On Thu, Jul 28, 2016 at 2:10 PM, Rob Herring <robh@xxxxxxxxxx> wrote: > On Thu, Jul 28, 2016 at 3:50 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote: >> On Thu, Jul 28, 2016 at 1:25 PM, Rob Herring <robh@xxxxxxxxxx> wrote: >>> This reverts commit 35da60941e44dbf57868e67686dd24cc1a33125a. >>> --- >>> WTF! >>> >>> I don't recall acking this nor have my comments (Arnd's really) been >>> addressed[1]. This should not have been merged yet. >> >> The conversation seemed to me to describe an alternative that could be >> moved to, but that it was going to need more work. In the meantime, >> these are the DT bindings used in real devices already. It seemed >> clear to me that reducing the delta now and improving the >> implementation in the future was the right thing to do in this case. I >> didn't think your comments were a hard NAK, but rather a "we should do >> this in the future", and I added it as a TODO for the pstore tree. >> >> Is a revert really justified here? This doesn't break anything (quite >> the opposite, actually). > > Yes. Bindings are an ABI, so they can't evolve other than get > additional properties. Okay. I still think that from a pragmatic perspective, this isn't different from reality: Android carries a version of this, so that ABI already "exists", but, regardless, I misunderstood the intensity of your concerns. :) > I'm keen to have this in too because I know there are lots of users > (extract a DT from a Calxeda system ;)). It's not really that far off > (drop memory-region and define the location in /reserved-memory) I > think. So send a follow-up for 4.8 and then it doesn't need a revert. Okay, I'll see what I can figure out. -Kees > > Rob > >> >> -Kees >> >>> >>> Rob >>> >>> [1] https://lkml.org/lkml/2016/6/21/969 >>> >>> Documentation/devicetree/bindings/misc/ramoops.txt | 48 ----------- >>> Documentation/ramoops.txt | 6 +- >>> fs/pstore/ram.c | 95 +--------------------- >>> 3 files changed, 4 insertions(+), 145 deletions(-) >>> delete mode 100644 Documentation/devicetree/bindings/misc/ramoops.txt >>> >>> diff --git a/Documentation/devicetree/bindings/misc/ramoops.txt b/Documentation/devicetree/bindings/misc/ramoops.txt >>> deleted file mode 100644 >>> index cd02cec..0000000 >>> --- a/Documentation/devicetree/bindings/misc/ramoops.txt >>> +++ /dev/null >>> @@ -1,48 +0,0 @@ >>> -Ramoops oops/panic logger >>> -========================= >>> - >>> -ramoops provides persistent RAM storage for oops and panics, so they can be >>> -recovered after a reboot. It is a backend to pstore, so this node is named >>> -"ramoops" after the backend, rather than "pstore" which is the subsystem. >>> - >>> -Parts of this storage may be set aside for other persistent log buffers, such >>> -as kernel log messages, or for optional ECC error-correction data. The total >>> -size of these optional buffers must fit in the reserved region. >>> - >>> -Any remaining space will be used for a circular buffer of oops and panic >>> -records. These records have a configurable size, with a size of 0 indicating >>> -that they should be disabled. >>> - >>> -At least one of "record-size", "console-size", "ftrace-size", or "pmsg-size" >>> -must be set non-zero, but are otherwise optional as listed below. >>> - >>> - >>> -Required properties: >>> - >>> -- compatible: must be "ramoops" >>> - >>> -- memory-region: phandle to a region of memory that is preserved between >>> - reboots >>> - >>> - >>> -Optional properties: >>> - >>> -- ecc-size: enables ECC support and specifies ECC buffer size in bytes >>> - (defaults to 0: no ECC) >>> - >>> -- record-size: maximum size in bytes of each dump done on oops/panic >>> - (defaults to 0: disabled) >>> - >>> -- console-size: size in bytes of log buffer reserved for kernel messages >>> - (defaults to 0: disabled) >>> - >>> -- ftrace-size: size in bytes of log buffer reserved for function tracing and >>> - profiling (defaults to 0: disabled) >>> - >>> -- pmsg-size: size in bytes of log buffer reserved for userspace messages >>> - (defaults to 0: disabled) >>> - >>> -- unbuffered: if present, use unbuffered mappings to map the reserved region >>> - (defaults to buffered mappings) >>> - >>> -- no-dump-oops: if present, only dump panics (defaults to panics and oops) >>> diff --git a/Documentation/ramoops.txt b/Documentation/ramoops.txt >>> index 9264bca..5d86756 100644 >>> --- a/Documentation/ramoops.txt >>> +++ b/Documentation/ramoops.txt >>> @@ -45,7 +45,7 @@ corrupt, but usually it is restorable. >>> >>> 2. Setting the parameters >>> >>> -Setting the ramoops parameters can be done in 3 different manners: >>> +Setting the ramoops parameters can be done in 2 different manners: >>> 1. Use the module parameters (which have the names of the variables described >>> as before). >>> For quick debugging, you can also reserve parts of memory during boot >>> @@ -54,9 +54,7 @@ Setting the ramoops parameters can be done in 3 different manners: >>> kernel to use only the first 128 MB of memory, and place ECC-protected ramoops >>> region at 128 MB boundary: >>> "mem=128M ramoops.mem_address=0x8000000 ramoops.ecc=1" >>> - 2. Use Device Tree bindings, as described in >>> - Documentation/device-tree/bindings/misc/ramoops.txt. >>> - 3. Use a platform device and set the platform data. The parameters can then >>> + 2. Use a platform device and set the platform data. The parameters can then >>> be set through that platform data. An example of doing that is: >>> >>> #include <linux/pstore_ram.h> >>> diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c >>> index 47516a7..d9668c2 100644 >>> --- a/fs/pstore/ram.c >>> +++ b/fs/pstore/ram.c >>> @@ -34,8 +34,6 @@ >>> #include <linux/slab.h> >>> #include <linux/compiler.h> >>> #include <linux/pstore_ram.h> >>> -#include <linux/of.h> >>> -#include <linux/of_address.h> >>> >>> #define RAMOOPS_KERNMSG_HDR "====" >>> #define MIN_MEM_SIZE 4096UL >>> @@ -460,98 +458,15 @@ static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt, >>> return 0; >>> } >>> >>> -static int ramoops_parse_dt_size(struct platform_device *pdev, >>> - const char *propname, u32 *value) >>> -{ >>> - u32 val32 = 0; >>> - int ret; >>> - >>> - ret = of_property_read_u32(pdev->dev.of_node, propname, &val32); >>> - if (ret < 0 && ret != -EINVAL) { >>> - dev_err(&pdev->dev, "failed to parse property %s: %d\n", >>> - propname, ret); >>> - return ret; >>> - } >>> - >>> - if (val32 > INT_MAX) { >>> - dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32); >>> - return -EOVERFLOW; >>> - } >>> - >>> - *value = val32; >>> - return 0; >>> -} >>> - >>> -static int ramoops_parse_dt(struct platform_device *pdev, >>> - struct ramoops_platform_data *pdata) >>> -{ >>> - struct device_node *of_node = pdev->dev.of_node; >>> - struct device_node *mem_region; >>> - struct resource res; >>> - u32 value; >>> - int ret; >>> - >>> - dev_dbg(&pdev->dev, "using Device Tree\n"); >>> - >>> - mem_region = of_parse_phandle(of_node, "memory-region", 0); >>> - if (!mem_region) { >>> - dev_err(&pdev->dev, "no memory-region phandle\n"); >>> - return -ENODEV; >>> - } >>> - >>> - ret = of_address_to_resource(mem_region, 0, &res); >>> - of_node_put(mem_region); >>> - if (ret) { >>> - dev_err(&pdev->dev, >>> - "failed to translate memory-region to resource: %d\n", >>> - ret); >>> - return ret; >>> - } >>> - >>> - 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"); >>> - >>> -#define parse_size(name, field) { \ >>> - ret = ramoops_parse_dt_size(pdev, name, &value); \ >>> - if (ret < 0) \ >>> - return ret; \ >>> - field = value; \ >>> - } >>> - >>> - parse_size("record-size", pdata->record_size); >>> - parse_size("console-size", pdata->console_size); >>> - parse_size("ftrace-size", pdata->ftrace_size); >>> - parse_size("pmsg-size", pdata->pmsg_size); >>> - parse_size("ecc-size", pdata->ecc_info.ecc_size); >>> - >>> -#undef parse_size >>> - >>> - return 0; >>> -} >>> - >>> static int ramoops_probe(struct platform_device *pdev) >>> { >>> struct device *dev = &pdev->dev; >>> - struct ramoops_platform_data *pdata = dev->platform_data; >>> + struct ramoops_platform_data *pdata = pdev->dev.platform_data; >>> struct ramoops_context *cxt = &oops_cxt; >>> size_t dump_mem_sz; >>> phys_addr_t paddr; >>> int err = -EINVAL; >>> >>> - if (dev_of_node(dev) && !pdata) { >>> - pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); >>> - if (!pdata) { >>> - err = -ENOMEM; >>> - goto fail_out; >>> - } >>> - >>> - err = ramoops_parse_dt(pdev, pdata); >>> - if (err < 0) >>> - goto fail_out; >>> - } >>> - >>> /* Only a single ramoops area allowed at a time, so fail extra >>> * probes. >>> */ >>> @@ -681,17 +596,11 @@ static int ramoops_remove(struct platform_device *pdev) >>> return 0; >>> } >>> >>> -static const struct of_device_id dt_match[] = { >>> - { .compatible = "ramoops" }, >>> - {} >>> -}; >>> - >>> static struct platform_driver ramoops_driver = { >>> .probe = ramoops_probe, >>> .remove = ramoops_remove, >>> .driver = { >>> - .name = "ramoops", >>> - .of_match_table = dt_match, >>> + .name = "ramoops", >>> }, >>> }; >>> >>> -- >>> 2.9.2 >>> >> >> >> >> -- >> Kees Cook >> Chrome OS & Brillo Security -- Kees Cook Chrome OS & Brillo Security -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
