| Message ID | 20240903151437.1002990-6-vincenzo.frascino@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | vdso: Use only headers from the vdso/ namespace | expand |
Le 03/09/2024 à 17:14, Vincenzo Frascino a écrit : > The VDSO implementation includes headers from outside of the > vdso/ namespace. > > Split linux/minmax.h to make sure that the generic library > uses only the allowed namespace. It is probably easier to just don't use min_t() in VDSO. Can be open coded without impeeding readability. > > Cc: Andy Lutomirski <luto@kernel.org> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Jason A. Donenfeld <Jason@zx2c4.com> > Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> > --- > include/linux/minmax.h | 28 +--------------------------- > include/vdso/minmax.h | 38 ++++++++++++++++++++++++++++++++++++++ > 2 files changed, 39 insertions(+), 27 deletions(-) > create mode 100644 include/vdso/minmax.h > > diff --git a/include/linux/minmax.h b/include/linux/minmax.h > index 98008dd92153..846e3fa65c96 100644 > --- a/include/linux/minmax.h > +++ b/include/linux/minmax.h > @@ -6,6 +6,7 @@ > #include <linux/compiler.h> > #include <linux/const.h> > #include <linux/types.h> > +#include <vdso/minmax.h> > > /* > * min()/max()/clamp() macros must accomplish three things: > @@ -84,17 +85,6 @@ > #define __types_ok3(x,y,z,ux,uy,uz) \ > (__sign_use(x,ux) & __sign_use(y,uy) & __sign_use(z,uz)) > > -#define __cmp_op_min < > -#define __cmp_op_max > > - > -#define __cmp(op, x, y) ((x) __cmp_op_##op (y) ? (x) : (y)) > - > -#define __cmp_once_unique(op, type, x, y, ux, uy) \ > - ({ type ux = (x); type uy = (y); __cmp(op, ux, uy); }) > - > -#define __cmp_once(op, type, x, y) \ > - __cmp_once_unique(op, type, x, y, __UNIQUE_ID(x_), __UNIQUE_ID(y_)) > - > #define __careful_cmp_once(op, x, y, ux, uy) ({ \ > __auto_type ux = (x); __auto_type uy = (y); \ > BUILD_BUG_ON_MSG(!__types_ok(x,y,ux,uy), \ > @@ -204,22 +194,6 @@ > * Or not use min/max/clamp at all, of course. > */ > > -/** > - * min_t - return minimum of two values, using the specified type > - * @type: data type to use > - * @x: first value > - * @y: second value > - */ > -#define min_t(type, x, y) __cmp_once(min, type, x, y) > - > -/** > - * max_t - return maximum of two values, using the specified type > - * @type: data type to use > - * @x: first value > - * @y: second value > - */ > -#define max_t(type, x, y) __cmp_once(max, type, x, y) > - > /* > * Do not check the array parameter using __must_be_array(). > * In the following legit use-case where the "array" passed is a simple pointer, > diff --git a/include/vdso/minmax.h b/include/vdso/minmax.h > new file mode 100644 > index 000000000000..26724f34c513 > --- /dev/null > +++ b/include/vdso/minmax.h > @@ -0,0 +1,38 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#ifndef __VDSO_MINMAX_H > +#define __VDSO_MINMAX_H > + > +#ifndef __ASSEMBLY__ > + > +#include <linux/compiler.h> > + > +#define __cmp_op_min < > +#define __cmp_op_max > > + > +#define __cmp(op, x, y) ((x) __cmp_op_##op (y) ? (x) : (y)) > + > +#define __cmp_once_unique(op, type, x, y, ux, uy) \ > + ({ type ux = (x); type uy = (y); __cmp(op, ux, uy); }) > + > +#define __cmp_once(op, type, x, y) \ > + __cmp_once_unique(op, type, x, y, __UNIQUE_ID(x_), __UNIQUE_ID(y_)) > + > +/** > + * min_t - return minimum of two values, using the specified type > + * @type: data type to use > + * @x: first value > + * @y: second value > + */ > +#define min_t(type, x, y) __cmp_once(min, type, x, y) > + > +/** > + * max_t - return maximum of two values, using the specified type > + * @type: data type to use > + * @x: first value > + * @y: second value > + */ > +#define max_t(type, x, y) __cmp_once(max, type, x, y) > + > +#endif /* !__ASSEMBLY__ */ > + > +#endif /* __VDSO_MINMAX_H */
On Wed, Sep 4, 2024, at 17:17, Christophe Leroy wrote: > Le 03/09/2024 à 17:14, Vincenzo Frascino a écrit : >> The VDSO implementation includes headers from outside of the >> vdso/ namespace. >> >> Split linux/minmax.h to make sure that the generic library >> uses only the allowed namespace. > > It is probably easier to just don't use min_t() in VDSO. Can be open > coded without impeeding readability. Right, or possibly the even simpler MIN()/MAX() if the arguments have no side-effects. Arnd
On 04/09/2024 18:23, Arnd Bergmann wrote: > On Wed, Sep 4, 2024, at 17:17, Christophe Leroy wrote: >> Le 03/09/2024 à 17:14, Vincenzo Frascino a écrit : >>> The VDSO implementation includes headers from outside of the >>> vdso/ namespace. >>> >>> Split linux/minmax.h to make sure that the generic library >>> uses only the allowed namespace. >> >> It is probably easier to just don't use min_t() in VDSO. Can be open >> coded without impeeding readability. > > Right, or possibly the even simpler MIN()/MAX() if the arguments > have no side-effects. > Agreed, generally I do not like open-coding since it tends to introduce duplication, but these cases are simple especially if we can use MIN()/MAX(). > Arnd
From: Vincenzo Frascino > Sent: 06 September 2024 12:41 > > On 04/09/2024 18:23, Arnd Bergmann wrote: > > On Wed, Sep 4, 2024, at 17:17, Christophe Leroy wrote: > >> Le 03/09/2024 à 17:14, Vincenzo Frascino a écrit : > >>> The VDSO implementation includes headers from outside of the > >>> vdso/ namespace. > >>> > >>> Split linux/minmax.h to make sure that the generic library > >>> uses only the allowed namespace. > >> > >> It is probably easier to just don't use min_t() in VDSO. Can be open > >> coded without impeeding readability. > > > > Right, or possibly the even simpler MIN()/MAX() if the arguments > > have no side-effects. > > > > Agreed, generally I do not like open-coding since it tends to introduce > duplication, but these cases are simple especially if we can use MIN()/MAX(). Aren't MIN()/MAX() likely to get defined in minmax.h for cases where the arguments are constants - and maybe have checks that they are constants. So you don't want to define them in the VDSO header either. Open coding simple cases is actually easier to read :-) David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
diff --git a/include/linux/minmax.h b/include/linux/minmax.h index 98008dd92153..846e3fa65c96 100644 --- a/include/linux/minmax.h +++ b/include/linux/minmax.h @@ -6,6 +6,7 @@ #include <linux/compiler.h> #include <linux/const.h> #include <linux/types.h> +#include <vdso/minmax.h> /* * min()/max()/clamp() macros must accomplish three things: @@ -84,17 +85,6 @@ #define __types_ok3(x,y,z,ux,uy,uz) \ (__sign_use(x,ux) & __sign_use(y,uy) & __sign_use(z,uz)) -#define __cmp_op_min < -#define __cmp_op_max > - -#define __cmp(op, x, y) ((x) __cmp_op_##op (y) ? (x) : (y)) - -#define __cmp_once_unique(op, type, x, y, ux, uy) \ - ({ type ux = (x); type uy = (y); __cmp(op, ux, uy); }) - -#define __cmp_once(op, type, x, y) \ - __cmp_once_unique(op, type, x, y, __UNIQUE_ID(x_), __UNIQUE_ID(y_)) - #define __careful_cmp_once(op, x, y, ux, uy) ({ \ __auto_type ux = (x); __auto_type uy = (y); \ BUILD_BUG_ON_MSG(!__types_ok(x,y,ux,uy), \ @@ -204,22 +194,6 @@ * Or not use min/max/clamp at all, of course. */ -/** - * min_t - return minimum of two values, using the specified type - * @type: data type to use - * @x: first value - * @y: second value - */ -#define min_t(type, x, y) __cmp_once(min, type, x, y) - -/** - * max_t - return maximum of two values, using the specified type - * @type: data type to use - * @x: first value - * @y: second value - */ -#define max_t(type, x, y) __cmp_once(max, type, x, y) - /* * Do not check the array parameter using __must_be_array(). * In the following legit use-case where the "array" passed is a simple pointer, diff --git a/include/vdso/minmax.h b/include/vdso/minmax.h new file mode 100644 index 000000000000..26724f34c513 --- /dev/null +++ b/include/vdso/minmax.h @@ -0,0 +1,38 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_MINMAX_H +#define __VDSO_MINMAX_H + +#ifndef __ASSEMBLY__ + +#include <linux/compiler.h> + +#define __cmp_op_min < +#define __cmp_op_max > + +#define __cmp(op, x, y) ((x) __cmp_op_##op (y) ? (x) : (y)) + +#define __cmp_once_unique(op, type, x, y, ux, uy) \ + ({ type ux = (x); type uy = (y); __cmp(op, ux, uy); }) + +#define __cmp_once(op, type, x, y) \ + __cmp_once_unique(op, type, x, y, __UNIQUE_ID(x_), __UNIQUE_ID(y_)) + +/** + * min_t - return minimum of two values, using the specified type + * @type: data type to use + * @x: first value + * @y: second value + */ +#define min_t(type, x, y) __cmp_once(min, type, x, y) + +/** + * max_t - return maximum of two values, using the specified type + * @type: data type to use + * @x: first value + * @y: second value + */ +#define max_t(type, x, y) __cmp_once(max, type, x, y) + +#endif /* !__ASSEMBLY__ */ + +#endif /* __VDSO_MINMAX_H */
The VDSO implementation includes headers from outside of the vdso/ namespace. Split linux/minmax.h to make sure that the generic library uses only the allowed namespace. Cc: Andy Lutomirski <luto@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> --- include/linux/minmax.h | 28 +--------------------------- include/vdso/minmax.h | 38 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+), 27 deletions(-) create mode 100644 include/vdso/minmax.h