From 1227daa43bce1318ff6fb54e6cd862b4f60245c7 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 17 Oct 2018 17:20:35 -0700 Subject: [PATCH] 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: Kees Cook Reviewed-by: Joel Fernandes (Google) Tested-by: Sai Prakash Ranjan Tested-by: Guenter Roeck --- fs/pstore/ram.c | 16 +++++++++++++--- fs/pstore/ram_core.c | 11 +++++++---- include/linux/pstore_ram.h | 3 ++- 3 files changed, 22 insertions(+), 8 deletions(-) diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 98e48d1a9776..712960e117fe 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -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->ecc_info, + 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); diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c index 951a14edcf51..f200dcefb3b4 100644 --- a/fs/pstore/ram_core.c +++ b/fs/pstore/ram_core.c @@ -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) diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h index e6d226464838..602d64725222 100644 --- a/include/linux/pstore_ram.h +++ b/include/linux/pstore_ram.h @@ -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); -- 2.30.2