Commit 26961d76 authored by Kees Cook's avatar Kees Cook
Browse files

pstore/ram: Refactor DT size parsing 

Refactor device tree size parsing routines to be able to pass a non-zero
default value for providing a configurable default for the coming
"max_reason" field. Also rename the helpers, since we're not always
parsing a size -- we're parsing a u32 and making sure it's not greater
than INT_MAX.

Link: https://lore.kernel.org/lkml/20200506211523.15077-4-keescook@chromium.org/
Link: https://lore.kernel.org/lkml/20200521205223.175957-1-tyhicks@linux.microsoft.com


Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent f858b57f

fs/pstore/ram.c

+19 −12
Original line number Diff line number Diff line
@@ -644,19 +644,25 @@ static int ramoops_init_prz(const char *name, 
	return 0;

}



static int ramoops_parse_dt_size(struct platform_device *pdev,

				 const char *propname, u32 *value)

/* Read a u32 from a dt property and make sure it's safe for an int. */

static int ramoops_parse_dt_u32(struct platform_device *pdev,

				const char *propname,

				u32 default_value, u32 *value)

{

	u32 val32 = 0;

	int ret;



	ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);

	if (ret < 0 && ret != -EINVAL) {

	if (ret == -EINVAL) {

		/* field is missing, use default value. */

		val32 = default_value;

	} else if (ret < 0) {

		dev_err(&pdev->dev, "failed to parse property %s: %d\n",

			propname, ret);

		return ret;

	}



	/* Sanity check our results. */

	if (val32 > INT_MAX) {

		dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);

		return -EOVERFLOW;
@@ -689,21 +695,22 @@ static int ramoops_parse_dt(struct platform_device *pdev, 
	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);	\

#define parse_u32(name, field, default_value) {				\

		ret = ramoops_parse_dt_u32(pdev, name, default_value,	\

					    &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);

	parse_size("flags", pdata->flags);

	parse_u32("record-size", pdata->record_size, 0);

	parse_u32("console-size", pdata->console_size, 0);

	parse_u32("ftrace-size", pdata->ftrace_size, 0);

	parse_u32("pmsg-size", pdata->pmsg_size, 0);

	parse_u32("ecc-size", pdata->ecc_info.ecc_size, 0);

	parse_u32("flags", pdata->flags, 0);



#undef parse_size

#undef parse_u32



	/*

	 * Some old Chromebooks relied on the kernel setting the

CRA Git | Maintained and supported by SUSTech CRA and CCSE