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Commit 726e817a authored by Edgar Flores's avatar Edgar Flores
Browse files

msm: adsprpc: detect privileged processes based on group ID 



Detect if the process is privileged by comparing its group ID with
an internal list obtained from the device-tree. Update the process
attributes sent to the remote subsystem accordingly.

Change-Id: I8d7b6824762b934ca6bd9a5d2420dc0dd49b7e6d
Acked-by: default avatarThyagarajan Venkatanarayanan <venkatan@qti.qualcomm.com>
Signed-off-by: default avatarEdgar Flores <edgarf@codeaurora.org>
parent 43ee8667

drivers/char/adsprpc.c

+122 −1
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
#include <linux/cma.h>

#include <linux/iommu.h>

#include <linux/sort.h>

#include <linux/cred.h>

#include <linux/msm_dma_iommu_mapping.h>

#include "adsprpc_compat.h"

#include "adsprpc_shared.h"
@@ -135,6 +136,9 @@ 
#define INIT_MEMLEN_MAX  (8*1024*1024)

#define MAX_CACHE_BUF_SIZE (8*1024*1024)



/* Position of privilege bit in remote process attribute */

#define FASTRPC_MODE_PRIVILEGED		(1 << 6)



#define PERF_END (void)0



#define PERF(enb, cnt, ff) \
@@ -211,6 +215,11 @@ struct secure_vm { 
	int vmcount;

};



struct gid_list {

	unsigned int *gids;

	unsigned int gidcount;

};



struct fastrpc_file;



struct fastrpc_buf {
@@ -359,6 +368,7 @@ struct fastrpc_apps { 
	struct wakeup_source *wake_source_secure;

	/* Non-secure subsystem like CDSP will use regular client */

	struct wakeup_source *wake_source;

	struct gid_list gidlist;

};



struct fastrpc_mmap {
@@ -442,6 +452,7 @@ struct fastrpc_file { 
	char *debug_buf;

	/* Flag to enable PM wake/relax voting for every remote invoke */

	int wake_enable;

	struct gid_list gidlist;

};



static struct fastrpc_apps gfa;
@@ -1192,7 +1203,32 @@ static int context_restore_interrupted(struct fastrpc_file *fl, 
	return err;

}



static unsigned int sorted_lists_intersection(unsigned int *listA,

		unsigned int lenA, unsigned int *listB, unsigned int lenB)

{

	unsigned int i = 0, j = 0;



	while (i < lenA && j < lenB) {

		if (listA[i] < listB[j])

			i++;

		else if (listA[i] > listB[j])

			j++;

		else

			return listA[i];

	}

	return 0;

}



#define CMP(aa, bb) ((aa) == (bb) ? 0 : (aa) < (bb) ? -1 : 1)



static int uint_cmp_func(const void *p1, const void *p2)

{

	unsigned int a1 = *((unsigned int *)p1);

	unsigned int a2 = *((unsigned int *)p2);



	return CMP(a1, a2);

}



static int overlap_ptr_cmp(const void *a, const void *b)

{

	struct overlap *pa = *((struct overlap **)a);
@@ -2333,6 +2369,22 @@ static int fastrpc_get_spd_session(char *name, int *session, int *cid) 
static int fastrpc_mmap_remove_pdr(struct fastrpc_file *fl);

static int fastrpc_channel_open(struct fastrpc_file *fl);

static int fastrpc_mmap_remove_ssr(struct fastrpc_file *fl);



static void fastrpc_check_privileged_process(struct fastrpc_file *fl,

				struct fastrpc_ioctl_init_attrs *uproc)

{

	unsigned int gid = sorted_lists_intersection(fl->gidlist.gids,

		fl->gidlist.gidcount, gfa.gidlist.gids, gfa.gidlist.gidcount);



	/* disregard any privilege bits from userspace */

	uproc->attrs &= (~FASTRPC_MODE_PRIVILEGED);

	if (gid) {

		pr_info("adsprpc: %s: %s (PID %d, GID %u) is a privileged process\n",

				__func__, current->comm, fl->tgid, gid);

		uproc->attrs |= FASTRPC_MODE_PRIVILEGED;

	}

}



static int fastrpc_init_process(struct fastrpc_file *fl,

				struct fastrpc_ioctl_init_attrs *uproc)

{
@@ -2411,6 +2463,8 @@ static int fastrpc_init_process(struct fastrpc_file *fl, 
		}

		inbuf.pageslen = 1;



		fastrpc_check_privileged_process(fl, uproc);



		VERIFY(err, !init->mem);

		if (err) {

			err = -EINVAL;
@@ -3469,6 +3523,7 @@ static int fastrpc_file_free(struct fastrpc_file *fl) 
	hlist_del_init(&fl->hn);

	spin_unlock(&fl->apps->hlock);

	kfree(fl->debug_buf);

	kfree(fl->gidlist.gids);



	if (!fl->sctx) {

		kfree(fl);
@@ -3873,6 +3928,34 @@ static int fastrpc_device_open(struct inode *inode, struct file *filp) 
	return 0;

}



static int fastrpc_get_process_gids(struct gid_list *gidlist)

{

	struct group_info *group_info = get_current_groups();

	int i = 0, err = 0, num_gids = group_info->ngroups + 1;

	unsigned int *gids = NULL;



	gids = kcalloc(num_gids, sizeof(unsigned int), GFP_KERNEL);

	if (!gids) {

		err = -ENOMEM;

		goto bail;

	}



	/* Get the real GID */

	gids[0] = __kgid_val(current_gid());



	/* Get the supplemental GIDs */

	for (i = 1; i < num_gids; i++)

		gids[i] = __kgid_val(group_info->gid[i - 1]);



	sort(gids, num_gids, sizeof(*gids), uint_cmp_func, NULL);

	gidlist->gids = gids;

	gidlist->gidcount = num_gids;

bail:

	if (err)

		kfree(gids);

	return err;

}



static int fastrpc_get_info(struct fastrpc_file *fl, uint32_t *info)

{

	int err = 0;
@@ -3881,6 +3964,7 @@ static int fastrpc_get_info(struct fastrpc_file *fl, uint32_t *info) 
	VERIFY(err, fl != NULL);

	if (err)

		goto bail;

	fastrpc_get_process_gids(&fl->gidlist);

	if (fl->cid == -1) {

		cid = *info;

		VERIFY(err, cid < NUM_CHANNELS);
@@ -4555,6 +4639,41 @@ static void init_secure_vmid_list(struct device *dev, char *prop_name, 
	}

}



static void fastrpc_init_privileged_gids(struct device *dev, char *prop_name,

						struct gid_list *gidlist)

{

	int err = 0;

	u32 len = 0, i = 0;

	u32 *gids = NULL;



	if (!of_find_property(dev->of_node, prop_name, &len))

		goto bail;

	if (len == 0)

		goto bail;

	len /= sizeof(u32);

	gids = kcalloc(len, sizeof(u32), GFP_KERNEL);

	if (!gids) {

		err = ENOMEM;

		goto bail;

	}

	for (i = 0; i < len; i++) {

		err = of_property_read_u32_index(dev->of_node, prop_name,

								i, &gids[i]);

		if (err) {

			pr_err("Error: adsprpc: %s: failed to read GID %u\n",

					__func__, i);

			goto bail;

		}

		pr_info("adsprpc: %s: privileged GID: %u\n", __func__, gids[i]);

	}

	sort(gids, len, sizeof(*gids), uint_cmp_func, NULL);

	gidlist->gids = gids;

	gidlist->gidcount = len;

bail:

	if (err)

		kfree(gids);

}



static void configure_secure_channels(uint32_t secure_domains)

{

	struct fastrpc_apps *me = &gfa;
@@ -4587,7 +4706,8 @@ static int fastrpc_probe(struct platform_device *pdev) 
					"qcom,msm-fastrpc-compute")) {

		init_secure_vmid_list(dev, "qcom,adsp-remoteheap-vmid",

							&gcinfo[0].rhvm);



		fastrpc_init_privileged_gids(dev, "qcom,fastrpc-gids",

					&me->gidlist);



		of_property_read_u32(dev->of_node, "qcom,rpc-latency-us",

			&me->latency);
@@ -4884,6 +5004,7 @@ static void __exit fastrpc_device_exit(void) 
		wakeup_source_unregister(me->wake_source);

	if (me->wake_source_secure)

		wakeup_source_unregister(me->wake_source_secure);

	kfree(me->gidlist.gids);

	debugfs_remove_recursive(debugfs_root);

}