Messages in this thread Patch in this message | | | From | Kamal Mostafa <> | Subject | [PATCH 3.19.y-ckt 163/170] regulator: s5m8767: fix get_register() error handling | Date | Fri, 1 Apr 2016 17:54:09 -0700 |
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3.19.8-ckt18 -stable review patch. If anyone has any objections, please let me know.
---8<------------------------------------------------------------
From: Arnd Bergmann <arnd@arndb.de>
commit e07ff9434167981c993a26d2edbbcb8e13801dbb upstream.
The s5m8767_pmic_probe() function calls s5m8767_get_register() to read data without checking the return code, which produces a compile-time warning when that data is accessed:
drivers/regulator/s5m8767.c: In function 's5m8767_pmic_probe': drivers/regulator/s5m8767.c:924:7: error: 'enable_reg' may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/regulator/s5m8767.c:944:30: error: 'enable_val' may be used uninitialized in this function [-Werror=maybe-uninitialized]
This changes the s5m8767_get_register() function to return a -EINVAL not just for an invalid register number but also for an invalid regulator number, as both would result in returning uninitialized data. The s5m8767_pmic_probe() function is then changed accordingly to fail on a read error, as all the other callers of s5m8767_get_register() already do.
In practice this probably cannot happen, as we don't call s5m8767_get_register() with invalid arguments, but the gcc warning seems valid in principle, in terms writing safe error checking.
Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 9c4c60554acf ("regulator: s5m8767: Convert to use regulator_[enable|disable|is_enabled]_regmap") Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/regulator/s5m8767.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/regulator/s5m8767.c b/drivers/regulator/s5m8767.c index 58f5d3b..27343e1 100644 --- a/drivers/regulator/s5m8767.c +++ b/drivers/regulator/s5m8767.c @@ -202,9 +202,10 @@ static int s5m8767_get_register(struct s5m8767_info *s5m8767, int reg_id, } } - if (i < s5m8767->num_regulators) - *enable_ctrl = - s5m8767_opmode_reg[reg_id][mode] << S5M8767_ENCTRL_SHIFT; + if (i >= s5m8767->num_regulators) + return -EINVAL; + + *enable_ctrl = s5m8767_opmode_reg[reg_id][mode] << S5M8767_ENCTRL_SHIFT; return 0; } @@ -937,8 +938,12 @@ static int s5m8767_pmic_probe(struct platform_device *pdev) else regulators[id].vsel_mask = 0xff; - s5m8767_get_register(s5m8767, id, &enable_reg, + ret = s5m8767_get_register(s5m8767, id, &enable_reg, &enable_val); + if (ret) { + dev_err(s5m8767->dev, "error reading registers\n"); + return ret; + } regulators[id].enable_reg = enable_reg; regulators[id].enable_mask = S5M8767_ENCTRL_MASK; regulators[id].enable_val = enable_val; -- 2.7.4
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