM; + if (size & 0x3 || *pos & 0x3) return -EINVAL; @@ -915,6 +931,9 @@ static ssize_t amdgpu_debugfs_regs_smc_write(struct file *f, const char __user * ssize_t result = 0; int r; + if (security_locked_down(LOCKDOWN_DEBUGFS)) + return -EPERM; + if (!adev->reg.smc.wreg) return -EOPNOTSUPP; -- 2.43.0
