| Message ID | 1529532570-21765-2-git-send-email-rick.p.edgecombe@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 06/20/2018 03:09 PM, Rick Edgecombe wrote: > Create __vmalloc_node_try_addr function that tries to allocate at a specific > address. The implementation relies on __vmalloc_node_range for the bulk of the > work. To keep this function from spamming the logs when an allocation failure > is fails, __vmalloc_node_range is changed to only warn when __GFP_NOWARN is not > set. This behavior is consistent with this flags interpretation in > alloc_vmap_area. > > Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> > --- > include/linux/vmalloc.h | 3 +++ > mm/vmalloc.c | 41 +++++++++++++++++++++++++++++++++++++++-- > 2 files changed, 42 insertions(+), 2 deletions(-) > > diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h > index 398e9c9..6eaa896 100644 > --- a/include/linux/vmalloc.h > +++ b/include/linux/vmalloc.h > @@ -82,6 +82,9 @@ 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, > const void *caller); > +extern void *__vmalloc_node_try_addr(unsigned long addr, unsigned long size, > + gfp_t gfp_mask, pgprot_t prot, unsigned long vm_flags, > + int node, const void *caller); > #ifndef CONFIG_MMU > extern void *__vmalloc_node_flags(unsigned long size, int node, gfp_t flags); > static inline void *__vmalloc_node_flags_caller(unsigned long size, int node, > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index cfea25b..9e0820c9 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -1710,6 +1710,42 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, > } > > /** > + * __vmalloc_try_addr - try to alloc at a specific address * __vmalloc_node_try_addr - try to allocate at a specific address > + * @addr: address to try > + * @size: size to try > + * @gfp_mask: flags for the page level allocator > + * @prot: protection mask for the allocated pages > + * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD) > + * @node: node to use for allocation or NUMA_NO_NODE > + * @caller: caller's return address > + * > + * Try to allocate at the specific address. If it succeeds the address is > + * returned. If it fails NULL is returned. It may trigger TLB flushes. > + */ > +void *__vmalloc_node_try_addr(unsigned long addr, unsigned long size, > + gfp_t gfp_mask, pgprot_t prot, unsigned long vm_flags, > + int node, const void *caller) > +{ so this isn't optional, eh? You are going to force it on people because? thanks,
On Wed, Jun 20, 2018 at 03:09:28PM -0700, Rick Edgecombe wrote: > > /** > + * __vmalloc_try_addr - try to alloc at a specific address > + * @addr: address to try > + * @size: size to try > + * @gfp_mask: flags for the page level allocator > + * @prot: protection mask for the allocated pages > + * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD) > + * @node: node to use for allocation or NUMA_NO_NODE > + * @caller: caller's return address > + * > + * Try to allocate at the specific address. If it succeeds the address is > + * returned. If it fails NULL is returned. It may trigger TLB flushes. * Try to allocate memory at a specific address. May trigger TLB flushes. * * Context: Process context. * Return: The allocated address if it succeeds. NULL if it fails. > @@ -1759,8 +1795,9 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, > return addr; > > fail: > - warn_alloc(gfp_mask, NULL, > - "vmalloc: allocation failure: %lu bytes", real_size); > + if (!(gfp_mask & __GFP_NOWARN)) > + warn_alloc(gfp_mask, NULL, > + "vmalloc: allocation failure: %lu bytes", real_size); > return NULL; Not needed: void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...) { ... if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs)) return;
On Wed, Jun 20, 2018 at 3:16 PM, Randy Dunlap <rdunlap@infradead.org> wrote: > On 06/20/2018 03:09 PM, Rick Edgecombe wrote: >> +void *__vmalloc_node_try_addr(unsigned long addr, unsigned long size, >> + gfp_t gfp_mask, pgprot_t prot, unsigned long vm_flags, >> + int node, const void *caller) >> +{ > > so this isn't optional, eh? You are going to force it on people because? RANDOMIZE_BASE isn't optional either. :) This improves the module address entropy with (what seems to be) no down-side, so yeah, I think it should be non-optional. :) -Kees
On 06/20/2018 03:35 PM, Kees Cook wrote: > On Wed, Jun 20, 2018 at 3:16 PM, Randy Dunlap <rdunlap@infradead.org> wrote: >> On 06/20/2018 03:09 PM, Rick Edgecombe wrote: >>> +void *__vmalloc_node_try_addr(unsigned long addr, unsigned long size, >>> + gfp_t gfp_mask, pgprot_t prot, unsigned long vm_flags, >>> + int node, const void *caller) >>> +{ >> >> so this isn't optional, eh? You are going to force it on people because? > > RANDOMIZE_BASE isn't optional either. :) This improves the module > address entropy with (what seems to be) no down-side, so yeah, I think > it should be non-optional. :) In what kernel tree is RANDOMIZE_BASE not optional? x86: config RANDOMIZE_BASE bool "Randomize the address of the kernel image (KASLR)" depends on RELOCATABLE default y mips: config RANDOMIZE_BASE bool "Randomize the address of the kernel image" depends on RELOCATABLE arm64: config RANDOMIZE_BASE bool "Randomize the address of the kernel image" select ARM64_MODULE_PLTS if MODULES select RELOCATABLE thanks,
On Wed, Jun 20, 2018 at 3:44 PM, Randy Dunlap <rdunlap@infradead.org> wrote: > On 06/20/2018 03:35 PM, Kees Cook wrote: >> On Wed, Jun 20, 2018 at 3:16 PM, Randy Dunlap <rdunlap@infradead.org> wrote: >>> On 06/20/2018 03:09 PM, Rick Edgecombe wrote: >>>> +void *__vmalloc_node_try_addr(unsigned long addr, unsigned long size, >>>> + gfp_t gfp_mask, pgprot_t prot, unsigned long vm_flags, >>>> + int node, const void *caller) >>>> +{ >>> >>> so this isn't optional, eh? You are going to force it on people because? >> >> RANDOMIZE_BASE isn't optional either. :) This improves the module >> address entropy with (what seems to be) no down-side, so yeah, I think >> it should be non-optional. :) > > In what kernel tree is RANDOMIZE_BASE not optional? Oh, sorry, I misspoke: on by default. It _is_ possible to turn it off. But patch #2 does check for RANDOMIZE_BASE, so it should work as expected, yes? Or did you want even this helper function to be compiled out without it? -Kees
On 06/20/2018 04:05 PM, Kees Cook wrote: > On Wed, Jun 20, 2018 at 3:44 PM, Randy Dunlap <rdunlap@infradead.org> wrote: >> On 06/20/2018 03:35 PM, Kees Cook wrote: >>> On Wed, Jun 20, 2018 at 3:16 PM, Randy Dunlap <rdunlap@infradead.org> wrote: >>>> On 06/20/2018 03:09 PM, Rick Edgecombe wrote: >>>>> +void *__vmalloc_node_try_addr(unsigned long addr, unsigned long size, >>>>> + gfp_t gfp_mask, pgprot_t prot, unsigned long vm_flags, >>>>> + int node, const void *caller) >>>>> +{ >>>> >>>> so this isn't optional, eh? You are going to force it on people because? >>> >>> RANDOMIZE_BASE isn't optional either. :) This improves the module >>> address entropy with (what seems to be) no down-side, so yeah, I think >>> it should be non-optional. :) >> >> In what kernel tree is RANDOMIZE_BASE not optional? > > Oh, sorry, I misspoke: on by default. It _is_ possible to turn it off. > > But patch #2 does check for RANDOMIZE_BASE, so it should work as expected, yes? > > Or did you want even this helper function to be compiled out without it? Thanks, I missed it. :( Looks fine.
On Wed, 2018-06-20 at 15:26 -0700, Matthew Wilcox wrote: > Not needed: > > void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char > *fmt, ...) > { > ... > if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs)) > return; > Yes, thanks!
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 398e9c9..6eaa896 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -82,6 +82,9 @@ 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, const void *caller); +extern void *__vmalloc_node_try_addr(unsigned long addr, unsigned long size, + gfp_t gfp_mask, pgprot_t prot, unsigned long vm_flags, + int node, const void *caller); #ifndef CONFIG_MMU extern void *__vmalloc_node_flags(unsigned long size, int node, gfp_t flags); static inline void *__vmalloc_node_flags_caller(unsigned long size, int node, diff --git a/mm/vmalloc.c b/mm/vmalloc.c index cfea25b..9e0820c9 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1710,6 +1710,42 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, } /** + * __vmalloc_try_addr - try to alloc at a specific address + * @addr: address to try + * @size: size to try + * @gfp_mask: flags for the page level allocator + * @prot: protection mask for the allocated pages + * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD) + * @node: node to use for allocation or NUMA_NO_NODE + * @caller: caller's return address + * + * Try to allocate at the specific address. If it succeeds the address is + * returned. If it fails NULL is returned. It may trigger TLB flushes. + */ +void *__vmalloc_node_try_addr(unsigned long addr, unsigned long size, + gfp_t gfp_mask, pgprot_t prot, unsigned long vm_flags, + int node, const void *caller) +{ + unsigned long addr_end; + unsigned long vsize = PAGE_ALIGN(size); + + if (!vsize || (vsize >> PAGE_SHIFT) > totalram_pages) + return NULL; + + if (!(vm_flags & VM_NO_GUARD)) + vsize += PAGE_SIZE; + + addr_end = addr + vsize; + + if (addr > addr_end) + return NULL; + + return __vmalloc_node_range(size, 1, addr, addr_end, + gfp_mask | __GFP_NOWARN, prot, vm_flags, node, + caller); +} + +/** * __vmalloc_node_range - allocate virtually contiguous memory * @size: allocation size * @align: desired alignment @@ -1759,8 +1795,9 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, return addr; fail: - warn_alloc(gfp_mask, NULL, - "vmalloc: allocation failure: %lu bytes", real_size); + if (!(gfp_mask & __GFP_NOWARN)) + warn_alloc(gfp_mask, NULL, + "vmalloc: allocation failure: %lu bytes", real_size); return NULL; }
Create __vmalloc_node_try_addr function that tries to allocate at a specific address. The implementation relies on __vmalloc_node_range for the bulk of the work. To keep this function from spamming the logs when an allocation failure is fails, __vmalloc_node_range is changed to only warn when __GFP_NOWARN is not set. This behavior is consistent with this flags interpretation in alloc_vmap_area. Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> --- include/linux/vmalloc.h | 3 +++ mm/vmalloc.c | 41 +++++++++++++++++++++++++++++++++++++++-- 2 files changed, 42 insertions(+), 2 deletions(-)