public inbox for stable@vger.kernel.org
 help / color / mirror / Atom feed
* [PATCH V3 1/4] riscv: mm: Fixup compat mode boot failure
       [not found] <20231222115703.2404036-1-guoren@kernel.org>
@ 2023-12-22 11:57 ` guoren
  2023-12-23  2:57   ` Leonardo Bras
  2023-12-22 11:57 ` [PATCH V3 2/4] riscv: mm: Fixup compat arch_get_mmap_end guoren
  1 sibling, 1 reply; 7+ messages in thread
From: guoren @ 2023-12-22 11:57 UTC (permalink / raw)
  To: linux-kernel, paul.walmsley, palmer, alexghiti, charlie,
	xiao.w.wang, guoren, david, panqinglin2020, rick.p.edgecombe,
	willy, bjorn, conor.dooley, cleger, leobras
  Cc: linux-riscv, Guo Ren, stable

From: Guo Ren <guoren@linux.alibaba.com>

In COMPAT mode, the STACK_TOP is DEFAULT_MAP_WINDOW (0x80000000), but
the TASK_SIZE is 0x7fff000. When the user stack is upon 0x7fff000, it
will cause a user segment fault. Sometimes, it would cause boot
failure when the whole rootfs is rv32.

Freeing unused kernel image (initmem) memory: 2236K
Run /sbin/init as init process
Starting init: /sbin/init exists but couldn't execute it (error -14)
Run /etc/init as init process
...

Increase the TASK_SIZE to cover STACK_TOP.

Cc: stable@vger.kernel.org
Fixes: add2cc6b6515 ("RISC-V: mm: Restrict address space for sv39,sv48,sv57")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
---
 arch/riscv/include/asm/pgtable.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index ab00235b018f..74ffb2178f54 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -881,7 +881,7 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte)
 #define TASK_SIZE_MIN	(PGDIR_SIZE_L3 * PTRS_PER_PGD / 2)
 
 #ifdef CONFIG_COMPAT
-#define TASK_SIZE_32	(_AC(0x80000000, UL) - PAGE_SIZE)
+#define TASK_SIZE_32	(_AC(0x80000000, UL))
 #define TASK_SIZE	(test_thread_flag(TIF_32BIT) ? \
 			 TASK_SIZE_32 : TASK_SIZE_64)
 #else
-- 
2.40.1


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* [PATCH V3 2/4] riscv: mm: Fixup compat arch_get_mmap_end
       [not found] <20231222115703.2404036-1-guoren@kernel.org>
  2023-12-22 11:57 ` [PATCH V3 1/4] riscv: mm: Fixup compat mode boot failure guoren
@ 2023-12-22 11:57 ` guoren
  2023-12-23  2:51   ` Leonardo Bras
  1 sibling, 1 reply; 7+ messages in thread
From: guoren @ 2023-12-22 11:57 UTC (permalink / raw)
  To: linux-kernel, paul.walmsley, palmer, alexghiti, charlie,
	xiao.w.wang, guoren, david, panqinglin2020, rick.p.edgecombe,
	willy, bjorn, conor.dooley, cleger, leobras
  Cc: linux-riscv, Guo Ren, stable

From: Guo Ren <guoren@linux.alibaba.com>

When the task is in COMPAT mode, the arch_get_mmap_end should be 2GB,
not TASK_SIZE_64. The TASK_SIZE has contained is_compat_mode()
detection, so change the definition of STACK_TOP_MAX to TASK_SIZE
directly.

Cc: stable@vger.kernel.org
Fixes: add2cc6b6515 ("RISC-V: mm: Restrict address space for sv39,sv48,sv57")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
---
 arch/riscv/include/asm/processor.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index f19f861cda54..e1944ff0757a 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -16,7 +16,7 @@
 
 #ifdef CONFIG_64BIT
 #define DEFAULT_MAP_WINDOW	(UL(1) << (MMAP_VA_BITS - 1))
-#define STACK_TOP_MAX		TASK_SIZE_64
+#define STACK_TOP_MAX		TASK_SIZE
 
 #define arch_get_mmap_end(addr, len, flags)			\
 ({								\
-- 
2.40.1


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* Re: [PATCH V3 2/4] riscv: mm: Fixup compat arch_get_mmap_end
  2023-12-22 11:57 ` [PATCH V3 2/4] riscv: mm: Fixup compat arch_get_mmap_end guoren
@ 2023-12-23  2:51   ` Leonardo Bras
  2023-12-23  3:39     ` Charlie Jenkins
  0 siblings, 1 reply; 7+ messages in thread
From: Leonardo Bras @ 2023-12-23  2:51 UTC (permalink / raw)
  To: guoren
  Cc: Leonardo Bras, linux-kernel, paul.walmsley, palmer, alexghiti,
	charlie, xiao.w.wang, david, panqinglin2020, rick.p.edgecombe,
	willy, bjorn, conor.dooley, cleger, linux-riscv, Guo Ren, stable

On Fri, Dec 22, 2023 at 06:57:01AM -0500, guoren@kernel.org wrote:
> From: Guo Ren <guoren@linux.alibaba.com>
> 
> When the task is in COMPAT mode, the arch_get_mmap_end should be 2GB,
> not TASK_SIZE_64. The TASK_SIZE has contained is_compat_mode()
> detection, so change the definition of STACK_TOP_MAX to TASK_SIZE
> directly.
> 
> Cc: stable@vger.kernel.org
> Fixes: add2cc6b6515 ("RISC-V: mm: Restrict address space for sv39,sv48,sv57")
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Signed-off-by: Guo Ren <guoren@kernel.org>
> ---
>  arch/riscv/include/asm/processor.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
> index f19f861cda54..e1944ff0757a 100644
> --- a/arch/riscv/include/asm/processor.h
> +++ b/arch/riscv/include/asm/processor.h
> @@ -16,7 +16,7 @@
>  
>  #ifdef CONFIG_64BIT
>  #define DEFAULT_MAP_WINDOW	(UL(1) << (MMAP_VA_BITS - 1))
> -#define STACK_TOP_MAX		TASK_SIZE_64
> +#define STACK_TOP_MAX		TASK_SIZE
>  
>  #define arch_get_mmap_end(addr, len, flags)			\
>  ({								\
> -- 
> 2.40.1
> 


LGTM. 

FWIW:
Reviewed-by: Leonardo Bras <leobras@redhat.com>


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH V3 1/4] riscv: mm: Fixup compat mode boot failure
  2023-12-22 11:57 ` [PATCH V3 1/4] riscv: mm: Fixup compat mode boot failure guoren
@ 2023-12-23  2:57   ` Leonardo Bras
  2023-12-23  3:07     ` Guo Ren
  0 siblings, 1 reply; 7+ messages in thread
From: Leonardo Bras @ 2023-12-23  2:57 UTC (permalink / raw)
  To: guoren
  Cc: Leonardo Bras, linux-kernel, paul.walmsley, palmer, alexghiti,
	charlie, xiao.w.wang, david, panqinglin2020, rick.p.edgecombe,
	willy, bjorn, conor.dooley, cleger, linux-riscv, Guo Ren, stable

On Fri, Dec 22, 2023 at 06:57:00AM -0500, guoren@kernel.org wrote:
> From: Guo Ren <guoren@linux.alibaba.com>
> 
> In COMPAT mode, the STACK_TOP is DEFAULT_MAP_WINDOW (0x80000000), but
> the TASK_SIZE is 0x7fff000. When the user stack is upon 0x7fff000, it
> will cause a user segment fault. Sometimes, it would cause boot
> failure when the whole rootfs is rv32.
> 
> Freeing unused kernel image (initmem) memory: 2236K
> Run /sbin/init as init process
> Starting init: /sbin/init exists but couldn't execute it (error -14)
> Run /etc/init as init process
> ...
> 
> Increase the TASK_SIZE to cover STACK_TOP.
> 
> Cc: stable@vger.kernel.org
> Fixes: add2cc6b6515 ("RISC-V: mm: Restrict address space for sv39,sv48,sv57")
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Signed-off-by: Guo Ren <guoren@kernel.org>
> ---
>  arch/riscv/include/asm/pgtable.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> index ab00235b018f..74ffb2178f54 100644
> --- a/arch/riscv/include/asm/pgtable.h
> +++ b/arch/riscv/include/asm/pgtable.h
> @@ -881,7 +881,7 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte)
>  #define TASK_SIZE_MIN	(PGDIR_SIZE_L3 * PTRS_PER_PGD / 2)
>  
>  #ifdef CONFIG_COMPAT
> -#define TASK_SIZE_32	(_AC(0x80000000, UL) - PAGE_SIZE)
> +#define TASK_SIZE_32	(_AC(0x80000000, UL))
>  #define TASK_SIZE	(test_thread_flag(TIF_32BIT) ? \
>  			 TASK_SIZE_32 : TASK_SIZE_64)
>  #else
> -- 
> 2.40.1
> 

I am not really involved in the issue this is solving, so I have no 
technical opinion on the solution. 

IIUC there should always be (TASK_SIZE >= STACK_TOP), so by itself this 
is fixing an issue.

I have reviewed the code and it does exactly as stated into the commit 
message, so FWIW:
Reviewed-by: Leonardo Bras <leobras@redhat.com>


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH V3 1/4] riscv: mm: Fixup compat mode boot failure
  2023-12-23  2:57   ` Leonardo Bras
@ 2023-12-23  3:07     ` Guo Ren
  2023-12-23  3:36       ` Charlie Jenkins
  0 siblings, 1 reply; 7+ messages in thread
From: Guo Ren @ 2023-12-23  3:07 UTC (permalink / raw)
  To: Leonardo Bras, charlie
  Cc: linux-kernel, paul.walmsley, palmer, alexghiti, xiao.w.wang,
	david, panqinglin2020, rick.p.edgecombe, willy, bjorn,
	conor.dooley, cleger, linux-riscv, Guo Ren, stable

On Sat, Dec 23, 2023 at 10:58 AM Leonardo Bras <leobras@redhat.com> wrote:
>
> On Fri, Dec 22, 2023 at 06:57:00AM -0500, guoren@kernel.org wrote:
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > In COMPAT mode, the STACK_TOP is DEFAULT_MAP_WINDOW (0x80000000), but
> > the TASK_SIZE is 0x7fff000. When the user stack is upon 0x7fff000, it
> > will cause a user segment fault. Sometimes, it would cause boot
> > failure when the whole rootfs is rv32.
> >
> > Freeing unused kernel image (initmem) memory: 2236K
> > Run /sbin/init as init process
> > Starting init: /sbin/init exists but couldn't execute it (error -14)
> > Run /etc/init as init process
> > ...
> >
> > Increase the TASK_SIZE to cover STACK_TOP.
> >
> > Cc: stable@vger.kernel.org
> > Fixes: add2cc6b6515 ("RISC-V: mm: Restrict address space for sv39,sv48,sv57")
> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> > Signed-off-by: Guo Ren <guoren@kernel.org>
> > ---
> >  arch/riscv/include/asm/pgtable.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> > index ab00235b018f..74ffb2178f54 100644
> > --- a/arch/riscv/include/asm/pgtable.h
> > +++ b/arch/riscv/include/asm/pgtable.h
> > @@ -881,7 +881,7 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte)
> >  #define TASK_SIZE_MIN        (PGDIR_SIZE_L3 * PTRS_PER_PGD / 2)
> >
> >  #ifdef CONFIG_COMPAT
> > -#define TASK_SIZE_32 (_AC(0x80000000, UL) - PAGE_SIZE)
> > +#define TASK_SIZE_32 (_AC(0x80000000, UL))
> >  #define TASK_SIZE    (test_thread_flag(TIF_32BIT) ? \
> >                        TASK_SIZE_32 : TASK_SIZE_64)
> >  #else
> > --
> > 2.40.1
> >
>
> I am not really involved in the issue this is solving, so I have no
> technical opinion on the solution.
>
> IIUC there should always be (TASK_SIZE >= STACK_TOP), so by itself this
> is fixing an issue.
>
> I have reviewed the code and it does exactly as stated into the commit
> message, so FWIW:
> Reviewed-by: Leonardo Bras <leobras@redhat.com>
Thx,

I found this problem because it can't boot my rv32 buildroot-rootfs in
v6.6. But it's okay in v6.5. So I used git bisect and found commit:
add2cc6b6515 ("RISC-V: mm: Restrict address space for
sv39,sv48,sv57"), which caused that.

Ping Charlie, I hope it can be fixed in the v6.6 long-term version.

>



--
Best Regards
 Guo Ren

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH V3 1/4] riscv: mm: Fixup compat mode boot failure
  2023-12-23  3:07     ` Guo Ren
@ 2023-12-23  3:36       ` Charlie Jenkins
  0 siblings, 0 replies; 7+ messages in thread
From: Charlie Jenkins @ 2023-12-23  3:36 UTC (permalink / raw)
  To: Guo Ren
  Cc: Leonardo Bras, linux-kernel, paul.walmsley, palmer, alexghiti,
	xiao.w.wang, david, panqinglin2020, rick.p.edgecombe, willy,
	bjorn, conor.dooley, cleger, linux-riscv, Guo Ren, stable

On Sat, Dec 23, 2023 at 11:07:29AM +0800, Guo Ren wrote:
> On Sat, Dec 23, 2023 at 10:58 AM Leonardo Bras <leobras@redhat.com> wrote:
> >
> > On Fri, Dec 22, 2023 at 06:57:00AM -0500, guoren@kernel.org wrote:
> > > From: Guo Ren <guoren@linux.alibaba.com>
> > >
> > > In COMPAT mode, the STACK_TOP is DEFAULT_MAP_WINDOW (0x80000000), but
> > > the TASK_SIZE is 0x7fff000. When the user stack is upon 0x7fff000, it
> > > will cause a user segment fault. Sometimes, it would cause boot
> > > failure when the whole rootfs is rv32.
> > >
> > > Freeing unused kernel image (initmem) memory: 2236K
> > > Run /sbin/init as init process
> > > Starting init: /sbin/init exists but couldn't execute it (error -14)
> > > Run /etc/init as init process
> > > ...
> > >
> > > Increase the TASK_SIZE to cover STACK_TOP.
> > >
> > > Cc: stable@vger.kernel.org
> > > Fixes: add2cc6b6515 ("RISC-V: mm: Restrict address space for sv39,sv48,sv57")
> > > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> > > Signed-off-by: Guo Ren <guoren@kernel.org>
> > > ---
> > >  arch/riscv/include/asm/pgtable.h | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> > > index ab00235b018f..74ffb2178f54 100644
> > > --- a/arch/riscv/include/asm/pgtable.h
> > > +++ b/arch/riscv/include/asm/pgtable.h
> > > @@ -881,7 +881,7 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte)
> > >  #define TASK_SIZE_MIN        (PGDIR_SIZE_L3 * PTRS_PER_PGD / 2)
> > >
> > >  #ifdef CONFIG_COMPAT
> > > -#define TASK_SIZE_32 (_AC(0x80000000, UL) - PAGE_SIZE)
> > > +#define TASK_SIZE_32 (_AC(0x80000000, UL))
> > >  #define TASK_SIZE    (test_thread_flag(TIF_32BIT) ? \
> > >                        TASK_SIZE_32 : TASK_SIZE_64)
> > >  #else
> > > --
> > > 2.40.1
> > >
> >
> > I am not really involved in the issue this is solving, so I have no
> > technical opinion on the solution.
> >
> > IIUC there should always be (TASK_SIZE >= STACK_TOP), so by itself this
> > is fixing an issue.
> >
> > I have reviewed the code and it does exactly as stated into the commit
> > message, so FWIW:
> > Reviewed-by: Leonardo Bras <leobras@redhat.com>
> Thx,
> 
> I found this problem because it can't boot my rv32 buildroot-rootfs in
> v6.6. But it's okay in v6.5. So I used git bisect and found commit:
> add2cc6b6515 ("RISC-V: mm: Restrict address space for
> sv39,sv48,sv57"), which caused that.
> 
> Ping Charlie, I hope it can be fixed in the v6.6 long-term version.

I have looked at this more I do agree that this change makes sense. I
was thinking that it was valid to have STACK_TOP that was greater than
TASK_SIZE but I am no longer convinced that is true. Thank you for
looking into this.

Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>

> 
> >
> 
> 
> 
> --
> Best Regards
>  Guo Ren

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH V3 2/4] riscv: mm: Fixup compat arch_get_mmap_end
  2023-12-23  2:51   ` Leonardo Bras
@ 2023-12-23  3:39     ` Charlie Jenkins
  0 siblings, 0 replies; 7+ messages in thread
From: Charlie Jenkins @ 2023-12-23  3:39 UTC (permalink / raw)
  To: Leonardo Bras
  Cc: guoren, linux-kernel, paul.walmsley, palmer, alexghiti,
	xiao.w.wang, david, panqinglin2020, rick.p.edgecombe, willy,
	bjorn, conor.dooley, cleger, linux-riscv, Guo Ren, stable

On Fri, Dec 22, 2023 at 11:51:48PM -0300, Leonardo Bras wrote:
> On Fri, Dec 22, 2023 at 06:57:01AM -0500, guoren@kernel.org wrote:
> > From: Guo Ren <guoren@linux.alibaba.com>
> > 
> > When the task is in COMPAT mode, the arch_get_mmap_end should be 2GB,
> > not TASK_SIZE_64. The TASK_SIZE has contained is_compat_mode()
> > detection, so change the definition of STACK_TOP_MAX to TASK_SIZE
> > directly.
> > 
> > Cc: stable@vger.kernel.org
> > Fixes: add2cc6b6515 ("RISC-V: mm: Restrict address space for sv39,sv48,sv57")
> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> > Signed-off-by: Guo Ren <guoren@kernel.org>
> > ---
> >  arch/riscv/include/asm/processor.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
> > index f19f861cda54..e1944ff0757a 100644
> > --- a/arch/riscv/include/asm/processor.h
> > +++ b/arch/riscv/include/asm/processor.h
> > @@ -16,7 +16,7 @@
> >  
> >  #ifdef CONFIG_64BIT
> >  #define DEFAULT_MAP_WINDOW	(UL(1) << (MMAP_VA_BITS - 1))
> > -#define STACK_TOP_MAX		TASK_SIZE_64
> > +#define STACK_TOP_MAX		TASK_SIZE
> >  
> >  #define arch_get_mmap_end(addr, len, flags)			\
> >  ({								\
> > -- 
> > 2.40.1
> > 
> 
> 
> LGTM. 
> 
> FWIW:
> Reviewed-by: Leonardo Bras <leobras@redhat.com>

Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>

> 

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2023-12-23  3:39 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
     [not found] <20231222115703.2404036-1-guoren@kernel.org>
2023-12-22 11:57 ` [PATCH V3 1/4] riscv: mm: Fixup compat mode boot failure guoren
2023-12-23  2:57   ` Leonardo Bras
2023-12-23  3:07     ` Guo Ren
2023-12-23  3:36       ` Charlie Jenkins
2023-12-22 11:57 ` [PATCH V3 2/4] riscv: mm: Fixup compat arch_get_mmap_end guoren
2023-12-23  2:51   ` Leonardo Bras
2023-12-23  3:39     ` Charlie Jenkins

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox