Coverity report INTEGER_OVERFLOW for host->tuning_err.
The tuning_err field in struct sdhci_host is used to store an error
code for re-tuning, but it was declared as unsigned int. Several call
sites store negative error codes into it and later compare against
negative values:
- sdhci.c, sdhci-of-dwcmshc.c and sdhci-pci-gli.c assign it the
return value of __sdhci_execute_tuning()/__sdhci_execute_tuning_9750(),
both of which return a signed int (possibly a negative errno);
- sdhci-of-esdhc.c assigns host->tuning_err = -EAGAIN and later does
"ret = host->tuning_err; if (ret == -EAGAIN ...)";
- sdhci-of-dwcmshc.c prints it with the %d (signed) conversion.
Storing a negative errno in an unsigned int and reading it back as a
signed int only happens to work because of two's-complement, same-width
integer conversions. It is misleading and triggers sign-conversion
warnings. All users treat the value either as a signed error code or as
a boolean (zero / non-zero), so changing the type to a signed int is
safe and makes the intent explicit.
Fixes: 7d8bb1f46e13 ("mmc: sdhci: add tuning error codes")
Assisted-by: Cline:claude-sonnet [read_file, search_files, git]
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulfh@kernel.org>
unsigned int tuning_count; /* Timer count for re-tuning */
unsigned int tuning_mode; /* Re-tuning mode supported by host */
- unsigned int tuning_err; /* Error code for re-tuning */
+ int tuning_err; /* Error code for re-tuning */
#define SDHCI_TUNING_MODE_1 0
#define SDHCI_TUNING_MODE_2 1
#define SDHCI_TUNING_MODE_3 2