From 791205e3ec6081a8da6f00621e3453d622dc41e7 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 13 May 2020 14:35:03 -0700 Subject: pstore/ram: Introduce max_reason and convert dump_oops Now that pstore_register() can correctly pass max_reason to the kmesg dump facility, introduce a new "max_reason" module parameter and "max-reason" Device Tree field. The "dump_oops" module parameter and "dump-oops" Device Tree field are now considered deprecated, but are now automatically converted to their corresponding max_reason values when present, though the new max_reason setting has precedence. For struct ramoops_platform_data, the "dump_oops" member is entirely replaced by a new "max_reason" member, with the only existing user updated in place. Additionally remove the "reason" filter logic from ramoops_pstore_write(), as that is not specifically needed anymore, though technically this is a change in behavior for any ramoops users also setting the printk.always_kmsg_dump boot param, which will cause ramoops to behave as if max_reason was set to KMSG_DUMP_MAX. Co-developed-by: Pavel Tatashin Signed-off-by: Pavel Tatashin Link: https://lore.kernel.org/lkml/20200515184434.8470-6-keescook@chromium.org/ Signed-off-by: Kees Cook --- fs/pstore/ram.c | 58 ++++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 39 insertions(+), 19 deletions(-) (limited to 'fs/pstore/ram.c') diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 26a1f502a3ea..ca6d8a867285 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -58,10 +58,10 @@ module_param(mem_type, uint, 0400); MODULE_PARM_DESC(mem_type, "set to 1 to try to use unbuffered memory (default 0)"); -static int dump_oops = 1; -module_param(dump_oops, int, 0400); -MODULE_PARM_DESC(dump_oops, - "set to 1 to dump oopses, 0 to only dump panics (default 1)"); +static int ramoops_max_reason = -1; +module_param_named(max_reason, ramoops_max_reason, int, 0400); +MODULE_PARM_DESC(max_reason, + "maximum reason for kmsg dump (default 2: Oops and Panic) "); static int ramoops_ecc; module_param_named(ecc, ramoops_ecc, int, 0400); @@ -70,6 +70,11 @@ MODULE_PARM_DESC(ramoops_ecc, "ECC buffer size in bytes (1 is a special value, means 16 " "bytes ECC)"); +static int ramoops_dump_oops = -1; +module_param_named(dump_oops, ramoops_dump_oops, int, 0400); +MODULE_PARM_DESC(dump_oops, + "(deprecated: use max_reason instead) set to 1 to dump oopses & panics, 0 to only dump panics"); + struct ramoops_context { struct persistent_ram_zone **dprzs; /* Oops dump zones */ struct persistent_ram_zone *cprz; /* Console zone */ @@ -82,7 +87,6 @@ struct ramoops_context { size_t console_size; size_t ftrace_size; size_t pmsg_size; - int dump_oops; u32 flags; struct persistent_ram_ecc_info ecc_info; unsigned int max_dump_cnt; @@ -336,16 +340,14 @@ static int notrace ramoops_pstore_write(struct pstore_record *record) return -EINVAL; /* - * Out of the various dmesg dump types, ramoops is currently designed - * to only store crash logs, rather than storing general kernel logs. + * We could filter on record->reason here if we wanted to (which + * would duplicate what happened before the "max_reason" setting + * was added), but that would defeat the purpose of a system + * changing printk.always_kmsg_dump, so instead log everything that + * the kmsg dumper sends us, since it should be doing the filtering + * based on the combination of printk.always_kmsg_dump and our + * requested "max_reason". */ - if (record->reason != KMSG_DUMP_OOPS && - record->reason != KMSG_DUMP_PANIC) - return -EINVAL; - - /* Skip Oopes when configured to do so. */ - if (record->reason == KMSG_DUMP_OOPS && !cxt->dump_oops) - return -EINVAL; /* * Explicitly only take the first part of any new crash. @@ -647,7 +649,14 @@ static int ramoops_parse_dt(struct platform_device *pdev, pdata->mem_size = resource_size(res); pdata->mem_address = res->start; pdata->mem_type = of_property_read_bool(of_node, "unbuffered"); - pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops"); + /* + * Setting "no-dump-oops" is deprecated and will be ignored if + * "max_reason" is also specified. + */ + if (of_property_read_bool(of_node, "no-dump-oops")) + pdata->max_reason = KMSG_DUMP_PANIC; + else + pdata->max_reason = KMSG_DUMP_OOPS; #define parse_u32(name, field, default_value) { \ ret = ramoops_parse_dt_u32(pdev, name, default_value, \ @@ -663,6 +672,7 @@ static int ramoops_parse_dt(struct platform_device *pdev, parse_u32("pmsg-size", pdata->pmsg_size, 0); parse_u32("ecc-size", pdata->ecc_info.ecc_size, 0); parse_u32("flags", pdata->flags, 0); + parse_u32("max-reason", pdata->max_reason, pdata->max_reason); #undef parse_u32 @@ -746,7 +756,6 @@ static int ramoops_probe(struct platform_device *pdev) 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->flags = pdata->flags; cxt->ecc_info = pdata->ecc_info; @@ -789,8 +798,10 @@ static int ramoops_probe(struct platform_device *pdev) * the single region size is how to check. */ cxt->pstore.flags = 0; - if (cxt->max_dump_cnt) + if (cxt->max_dump_cnt) { cxt->pstore.flags |= PSTORE_FLAGS_DMESG; + cxt->pstore.max_reason = pdata->max_reason; + } if (cxt->console_size) cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE; if (cxt->max_ftrace_cnt) @@ -826,7 +837,7 @@ static int ramoops_probe(struct platform_device *pdev) mem_size = pdata->mem_size; mem_address = pdata->mem_address; record_size = pdata->record_size; - dump_oops = pdata->dump_oops; + ramoops_max_reason = pdata->max_reason; ramoops_console_size = pdata->console_size; ramoops_pmsg_size = pdata->pmsg_size; ramoops_ftrace_size = pdata->ftrace_size; @@ -909,7 +920,16 @@ static void __init ramoops_register_dummy(void) pdata.console_size = ramoops_console_size; pdata.ftrace_size = ramoops_ftrace_size; pdata.pmsg_size = ramoops_pmsg_size; - pdata.dump_oops = dump_oops; + /* If "max_reason" is set, its value has priority over "dump_oops". */ + if (ramoops_max_reason >= 0) + pdata.max_reason = ramoops_max_reason; + /* Otherwise, if "dump_oops" is set, parse it into "max_reason". */ + else if (ramoops_dump_oops != -1) + pdata.max_reason = ramoops_dump_oops ? KMSG_DUMP_OOPS + : KMSG_DUMP_PANIC; + /* And if neither are explicitly set, use the default. */ + else + pdata.max_reason = KMSG_DUMP_OOPS; pdata.flags = RAMOOPS_FLAG_FTRACE_PER_CPU; /* -- cgit v1.2.3-58-ga151