| Message ID | 1591603981-16879-9-git-send-email-pmorel@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | s390x: Testing the Channel Subsystem I/O | expand |
On 08/06/2020 10.12, Pierre Morel wrote: > We often need to retrieve hexadecimal kernel parameters. > Let's implement a shared utility to do it. > > Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> > --- > lib/s390x/kernel-args.c | 60 +++++++++++++++++++++++++++++++++++++++++ > lib/s390x/kernel-args.h | 18 +++++++++++++ > s390x/Makefile | 1 + > 3 files changed, 79 insertions(+) > create mode 100644 lib/s390x/kernel-args.c > create mode 100644 lib/s390x/kernel-args.h [...] > +int kernel_arg(int argc, char *argv[], const char *str, unsigned long *val) > +{ > + int i, ret; > + char *p; > + > + for (i = 0; i < argc; i++) { > + ret = strncmp(argv[i], str, strlen(str)); > + if (ret) > + continue; > + p = strchr(argv[i], '='); > + if (!p) > + return -1; > + p = strchr(p, 'x'); > + if (!p) > + *val = atol(p + 1); If p is NULL, then you call atol(NULL + 1) ... I think you need another temporary variable here instead to hold the new pointer / NULL value? Thomas
On 2020-06-09 07:21, Thomas Huth wrote: > On 08/06/2020 10.12, Pierre Morel wrote: >> We often need to retrieve hexadecimal kernel parameters. >> Let's implement a shared utility to do it. >> >> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> >> --- >> lib/s390x/kernel-args.c | 60 +++++++++++++++++++++++++++++++++++++++++ >> lib/s390x/kernel-args.h | 18 +++++++++++++ >> s390x/Makefile | 1 + >> 3 files changed, 79 insertions(+) >> create mode 100644 lib/s390x/kernel-args.c >> create mode 100644 lib/s390x/kernel-args.h > [...] >> +int kernel_arg(int argc, char *argv[], const char *str, unsigned long *val) >> +{ >> + int i, ret; >> + char *p; >> + >> + for (i = 0; i < argc; i++) { >> + ret = strncmp(argv[i], str, strlen(str)); >> + if (ret) >> + continue; >> + p = strchr(argv[i], '='); >> + if (!p) >> + return -1; >> + p = strchr(p, 'x'); >> + if (!p) >> + *val = atol(p + 1); > > If p is NULL, then you call atol(NULL + 1) ... I think you need another > temporary variable here instead to hold the new pointer / NULL value? grrrr, clearly! > > Thomas > Thanks, Pierre
diff --git a/lib/s390x/kernel-args.c b/lib/s390x/kernel-args.c new file mode 100644 index 0000000..3335fbf --- /dev/null +++ b/lib/s390x/kernel-args.c @@ -0,0 +1,60 @@ +/* + * Retrieving kernel arguments + * + * Copyright (c) 2020 IBM Corp + * + * Authors: + * Pierre Morel <pmorel@linux.ibm.com> + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2. + */ + +#include <libcflat.h> +#include <string.h> +#include <asm/arch_def.h> +#include <kernel-args.h> + +static const char *hex_digit = "0123456789abcdef"; + +static unsigned long htol(char *s) +{ + unsigned long v = 0, shift = 0, value = 0; + int i, digit, len = strlen(s); + + for (shift = 0, i = len - 1; i >= 0; i--, shift += 4) { + digit = s[i] | 0x20; /* Set lowercase */ + if (!strchr(hex_digit, digit)) + return 0; /* this is not a digit ! */ + + if (digit <= '9') + v = digit - '0'; + else + v = digit - 'a' + 10; + value += (v << shift); + } + + return value; +} + +int kernel_arg(int argc, char *argv[], const char *str, unsigned long *val) +{ + int i, ret; + char *p; + + for (i = 0; i < argc; i++) { + ret = strncmp(argv[i], str, strlen(str)); + if (ret) + continue; + p = strchr(argv[i], '='); + if (!p) + return -1; + p = strchr(p, 'x'); + if (!p) + *val = atol(p + 1); + else + *val = htol(p + 1); + return 0; + } + return -2; +} diff --git a/lib/s390x/kernel-args.h b/lib/s390x/kernel-args.h new file mode 100644 index 0000000..a88e34e --- /dev/null +++ b/lib/s390x/kernel-args.h @@ -0,0 +1,18 @@ +/* + * Kernel argument + * + * Copyright (c) 2020 IBM Corp + * + * Authors: + * Pierre Morel <pmorel@linux.ibm.com> + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2. + */ + +#ifndef KERNEL_ARGS_H +#define KERNEL_ARGS_H + +int kernel_arg(int argc, char *argv[], const char *str, unsigned long *val); + +#endif diff --git a/s390x/Makefile b/s390x/Makefile index ddb4b48..47a94cc 100644 --- a/s390x/Makefile +++ b/s390x/Makefile @@ -51,6 +51,7 @@ cflatobjs += lib/s390x/sclp-console.o cflatobjs += lib/s390x/interrupt.o cflatobjs += lib/s390x/mmu.o cflatobjs += lib/s390x/smp.o +cflatobjs += lib/s390x/kernel-args.o OBJDIRS += lib/s390x
We often need to retrieve hexadecimal kernel parameters. Let's implement a shared utility to do it. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> --- lib/s390x/kernel-args.c | 60 +++++++++++++++++++++++++++++++++++++++++ lib/s390x/kernel-args.h | 18 +++++++++++++ s390x/Makefile | 1 + 3 files changed, 79 insertions(+) create mode 100644 lib/s390x/kernel-args.c create mode 100644 lib/s390x/kernel-args.h