From fe3bdd12315656347d1bca82d920b3df1a2b0e8a Mon Sep 17 00:00:00 2001 From: Abdulla Anam Date: Wed, 22 Mar 2017 14:00:10 +0530 Subject: msm: vidc: Protect debug_buffer access in info_read with lock Serialize core_info_read & inst_info_read with lock so that multiple concurrent threads do not cause the write to overflow. Also have the bound check to avoid overflow in write_str function.. Change-Id: Ia18a4b94cafd69af1d367861f2499fc202f18e9f Signed-off-by: Abdulla Anam --- drivers/media/platform/msm/vidc/msm_v4l2_vidc.c | 3 +++ drivers/media/platform/msm/vidc/msm_vidc_debug.c | 33 +++++++++++++++++++++--- drivers/media/platform/msm/vidc/msm_vidc_debug.h | 1 + 3 files changed, 33 insertions(+), 4 deletions(-) diff --git a/drivers/media/platform/msm/vidc/msm_v4l2_vidc.c b/drivers/media/platform/msm/vidc/msm_v4l2_vidc.c index a632797..a8dc1d0 100644 --- a/drivers/media/platform/msm/vidc/msm_v4l2_vidc.c +++ b/drivers/media/platform/msm/vidc/msm_v4l2_vidc.c @@ -766,6 +766,8 @@ static int __init msm_vidc_init(void) if (rc) { dprintk(VIDC_ERR, "Failed to register platform driver\n"); + msm_vidc_debugfs_deinit_drv(); + debugfs_remove_recursive(vidc_driver->debugfs_root); kfree(vidc_driver); vidc_driver = NULL; } @@ -776,6 +778,7 @@ static int __init msm_vidc_init(void) static void __exit msm_vidc_exit(void) { platform_driver_unregister(&msm_vidc_driver); + msm_vidc_debugfs_deinit_drv(); debugfs_remove_recursive(vidc_driver->debugfs_root); mutex_destroy(&vidc_driver->lock); kfree(vidc_driver); diff --git a/drivers/media/platform/msm/vidc/msm_vidc_debug.c b/drivers/media/platform/msm/vidc/msm_vidc_debug.c index 1248a1c..a9b367d 100644 --- a/drivers/media/platform/msm/vidc/msm_vidc_debug.c +++ b/drivers/media/platform/msm/vidc/msm_vidc_debug.c @@ -38,6 +38,7 @@ bool msm_vidc_debug_timeout = false; #define MAX_DBG_BUF_SIZE 4096 struct debug_buffer { + struct mutex lock; char ptr[MAX_DBG_BUF_SIZE]; char *curr; u32 filled_size; @@ -64,8 +65,12 @@ static u32 write_str(struct debug_buffer *buffer, const char *fmt, ...) { va_list args; u32 size; + + char *curr = buffer->curr; + char *end = buffer->ptr + MAX_DBG_BUF_SIZE; + va_start(args, fmt); - size = vscnprintf(buffer->curr, MAX_DBG_BUF_SIZE - 1, fmt, args); + size = vscnprintf(curr, end - curr, fmt, args); va_end(args); buffer->curr += size; buffer->filled_size += size; @@ -79,12 +84,15 @@ static ssize_t core_info_read(struct file *file, char __user *buf, struct hfi_device *hdev; struct hal_fw_info fw_info = { {0} }; int i = 0, rc = 0; + ssize_t len = 0; if (!core || !core->device) { dprintk(VIDC_ERR, "Invalid params, core: %pK\n", core); return 0; } hdev = core->device; + + mutex_lock(&dbg_buf.lock); INIT_DBG_BUF(dbg_buf); write_str(&dbg_buf, "===============================\n"); write_str(&dbg_buf, "CORE %d: %pK\n", core->id, core); @@ -108,8 +116,11 @@ err_fw_info: completion_done(&core->completions[SYS_MSG_INDEX(i)]) ? "pending" : "done"); } - return simple_read_from_buffer(buf, count, ppos, + len = simple_read_from_buffer(buf, count, ppos, dbg_buf.ptr, dbg_buf.filled_size); + + mutex_unlock(&dbg_buf.lock); + return len; } static const struct file_operations core_info_fops = { @@ -147,7 +158,10 @@ static const struct file_operations ssr_fops = { struct dentry *msm_vidc_debugfs_init_drv(void) { bool ok = false; - struct dentry *dir = debugfs_create_dir("msm_vidc", NULL); + struct dentry *dir = NULL; + + mutex_init(&dbg_buf.lock); + dir = debugfs_create_dir("msm_vidc", NULL); if (IS_ERR_OR_NULL(dir)) { dir = NULL; goto failed_create_dir; @@ -216,6 +230,7 @@ struct dentry *msm_vidc_debugfs_init_core(struct msm_vidc_core *core, dprintk(VIDC_ERR, "Failed to create debugfs for msm_vidc\n"); goto failed_create_dir; } + if (!debugfs_create_file("info", S_IRUGO, dir, core, &core_info_fops)) { dprintk(VIDC_ERR, "debugfs_create_file: fail\n"); goto failed_create_dir; @@ -269,11 +284,14 @@ static ssize_t inst_info_read(struct file *file, char __user *buf, { struct msm_vidc_inst *inst = file->private_data; int i, j; + ssize_t len = 0; if (!inst) { dprintk(VIDC_ERR, "Invalid params, inst %pK\n", inst); return 0; } + + mutex_lock(&dbg_buf.lock); INIT_DBG_BUF(dbg_buf); write_str(&dbg_buf, "===============================\n"); write_str(&dbg_buf, "INSTANCE: %pK (%s)\n", inst, @@ -331,8 +349,10 @@ static ssize_t inst_info_read(struct file *file, char __user *buf, publish_unreleased_reference(inst); - return simple_read_from_buffer(buf, count, ppos, + len = simple_read_from_buffer(buf, count, ppos, dbg_buf.ptr, dbg_buf.filled_size); + mutex_unlock(&dbg_buf.lock); + return len; } static const struct file_operations inst_info_fops = { @@ -413,3 +433,8 @@ void msm_vidc_debugfs_update(struct msm_vidc_inst *inst, } } +void msm_vidc_debugfs_deinit_drv(void) +{ + mutex_destroy(&dbg_buf.lock); +} + diff --git a/drivers/media/platform/msm/vidc/msm_vidc_debug.h b/drivers/media/platform/msm/vidc/msm_vidc_debug.h index 39ac627..853ce4b 100644 --- a/drivers/media/platform/msm/vidc/msm_vidc_debug.h +++ b/drivers/media/platform/msm/vidc/msm_vidc_debug.h @@ -126,6 +126,7 @@ struct dentry *msm_vidc_debugfs_init_inst(struct msm_vidc_inst *inst, struct dentry *parent); void msm_vidc_debugfs_update(struct msm_vidc_inst *inst, enum msm_vidc_debugfs_event e); +void msm_vidc_debugfs_deinit_drv(void); static inline void tic(struct msm_vidc_inst *i, enum profiling_points p, char *b) -- cgit v1.1