On Fri, 9 Dec 2022 at 14:46, Christophe Leroy <christophe.leroy@xxxxxxxxxx> wrote: > > > > Le 09/12/2022 à 14:38, Xander a écrit : > > > > The pgprot parameter got removed because, according to the commit log, > > for no other apparent reason than it being called with 'PAGE_KERNEL' as > > an argument in the whole kernel. Therefore it got removed. > > This removed the ability to allocate virtual memory with executing rights. > > My use case comes from ioremap(). > > I think this is useful for others too. > > > > I don't see why this pgprot parameter got removed but this is the > > alternative to reverting it to the older 5.7 function. > > Please avoid top-posting, and use only plain text. > > I think you don't answer to Mark's question. > > You are adding a new function that no driver uses apparently. If you are > working on some piece of code that needs this new fonction, you can send > this patch as part of a patch series including that code. > > By the way, when you need executable memory, the fonction to use is > module_alloc(), that's the only function that garanties real executable > memory on all platforms. For instance, on some powerpc, setting the X > bit is not enough to get executable memory in vmalloc space. > > Christophe > Loud and clear, thanks for the feedback. > > > > On Fri, 9 Dec 2022 at 14:17, Mark Rutland <mark.rutland@xxxxxxx > > <mailto:mark.rutland@xxxxxxx>> wrote: > > > > On Fri, Dec 09, 2022 at 02:10:52PM +0100, Xander Moerkerken wrote: > > > From: Xander Moerkerken <xander.moerkerken@xxxxxxxxx > > <mailto:xander.moerkerken@xxxxxxxxx>> > > > > > > Since release 5.8-rc1 the pgprot got removed from __vmalloc > > > because the only usage was PAGE_KERNEL as argument. > > > However, this removes the ability to input other arguments > > > such as 'PAGE_KERNEL_EXEC', which can be used to allocate > > > memory in which you can execute. For this reason a new > > > function is introduced called '__vmalloc_exec'. > > > > > > Signed-off-by: Xander Moerkerken <xander.moerkerken@xxxxxxxxx > > <mailto:xander.moerkerken@xxxxxxxxx>> > > > > What is this going to be used for? There's no user from this patch > > alone, as a > > module or otherwise. > > > > Mark. > > > > > --- > > > include/linux/vmalloc.h | 1 + > > > mm/vmalloc.c | 8 ++++++++ > > > 2 files changed, 9 insertions(+) > > > > > > diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h > > > index 096d48aa3437..10c46513b6b2 100644 > > > --- a/include/linux/vmalloc.h > > > +++ b/include/linux/vmalloc.h > > > @@ -147,6 +147,7 @@ extern void *vzalloc_node(unsigned long size, > > int node) __alloc_size(1); > > > extern void *vmalloc_32(unsigned long size) __alloc_size(1); > > > extern void *vmalloc_32_user(unsigned long size) __alloc_size(1); > > > extern void *__vmalloc(unsigned long size, gfp_t gfp_mask) > > __alloc_size(1); > > > +extern void *__vmalloc_exec(unsigned long size, gfp_t gfp_mask) > > __alloc_size(1); > > > extern void *__vmalloc_node_range(unsigned long size, unsigned > > long align, > > > unsigned long start, unsigned long end, > > gfp_t gfp_mask, > > > pgprot_t prot, unsigned long vm_flags, int > > node, > > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > > > index ccaa461998f3..8fd01ed7082b 100644 > > > --- a/mm/vmalloc.c > > > +++ b/mm/vmalloc.c > > > @@ -3294,6 +3294,14 @@ void *__vmalloc(unsigned long size, gfp_t > > gfp_mask) > > > } > > > EXPORT_SYMBOL(__vmalloc); > > > > > > + > > > +void *__vmalloc_exec(unsigned long size, gfp_t gfp_mask) > > > +{ > > > + return __vmalloc_node_prot(size, 1, gfp_mask, PAGE_KERNEL_EXEC, > > > + NUMA_NO_NODE, > > __builtin_return_address(0)); > > > +} > > > +EXPORT_SYMBOL(__vmalloc_exec); > > > + > > > /** > > > * vmalloc - allocate virtually contiguous memory > > > * @size: allocation size > > > -- > > > 2.37.2 > > > > >
