On Tue, 19 Dec 2023 21:34:15 +0000 Justin Stitt <justinstitt@xxxxxxxxxx> wrote: > We're doing some needless string copies when trying to assign the proper > `prop` string. We can make `prop` a const char* and simply assign to > string literals. > > For the case where a format string is used, let's extract the parsing > logic out into sx9324_parse_phase_prop(). We no longer need to create > copies or allocate new memory. > > sx9324_parse_phase_prop() will simply return the default def value if it > fails. > > This also cleans up some deprecated strncpy() uses [1]. > > Furthermore, let's clean up this code further by removing some unused > defines: > | #define SX9324_PIN_DEF "semtech,ph0-pin" > | #define SX9324_RESOLUTION_DEF "semtech,ph01-resolution" > | #define SX9324_PROXRAW_DEF "semtech,ph01-proxraw-strength" > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] > Link: https://github.com/KSPP/linux/issues/90 > Cc: linux-hardening@xxxxxxxxxxxxxxx > Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx> This clashes with a patch from Andy Shevchenko iio: proximity: sx9324: Switch to device_property_match_property_string() https://lore.kernel.org/all/20230808162800.61651-7-andriy.shevchenko@xxxxxxxxxxxxxxx/ Would you mind rebasing on top of that (it should be in linux-next or my togreg branch of iio.git). Might be easier to rebase on rc1 once it's available in about 3.5 weeks time. Jonathan > --- > Changes in v4: > - use u8 return type (thanks Stephen) > - remove unused defines (thanks Stephen et al.) > - tweaks to sx9324_parse_phase_prop related to defaults (thanks Stephen) > - Link to v3: https://lore.kernel.org/r/20231212-strncpy-drivers-iio-proximity-sx9324-c-v3-1-b8ae12fc8a5d@xxxxxxxxxx > > Changes in v3: > - extract logic into sx9324_parse_phase_prop() and use string literals > (thanks Stephen) > - rebase onto mainline bee0e7762ad2c602 > - Link to v2: https://lore.kernel.org/r/20231026-strncpy-drivers-iio-proximity-sx9324-c-v2-1-cee6e5db700c@xxxxxxxxxx > > Changes in v2: > - make prop a const char* and do simple assignments (thanks Jonathan) > - rebase onto 3a568e3a961ba330 > - Link to v1: https://lore.kernel.org/r/20230921-strncpy-drivers-iio-proximity-sx9324-c-v1-1-4e8d28fd1e7c@xxxxxxxxxx > --- > --- > drivers/iio/proximity/sx9324.c | 70 ++++++++++++++++++++++++------------------ > 1 file changed, 40 insertions(+), 30 deletions(-) > > diff --git a/drivers/iio/proximity/sx9324.c b/drivers/iio/proximity/sx9324.c > index 438f9c9aba6e..3daad7167c63 100644 > --- a/drivers/iio/proximity/sx9324.c > +++ b/drivers/iio/proximity/sx9324.c > @@ -873,6 +873,29 @@ static int sx9324_init_compensation(struct iio_dev *indio_dev) > 20000, 2000000); > } > > +static u8 sx9324_parse_phase_prop(struct device *dev, > + struct sx_common_reg_default *reg_def, > + const char *prop) > +{ > + unsigned int pin_defs[SX9324_NUM_PINS]; > + int count, ret, pin; > + u32 raw = 0; > + > + count = device_property_count_u32(dev, prop); > + if (count != ARRAY_SIZE(pin_defs)) > + return reg_def->def; > + ret = device_property_read_u32_array(dev, prop, pin_defs, > + ARRAY_SIZE(pin_defs)); > + if (ret) > + return reg_def->def; > + > + for (pin = 0; pin < SX9324_NUM_PINS; pin++) > + raw |= (pin_defs[pin] << (2 * pin)) & > + SX9324_REG_AFE_PH0_PIN_MASK(pin); > + > + return raw; > +} > + > static const struct sx_common_reg_default * > sx9324_get_default_reg(struct device *dev, int idx, > struct sx_common_reg_default *reg_def) > @@ -881,38 +904,29 @@ sx9324_get_default_reg(struct device *dev, int idx, > "highest" }; > static const char * const sx9324_csidle[] = { "hi-z", "hi-z", "gnd", > "vdd" }; > -#define SX9324_PIN_DEF "semtech,ph0-pin" > -#define SX9324_RESOLUTION_DEF "semtech,ph01-resolution" > -#define SX9324_PROXRAW_DEF "semtech,ph01-proxraw-strength" > - unsigned int pin_defs[SX9324_NUM_PINS]; > - char prop[] = SX9324_PROXRAW_DEF; > u32 start = 0, raw = 0, pos = 0; > - int ret, count, ph, pin; > - const char *res; > + const char *prop, *res; > + int ret; > > memcpy(reg_def, &sx9324_default_regs[idx], sizeof(*reg_def)); > > sx_common_get_raw_register_config(dev, reg_def); > switch (reg_def->reg) { > case SX9324_REG_AFE_PH0: > + reg_def->def = sx9324_parse_phase_prop(dev, reg_def, > + "semtech,ph0-pin"); > + break; > case SX9324_REG_AFE_PH1: > + reg_def->def = sx9324_parse_phase_prop(dev, reg_def, > + "semtech,ph1-pin"); > + break; > case SX9324_REG_AFE_PH2: > + reg_def->def = sx9324_parse_phase_prop(dev, reg_def, > + "semtech,ph2-pin"); > + break; > case SX9324_REG_AFE_PH3: > - ph = reg_def->reg - SX9324_REG_AFE_PH0; > - snprintf(prop, ARRAY_SIZE(prop), "semtech,ph%d-pin", ph); > - > - count = device_property_count_u32(dev, prop); > - if (count != ARRAY_SIZE(pin_defs)) > - break; > - ret = device_property_read_u32_array(dev, prop, pin_defs, > - ARRAY_SIZE(pin_defs)); > - if (ret) > - break; > - > - for (pin = 0; pin < SX9324_NUM_PINS; pin++) > - raw |= (pin_defs[pin] << (2 * pin)) & > - SX9324_REG_AFE_PH0_PIN_MASK(pin); > - reg_def->def = raw; > + reg_def->def = sx9324_parse_phase_prop(dev, reg_def, > + "semtech,ph3-pin"); > break; > case SX9324_REG_AFE_CTRL0: > ret = device_property_read_string(dev, > @@ -937,11 +951,9 @@ sx9324_get_default_reg(struct device *dev, int idx, > case SX9324_REG_AFE_CTRL4: > case SX9324_REG_AFE_CTRL7: > if (reg_def->reg == SX9324_REG_AFE_CTRL4) > - strncpy(prop, "semtech,ph01-resolution", > - ARRAY_SIZE(prop)); > + prop = "semtech,ph01-resolution"; > else > - strncpy(prop, "semtech,ph23-resolution", > - ARRAY_SIZE(prop)); > + prop = "semtech,ph23-resolution"; > > ret = device_property_read_u32(dev, prop, &raw); > if (ret) > @@ -1012,11 +1024,9 @@ sx9324_get_default_reg(struct device *dev, int idx, > case SX9324_REG_PROX_CTRL0: > case SX9324_REG_PROX_CTRL1: > if (reg_def->reg == SX9324_REG_PROX_CTRL0) > - strncpy(prop, "semtech,ph01-proxraw-strength", > - ARRAY_SIZE(prop)); > + prop = "semtech,ph01-proxraw-strength"; > else > - strncpy(prop, "semtech,ph23-proxraw-strength", > - ARRAY_SIZE(prop)); > + prop = "semtech,ph23-proxraw-strength"; > ret = device_property_read_u32(dev, prop, &raw); > if (ret) > break; > > --- > base-commit: bee0e7762ad2c6025b9f5245c040fcc36ef2bde8 > change-id: 20230921-strncpy-drivers-iio-proximity-sx9324-c-8c3437676039 > > Best regards, > -- > Justin Stitt <justinstitt@xxxxxxxxxx> >
