[PATCH] pstore/ram: fix undefined usage of rounddown_pow_of_two.

[Florian Fainelli]

From: Maxime Bizon <mbizon@xxxxxxxxxx>

record_size / console_size / ftrace_size can be 0 (this is how you
disable the feature), but rounddown_pow_of_two(0) is undefined. This problem
has been present since commit 1894a253 (ramoops: Move to fs/pstore/ram.c).

Signed-off-by: Maxime Bizon <mbizon@xxxxxxxxxx>
Signed-off-by: Florian Fainelli <ffainelli@xxxxxxxxxx>
CC: stable@xxxxxxxxxxxxxxx
---
 fs/pstore/ram.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 1a4f6da..0c2ae26 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -374,10 +374,14 @@ static int __devinit ramoops_probe(struct platform_device *pdev)
 		goto fail_out;
 	}
 
-	pdata->mem_size = rounddown_pow_of_two(pdata->mem_size);
-	pdata->record_size = rounddown_pow_of_two(pdata->record_size);
-	pdata->console_size = rounddown_pow_of_two(pdata->console_size);
-	pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
+	if (pdata->mem_size)
+		pdata->mem_size = rounddown_pow_of_two(pdata->mem_size);
+	if (pdata->record_size)
+		pdata->record_size = rounddown_pow_of_two(pdata->record_size);
+	if (pdata->console_size)
+		pdata->console_size = rounddown_pow_of_two(pdata->console_size);
+	if (pdata->ftrace_size)
+		pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
 
 	cxt->dump_read_cnt = 0;
 	cxt->size = pdata->mem_size;
-- 
1.7.9.5

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