[PATCH v3 3/6] pstore/ram: Refactor DT size parsing

Kees Cook
2020-05-06T21:15:32Z

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.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
fs/pstore/ram.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 795622190c01..c2f76b650f91 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -645,18 +645,23 @@ static int ramoops_init_prz(const char *name,
}

static int ramoops_parse_dt_size(struct platform_device *pdev,
- const char *propname, u32 *value)
+ 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;
@@ -689,19 +694,20 @@ 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_size(name, field, default_value) { \
+ ret = ramoops_parse_dt_size(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_size("record-size", pdata->record_size, 0);
+ parse_size("console-size", pdata->console_size, 0);
+ parse_size("ftrace-size", pdata->ftrace_size, 0);
+ parse_size("pmsg-size", pdata->pmsg_size, 0);
+ parse_size("ecc-size", pdata->ecc_info.ecc_size, 0);
+ parse_size("flags", pdata->flags, 0);

#undef parse_size

--
2.20.1