Hi Eugeniu, On Fri, Jul 12, 2019 at 2:21 PM Eugeniu Rosca <ero...@de.adit-jv.com> wrote: > > Quote from https://patchwork.ozlabs.org/patch/1104244/#2210814: > > ----------8<----------- > strncmp() is chosen for the sake of paranoid/defensive programming. > Indeed, strncmp() is not really needed when comparing a variable > with a string literal. We expect strcmp() to behave safely even if the > string variable is not NUL-terminated. > > In the same scenario, Linux v5.2-rc7 uses both strcmp() and strncmp(), > but the frequency of strcmp() is higher: > > $ git --version > git version 2.22.0 > $ (Linux 5.2-rc7) git grep -En 'strncmp\([^"]*"[[:alnum:]]+"' | wc -l > 1066 > $ (Linux 5.2-rc7) git grep -En 'strcmp\([^"]*"[[:alnum:]]+"' | wc -l > 1968 > > A quick "strcmp vs strncmp" object size test shows that strcmp() > generates smaller memory footprint (gcc-8, x86_64): > > $ (U-Boot) size cmd/bcb-strncmp.o cmd/bcb-strcmp.o > text data bss dec hex filename > 3373 400 2048 5821 16bd cmd/bcb-strncmp.o > 3314 400 2048 5762 1682 cmd/bcb-strcmp.o > > So, overall, I agree to use strcmp() whenever variables are compared > with string literals. > ----------8<----------- > > Fixes: db7b7a05b267 ("cmd: Add 'bcb' command to read/modify/write BCB fields") > Reported-by: Simon Glass <s...@chromium.org> > Signed-off-by: Eugeniu Rosca <ero...@de.adit-jv.com> > --- > cmd/bcb.c | 42 +++++++++++++++++++++--------------------- > 1 file changed, 21 insertions(+), 21 deletions(-) > > diff --git a/cmd/bcb.c b/cmd/bcb.c > index 3b1c7434e287..c7138a5179a9 100644 > --- a/cmd/bcb.c > +++ b/cmd/bcb.c > @@ -24,17 +24,17 @@ static struct bootloader_message bcb = { { 0 } }; > > static int bcb_cmd_get(char *cmd) > { > - if (!strncmp(cmd, "load", sizeof("load"))) > + if (!strcmp(cmd, "load")) > return BCB_CMD_LOAD; > - if (!strncmp(cmd, "set", sizeof("set"))) > + if (!strcmp(cmd, "set")) > return BCB_CMD_FIELD_SET; > - if (!strncmp(cmd, "clear", sizeof("clear"))) > + if (!strcmp(cmd, "clear")) > return BCB_CMD_FIELD_CLEAR; > - if (!strncmp(cmd, "test", sizeof("test"))) > + if (!strcmp(cmd, "test")) > return BCB_CMD_FIELD_TEST; > - if (!strncmp(cmd, "store", sizeof("store"))) > + if (!strcmp(cmd, "store")) > return BCB_CMD_STORE; > - if (!strncmp(cmd, "dump", sizeof("dump"))) > + if (!strcmp(cmd, "dump")) > return BCB_CMD_FIELD_DUMP; > else > return -1; > @@ -85,21 +85,21 @@ err: > > static int bcb_field_get(char *name, char **field, int *size) > { > - if (!strncmp(name, "command", sizeof("command"))) { > - *field = bcb.command; > - *size = sizeof(bcb.command); > - } else if (!strncmp(name, "status", sizeof("status"))) { > - *field = bcb.status; > - *size = sizeof(bcb.status); > - } else if (!strncmp(name, "recovery", sizeof("recovery"))) { > - *field = bcb.recovery; > - *size = sizeof(bcb.recovery); > - } else if (!strncmp(name, "stage", sizeof("stage"))) { > - *field = bcb.stage; > - *size = sizeof(bcb.stage); > - } else if (!strncmp(name, "reserved", sizeof("reserved"))) { > - *field = bcb.reserved; > - *size = sizeof(bcb.reserved); > + if (!strcmp(name, "command")) { > + *fieldp = bcb.command; > + *sizep = sizeof(bcb.command); > + } else if (!strcmp(name, "status")) { > + *fieldp = bcb.status; > + *sizep = sizeof(bcb.status); > + } else if (!strcmp(name, "recovery")) { > + *fieldp = bcb.recovery; > + *sizep = sizeof(bcb.recovery); > + } else if (!strcmp(name, "stage")) { > + *fieldp = bcb.stage; > + *sizep = sizeof(bcb.stage); > + } else if (!strcmp(name, "reserved")) { > + *fieldp = bcb.reserved; > + *sizep = sizeof(bcb.reserved); > } else { > printf("Error: Unknown bcb field '%s'\n", name); > return -1; > -- > 2.22.0 >
Reviewed-by: Igor Opaniuk <igor.opan...@gmail.com> -- Best regards - Freundliche Grüsse - Meilleures salutations Igor Opaniuk mailto: igor.opan...@gmail.com skype: igor.opanyuk +380 (93) 836 40 67 http://ua.linkedin.com/in/iopaniuk _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
