| Message ID | 20240923141943.133551-9-vincenzo.frascino@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | vdso: Use only headers from the vdso/ namespace | expand |
On Mon, Sep 23, 2024 at 03:19:43PM +0100, Vincenzo Frascino wrote: > - params->mmap_prot = PROT_READ | PROT_WRITE; > - params->mmap_flags = MAP_DROPPABLE | MAP_ANONYMOUS; > + params->mmap_prot = VDSO_MMAP_PROT; > + params->mmap_flags = VDSO_MMAP_FLAGS; The code that's being deleted is meaningful and descriptive. The code that's being added is confusing. What on earth is a vdso mmap flag? Not only is it indirection, which makes it harder to understand, but its indirection through a meaninglessly generic name that suggests to the user there's some additional property of the vdso or mmap or both that would imply a specific flag for these general things. In reality, the thing in question is about what getrandom.c uses.
Le 23/09/2024 à 16:19, Vincenzo Frascino a écrit : > The VDSO implementation includes headers from outside of the > vdso/ namespace. > > Modify getrandom to take advantage of the refactoring done in the > previous patches and to include only the vdso/ 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/vdso/datapage.h | 1 + > lib/vdso/getrandom.c | 22 +++++++++++----------- > 2 files changed, 12 insertions(+), 11 deletions(-) > > diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h > index b7d6c71f20c1..127f0c51bf01 100644 > --- a/include/vdso/datapage.h > +++ b/include/vdso/datapage.h > @@ -5,6 +5,7 @@ > #ifndef __ASSEMBLY__ > > #include <linux/compiler.h> > +#include <linux/build_bug.h> What in this datapage.h requires this build_bug header ? > #include <uapi/linux/time.h> > #include <uapi/linux/types.h> > #include <uapi/asm-generic/errno-base.h> > diff --git a/lib/vdso/getrandom.c b/lib/vdso/getrandom.c > index 938ca539aaa6..e15d3cf768c9 100644 > --- a/lib/vdso/getrandom.c > +++ b/lib/vdso/getrandom.c > @@ -3,19 +3,19 @@ > * Copyright (C) 2022-2024 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. > */ > > -#include <linux/array_size.h> > -#include <linux/minmax.h> > #include <vdso/datapage.h> > #include <vdso/getrandom.h> > #include <vdso/unaligned.h> > -#include <asm/vdso/getrandom.h> > -#include <uapi/linux/mman.h> > -#include <uapi/linux/random.h> > +#include <vdso/mman.h> This change is not needed, asm/vdso/getrandom.h is in VDSO namespace, and the other two are UAPI headers which must be safe to include in VDSO code as VDSO code in userland code. > +#include <vdso/page.h> > > -#undef PAGE_SIZE > -#undef PAGE_MASK > -#define PAGE_SIZE (1UL << CONFIG_PAGE_SHIFT) > -#define PAGE_MASK (~(PAGE_SIZE - 1)) > +#ifndef ARRAY_SIZE > +#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*x)) > +#endif > + > +#ifndef min_t > +#define min_t(type,a,b) ((type)(a) < (type)(b) ? (type)(a) : (type)(b)) > +#endif Would be better to force undefine/redefine ARRAY_SIZE and min_t instead of defining them only when they don't exist already. > > #define MEMCPY_AND_ZERO_SRC(type, dst, src, len) do { \ > while (len >= sizeof(type)) { \ > @@ -79,8 +79,8 @@ __cvdso_getrandom_data(const struct vdso_rng_data *rng_info, void *buffer, size_ > if (unlikely(opaque_len == ~0UL && !buffer && !len && !flags)) { > struct vgetrandom_opaque_params *params = opaque_state; > params->size_of_opaque_state = sizeof(*state); > - params->mmap_prot = PROT_READ | PROT_WRITE; > - params->mmap_flags = MAP_DROPPABLE | MAP_ANONYMOUS; > + params->mmap_prot = VDSO_MMAP_PROT; > + params->mmap_flags = VDSO_MMAP_FLAGS; At the time being the flags and prot are the same for all architectures, there is no point in introducing VDSO_MMAP_PROT and VDSO_MMAP_FLAGS. Maybe one day that may be needed, but until that day nothing should be changed, unless you already have in mind and describe an architecture that will need that. Christophe > for (size_t i = 0; i < ARRAY_SIZE(params->reserved); ++i) > params->reserved[i] = 0; > return 0;
diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h index b7d6c71f20c1..127f0c51bf01 100644 --- a/include/vdso/datapage.h +++ b/include/vdso/datapage.h @@ -5,6 +5,7 @@ #ifndef __ASSEMBLY__ #include <linux/compiler.h> +#include <linux/build_bug.h> #include <uapi/linux/time.h> #include <uapi/linux/types.h> #include <uapi/asm-generic/errno-base.h> diff --git a/lib/vdso/getrandom.c b/lib/vdso/getrandom.c index 938ca539aaa6..e15d3cf768c9 100644 --- a/lib/vdso/getrandom.c +++ b/lib/vdso/getrandom.c @@ -3,19 +3,19 @@ * Copyright (C) 2022-2024 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. */ -#include <linux/array_size.h> -#include <linux/minmax.h> #include <vdso/datapage.h> #include <vdso/getrandom.h> #include <vdso/unaligned.h> -#include <asm/vdso/getrandom.h> -#include <uapi/linux/mman.h> -#include <uapi/linux/random.h> +#include <vdso/mman.h> +#include <vdso/page.h> -#undef PAGE_SIZE -#undef PAGE_MASK -#define PAGE_SIZE (1UL << CONFIG_PAGE_SHIFT) -#define PAGE_MASK (~(PAGE_SIZE - 1)) +#ifndef ARRAY_SIZE +#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*x)) +#endif + +#ifndef min_t +#define min_t(type,a,b) ((type)(a) < (type)(b) ? (type)(a) : (type)(b)) +#endif #define MEMCPY_AND_ZERO_SRC(type, dst, src, len) do { \ while (len >= sizeof(type)) { \ @@ -79,8 +79,8 @@ __cvdso_getrandom_data(const struct vdso_rng_data *rng_info, void *buffer, size_ if (unlikely(opaque_len == ~0UL && !buffer && !len && !flags)) { struct vgetrandom_opaque_params *params = opaque_state; params->size_of_opaque_state = sizeof(*state); - params->mmap_prot = PROT_READ | PROT_WRITE; - params->mmap_flags = MAP_DROPPABLE | MAP_ANONYMOUS; + params->mmap_prot = VDSO_MMAP_PROT; + params->mmap_flags = VDSO_MMAP_FLAGS; for (size_t i = 0; i < ARRAY_SIZE(params->reserved); ++i) params->reserved[i] = 0; return 0;
The VDSO implementation includes headers from outside of the vdso/ namespace. Modify getrandom to take advantage of the refactoring done in the previous patches and to include only the vdso/ 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/vdso/datapage.h | 1 + lib/vdso/getrandom.c | 22 +++++++++++----------- 2 files changed, 12 insertions(+), 11 deletions(-)