clk: ti: Fix error handling in ti_clk_parse_divider_data() [Linux 5.0]

clk: ti: Fix error handling in ti_clk_parse_divider_data() [Linux 5.0]

This Linux kernel change "clk: ti: Fix error handling in ti_clk_parse_divider_data()" is included in the Linux 5.0 release. This change is authored by Dan Carpenter <dan.carpenter [at] oracle.com> on Tue Jan 15 22:46:25 2019 +0300. The commit for this change in Linux stable tree is 303aef8 (patch).

clk: ti: Fix error handling in ti_clk_parse_divider_data()

The ti_clk_parse_divider_data() function is only called from
_get_div_table_from_setup().  That function doesn't look at the return
value but instead looks at the "*table" pointer.  In this case, if the
kcalloc() fails then *table is NULL (which means success).  It should
instead be an error pointer.

The ti_clk_parse_divider_data() function has two callers.  One checks
for errors and the other doesn't.  I have fixed it so now both handle
errors.

Fixes: 4f6be5655dc9 ("clk: ti: divider: add driver internal API for parsing divider data")
Signed-off-by: Dan Carpenter <[email protected]>
Acked-by: Tero Kristo <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>

There are 11 lines of Linux source code added/deleted in this change. Code changes to Linux kernel are as follows.

 drivers/clk/ti/divider.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/ti/divider.c b/drivers/clk/ti/divider.c
index 8d77090..0241450 100644
--- a/drivers/clk/ti/divider.c
+++ b/drivers/clk/ti/divider.c
@@ -403,8 +403,10 @@ int ti_clk_parse_divider_data(int *div_table, int num_dividers, int max_div,
    num_dividers = i;

    tmp = kcalloc(valid_div + 1, sizeof(*tmp), GFP_KERNEL);
-   if (!tmp)
+   if (!tmp) {
+       *table = ERR_PTR(-ENOMEM);
        return -ENOMEM;
+   }

    valid_div = 0;
    *width = 0;
@@ -439,6 +441,7 @@ struct clk_hw *ti_clk_build_component_div(struct ti_clk_divider *setup)
 {
    struct clk_omap_divider *div;
    struct clk_omap_reg *reg;
+   int ret;

    if (!setup)
        return NULL;
@@ -458,6 +461,12 @@ struct clk_hw *ti_clk_build_component_div(struct ti_clk_divider *setup)
        div->flags |= CLK_DIVIDER_POWER_OF_TWO;

    div->table = _get_div_table_from_setup(setup, &div->width);
+   if (IS_ERR(div->table)) {
+       ret = PTR_ERR(div->table);
+       kfree(div);
+       return ERR_PTR(ret);
+   }
+

    div->shift = setup->bit_shift;
    div->latch = -EINVAL;

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