Re: [PATCH 6.1.y v2 3/4] mm: refactor arch_calc_vm_flag_bits() and arm64 MTE handling

Hi Sasha,

On 19/11/24 10:06, Sasha Levin wrote:

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: 5baf8b037debf4ec60108ccfeccb8636d1dbad81

Nice bot!

Just few thoughts:

Commit in newer trees:

|-----------------|----------------------------------------------| | 6.11.y | Present (different SHA1: 9f5efc1137ba) | | 6.6.y | Not found | | 6.1.y | Not found | |-----------------|----------------------------------------------|

Given that this patch is for 6.1.y, it(6.1.y) need not be considered as newer tree I think ?

Also the backport for 6.6.y is present on lore.stable [1], so the backport not being present in stable-6.6.y might be not very useful, as it is possible for people to send the backport to multiple trees in the same stable update cycle(before 6.6.y has the backport included) -- instead could we run this while queuing up(maybe warn if it is neither present in stable-queue-6.6 nor in stable-6.6.y ?) ?

[1] https://lore.kernel.org/all/7c0218d03fd2119025d8cbc1b814639cf09314e0.1731672...

Thanks, Harshit

Note: The patch differs from the upstream commit:

--- - 2024-11-18 17:15:02.588328592 -0500 +++ /tmp/tmp.LhvhUpwE7J 2024-11-18 17:15:02.577003940 -0500 @@ -50,29 +50,29 @@ Cc: Will Deacon will@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org

+Signed-off-by: Lorenzo Stoakes lorenzo.stoakes@oracle.com

• arch/arm64/include/asm/mman.h | 10 +++++++---
• arch/parisc/include/asm/mman.h | 5 +++--
• include/linux/mman.h | 7 ++++---
• mm/mmap.c | 2 +-
• mm/nommu.c | 2 +-
• mm/shmem.c | 3 ---
• 6 files changed, 16 insertions(+), 13 deletions(-)

• arch/arm64/include/asm/mman.h | 10 +++++++---
• include/linux/mman.h | 7 ++++---
• mm/mmap.c | 2 +-
• mm/nommu.c | 2 +-
• mm/shmem.c | 3 ---
• 5 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/arch/arm64/include/asm/mman.h b/arch/arm64/include/asm/mman.h -index 9e39217b4afbb..798d965760d43 100644 +index 5966ee4a6154..ef35c52aabd6 100644 --- a/arch/arm64/include/asm/mman.h +++ b/arch/arm64/include/asm/mman.h -@@ -6,6 +6,8 @@ +@@ -3,6 +3,8 @@

• #define __ASM_MMAN_H__

• #ifndef BUILD_VDSO #include <linux/compiler.h> +#include <linux/fs.h> +#include <linux/shmem_fs.h> #include <linux/types.h>

• #include <uapi/asm/mman.h>

• static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,

-@@ -31,19 +33,21 @@ static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot, +@@ -21,19 +23,21 @@ static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot, } #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey) @@ -97,37 +97,8 @@ static inline bool arch_validate_prot(unsigned long prot, unsigned long addr __always_unused) -diff --git a/arch/parisc/include/asm/mman.h b/arch/parisc/include/asm/mman.h -index 89b6beeda0b86..663f587dc7896 100644 ---- a/arch/parisc/include/asm/mman.h -+++ b/arch/parisc/include/asm/mman.h -@@ -2,6 +2,7 @@

• #ifndef __ASM_MMAN_H__
• #define __ASM_MMAN_H__

-+#include <linux/fs.h>

• #include <uapi/asm/mman.h>
• /* PARISC cannot allow mdwe as it needs writable stacks */

-@@ -11,7 +12,7 @@ static inline bool arch_memory_deny_write_exec_supported(void)

• }
• #define arch_memory_deny_write_exec_supported arch_memory_deny_write_exec_supported

--static inline unsigned long arch_calc_vm_flag_bits(unsigned long flags) -+static inline unsigned long arch_calc_vm_flag_bits(struct file *file, unsigned long flags)

• {
• /*

• * The stack on parisc grows upwards, so if userspace requests memory
  

-@@ -23,6 +24,6 @@ static inline unsigned long arch_calc_vm_flag_bits(unsigned long flags)

• return 0;
• }

--#define arch_calc_vm_flag_bits(flags) arch_calc_vm_flag_bits(flags) -+#define arch_calc_vm_flag_bits(file, flags) arch_calc_vm_flag_bits(file, flags)

• #endif /* __ASM_MMAN_H__ */ diff --git a/include/linux/mman.h b/include/linux/mman.h

-index 8ddca62d6460b..a842783ffa62b 100644 +index 58b3abd457a3..21ea08b919d9 100644 --- a/include/linux/mman.h +++ b/include/linux/mman.h @@ -2,6 +2,7 @@ @@ -138,7 +109,7 @@ #include <linux/mm.h> #include <linux/percpu_counter.h> -@@ -94,7 +95,7 @@ static inline void vm_unacct_memory(long pages) +@@ -90,7 +91,7 @@ static inline void vm_unacct_memory(long pages) #endif #ifndef arch_calc_vm_flag_bits @@ -147,7 +118,7 @@ #endif #ifndef arch_validate_prot -@@ -151,13 +152,13 @@ calc_vm_prot_bits(unsigned long prot, unsigned long pkey) +@@ -147,12 +148,12 @@ calc_vm_prot_bits(unsigned long prot, unsigned long pkey) * Combine the mmap "flags" argument into "vm_flags" used internally. */ static inline unsigned long @@ -157,49 +128,51 @@ return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) | _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) | _calc_vm_trans(flags, MAP_SYNC, VM_SYNC ) |

•       _calc_vm_trans(flags, MAP_STACK,	     VM_NOHUGEPAGE) |
  

  •       arch_calc_vm_flag_bits(flags);
    

  •       arch_calc_vm_flag_bits(file, flags);
    

  } unsigned long vm_commit_limit(void); diff --git a/mm/mmap.c b/mm/mmap.c

-index ab71d4c3464cd..aee5fa08ae5d1 100644 +index 4bfec4df51c2..322677f61d30 100644 --- a/mm/mmap.c +++ b/mm/mmap.c -@@ -344,7 +344,7 @@ unsigned long do_mmap(struct file *file, unsigned long addr, +@@ -1316,7 +1316,7 @@ unsigned long do_mmap(struct file *file, unsigned long addr, * to. we assume access permissions have been handled by the open * of the memory object, so we don't do any here. */ -- vm_flags |= calc_vm_prot_bits(prot, pkey) | calc_vm_flag_bits(flags) | -+ vm_flags |= calc_vm_prot_bits(prot, pkey) | calc_vm_flag_bits(file, flags) | +- vm_flags = calc_vm_prot_bits(prot, pkey) | calc_vm_flag_bits(flags) | ++ vm_flags = calc_vm_prot_bits(prot, pkey) | calc_vm_flag_bits(file, flags) | mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;

• /* Obtain the address to map to. we verify (or select) it and ensure

• if (flags & MAP_LOCKED) diff --git a/mm/nommu.c b/mm/nommu.c

-index 635d028d647b3..e9b5f527ab5b4 100644 +index e0428fa57526..859ba6bdeb9c 100644 --- a/mm/nommu.c +++ b/mm/nommu.c -@@ -842,7 +842,7 @@ static unsigned long determine_vm_flags(struct file *file, +@@ -903,7 +903,7 @@ static unsigned long determine_vm_flags(struct file *file, { unsigned long vm_flags;

• vm_flags = calc_vm_prot_bits(prot, 0) | calc_vm_flag_bits(flags);

• vm_flags = calc_vm_prot_bits(prot, 0) | calc_vm_flag_bits(file, flags);
• /* vm_flags |= mm->def_flags; */

• if (!file) {

• /*
  

• if (!(capabilities & NOMMU_MAP_DIRECT)) { diff --git a/mm/shmem.c b/mm/shmem.c

-index 4ba1d00fabdaa..e87f5d6799a7b 100644 +index 0e1fbc53717d..d1a33f66cc7f 100644 --- a/mm/shmem.c +++ b/mm/shmem.c -@@ -2733,9 +2733,6 @@ static int shmem_mmap(struct file *file, struct vm_area_struct *vma) +@@ -2308,9 +2308,6 @@ static int shmem_mmap(struct file *file, struct vm_area_struct *vma) if (ret) return ret;

• /* arm64 - allow memory tagging on RAM-based files */

-- vm_flags_set(vma, VM_MTE_ALLOWED); +- vma->vm_flags |= VM_MTE_ALLOWED;

• file_accessed(file);
• /* This is anonymous shared memory if it is unlinked at the time of mmap */
• if (inode->i_nlink)

• vma->vm_ops = &shmem_vm_ops;
• return 0;

+-- +2.47.0

---

Results of testing on various branches:

| Branch | Patch Apply | Build Test | |---------------------------|-------------|------------| | stable/linux-6.1.y | Success | Success |