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pstore: Add pmsg - user-space accessible pstore object

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A secured user-space accessible pstore object. Writes
to /dev/pmsg0 are appended to the buffer, on reboot
the persistent contents are available in
/sys/fs/pstore/pmsg-ramoops-[ID].

One possible use is syslogd, or other daemon, can
write messages, then on reboot provides a means to
triage user-space activities leading up to a panic
as a companion to the pstore dmesg or console logs.

Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
Mark Salyzyn
2015-01-16 16:01:10 -08:00
committed by Tony Luck
parent f44f96528a
commit 9d5438f462
9 changed files with 170 additions and 2 deletions
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34
fs/pstore/ram.c
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@@ -51,6 +51,10 @@ static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
MODULE_PARM_DESC(pmsg_size, "size of user space message log");
static ulong mem_address;
module_param(mem_address, ulong, 0400);
MODULE_PARM_DESC(mem_address,
@@ -82,12 +86,14 @@ struct ramoops_context {
struct persistent_ram_zone **przs;
struct persistent_ram_zone *cprz;
struct persistent_ram_zone *fprz;
struct persistent_ram_zone *mprz;
phys_addr_t phys_addr;
unsigned long size;
unsigned int memtype;
size_t record_size;
size_t console_size;
size_t ftrace_size;
size_t pmsg_size;
int dump_oops;
struct persistent_ram_ecc_info ecc_info;
unsigned int max_dump_cnt;
@@ -96,6 +102,7 @@ struct ramoops_context {
unsigned int dump_read_cnt;
unsigned int console_read_cnt;
unsigned int ftrace_read_cnt;
unsigned int pmsg_read_cnt;
struct pstore_info pstore;
};
@@ -109,6 +116,7 @@ static int ramoops_pstore_open(struct pstore_info *psi)
cxt->dump_read_cnt = 0;
cxt->console_read_cnt = 0;
cxt->ftrace_read_cnt = 0;
cxt->pmsg_read_cnt = 0;
return 0;
}
@@ -190,6 +198,9 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
if (!prz_ok(prz))
prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
1, id, type, PSTORE_TYPE_FTRACE, 0);
if (!prz_ok(prz))
prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
1, id, type, PSTORE_TYPE_PMSG, 0);
if (!prz_ok(prz))
return 0;
@@ -258,6 +269,11 @@ static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
return -ENOMEM;
persistent_ram_write(cxt->fprz, buf, size);
return 0;
} else if (type == PSTORE_TYPE_PMSG) {
if (!cxt->mprz)
return -ENOMEM;
persistent_ram_write(cxt->mprz, buf, size);
return 0;
}
if (type != PSTORE_TYPE_DMESG)
@@ -315,6 +331,9 @@ static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
case PSTORE_TYPE_FTRACE:
prz = cxt->fprz;
break;
case PSTORE_TYPE_PMSG:
prz = cxt->mprz;
break;
default:
return -EINVAL;
}
@@ -441,7 +460,7 @@ static int ramoops_probe(struct platform_device *pdev)
goto fail_out;
if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
!pdata->ftrace_size)) {
!pdata->ftrace_size && !pdata->pmsg_size)) {
pr_err("The memory size and the record/console size must be "
"non-zero\n");
goto fail_out;
@@ -453,6 +472,8 @@ static int ramoops_probe(struct platform_device *pdev)
pdata->console_size = rounddown_pow_of_two(pdata->console_size);
if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
cxt->size = pdata->mem_size;
cxt->phys_addr = pdata->mem_address;
@@ -460,12 +481,14 @@ static int ramoops_probe(struct platform_device *pdev)
cxt->record_size = pdata->record_size;
cxt->console_size = pdata->console_size;
cxt->ftrace_size = pdata->ftrace_size;
cxt->pmsg_size = pdata->pmsg_size;
cxt->dump_oops = pdata->dump_oops;
cxt->ecc_info = pdata->ecc_info;
paddr = cxt->phys_addr;
dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size;
dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
- cxt->pmsg_size;
err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
if (err)
goto fail_out;
@@ -480,6 +503,10 @@ static int ramoops_probe(struct platform_device *pdev)
if (err)
goto fail_init_fprz;
err = ramoops_init_prz(dev, cxt, &cxt->mprz, &paddr, cxt->pmsg_size, 0);
if (err)
goto fail_init_mprz;
cxt->pstore.data = cxt;
/*
* Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
@@ -523,6 +550,8 @@ fail_buf:
kfree(cxt->pstore.buf);
fail_clear:
cxt->pstore.bufsize = 0;
kfree(cxt->mprz);
fail_init_mprz:
kfree(cxt->fprz);
fail_init_fprz:
kfree(cxt->cprz);
@@ -580,6 +609,7 @@ static void ramoops_register_dummy(void)
dummy_data->record_size = record_size;
dummy_data->console_size = ramoops_console_size;
dummy_data->ftrace_size = ramoops_ftrace_size;
dummy_data->pmsg_size = ramoops_pmsg_size;
dummy_data->dump_oops = dump_oops;
/*
* For backwards compatibility ramoops.ecc=1 means 16 bytes ECC