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Commit 1227daa4 authored by Kees Cook's avatar Kees Cook
Browse files

pstore/ram: Clarify resource reservation labels 



When ramoops reserved a memory region in the kernel, it had an unhelpful
label of "persistent_memory". When reading /proc/iomem, it would be
repeated many times, did not hint that it was ramoops in particular,
and didn't clarify very much about what each was used for:

400000000-407ffffff : Persistent Memory (legacy)
  400000000-400000fff : persistent_memory
  400001000-400001fff : persistent_memory
...
  4000ff000-4000fffff : persistent_memory

Instead, this adds meaningful labels for how the various regions are
being used:

400000000-407ffffff : Persistent Memory (legacy)
  400000000-400000fff : ramoops:dump(0/252)
  400001000-400001fff : ramoops:dump(1/252)
...
  4000fc000-4000fcfff : ramoops:dump(252/252)
  4000fd000-4000fdfff : ramoops:console
  4000fe000-4000fe3ff : ramoops:ftrace(0/3)
  4000fe400-4000fe7ff : ramoops:ftrace(1/3)
  4000fe800-4000febff : ramoops:ftrace(2/3)
  4000fec00-4000fefff : ramoops:ftrace(3/3)
  4000ff000-4000fffff : ramoops:pmsg

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatarJoel Fernandes (Google) <joel@joelfernandes.org>
Tested-by: default avatarSai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Tested-by: default avatarGuenter Roeck <groeck@chromium.org>
parent 95047b05

fs/pstore/ram.c

+13 −3
Original line number Diff line number Diff line
@@ -587,9 +587,16 @@ static int ramoops_init_przs(const char *name, 
		goto fail;



	for (i = 0; i < *cnt; i++) {

		char *label;



		if (*cnt == 1)

			label = kasprintf(GFP_KERNEL, "ramoops:%s", name);

		else

			label = kasprintf(GFP_KERNEL, "ramoops:%s(%d/%d)",

					  name, i, *cnt - 1);

		prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,

					       &cxt->ecc_info,

						  cxt->memtype, flags);

					       cxt->memtype, flags, label);

		if (IS_ERR(prz_ar[i])) {

			err = PTR_ERR(prz_ar[i]);

			dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
@@ -619,6 +626,8 @@ static int ramoops_init_prz(const char *name, 
			    struct persistent_ram_zone **prz,

			    phys_addr_t *paddr, size_t sz, u32 sig)

{

	char *label;



	if (!sz)

		return 0;
@@ -629,8 +638,9 @@ static int ramoops_init_prz(const char *name, 
		return -ENOMEM;

	}



	label = kasprintf(GFP_KERNEL, "ramoops:%s", name);

	*prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,

				  cxt->memtype, 0);

				  cxt->memtype, 0, label);

	if (IS_ERR(*prz)) {

		int err = PTR_ERR(*prz);

fs/pstore/ram_core.c

+7 −4
Original line number Diff line number Diff line
@@ -433,11 +433,11 @@ static void *persistent_ram_vmap(phys_addr_t start, size_t size, 
}



static void *persistent_ram_iomap(phys_addr_t start, size_t size,

		unsigned int memtype)

		unsigned int memtype, char *label)

{

	void *va;



	if (!request_mem_region(start, size, "persistent_ram")) {

	if (!request_mem_region(start, size, label ?: "ramoops")) {

		pr_err("request mem region (0x%llx@0x%llx) failed\n",

			(unsigned long long)size, (unsigned long long)start);

		return NULL;
@@ -460,7 +460,8 @@ static int persistent_ram_buffer_map(phys_addr_t start, phys_addr_t size, 
	if (pfn_valid(start >> PAGE_SHIFT))

		prz->vaddr = persistent_ram_vmap(start, size, memtype);

	else

		prz->vaddr = persistent_ram_iomap(start, size, memtype);

		prz->vaddr = persistent_ram_iomap(start, size, memtype,

						  prz->label);



	if (!prz->vaddr) {

		pr_err("%s: Failed to map 0x%llx pages at 0x%llx\n", __func__,
@@ -530,12 +531,13 @@ void persistent_ram_free(struct persistent_ram_zone *prz) 
	prz->ecc_info.par = NULL;



	persistent_ram_free_old(prz);

	kfree(prz->label);

	kfree(prz);

}



struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,

			u32 sig, struct persistent_ram_ecc_info *ecc_info,

			unsigned int memtype, u32 flags)

			unsigned int memtype, u32 flags, char *label)

{

	struct persistent_ram_zone *prz;

	int ret = -ENOMEM;
@@ -549,6 +551,7 @@ struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size, 
	/* Initialize general buffer state. */

	raw_spin_lock_init(&prz->buffer_lock);

	prz->flags = flags;

	prz->label = label;



	ret = persistent_ram_buffer_map(start, size, prz, memtype);

	if (ret)

include/linux/pstore_ram.h

+2 −1
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ struct persistent_ram_zone { 
	phys_addr_t paddr;

	size_t size;

	void *vaddr;

	char *label;

	struct persistent_ram_buffer *buffer;

	size_t buffer_size;

	u32 flags;
@@ -65,7 +66,7 @@ struct persistent_ram_zone { 


struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,

			u32 sig, struct persistent_ram_ecc_info *ecc_info,

			unsigned int memtype, u32 flags);

			unsigned int memtype, u32 flags, char *label);

void persistent_ram_free(struct persistent_ram_zone *prz);

void persistent_ram_zap(struct persistent_ram_zone *prz);