2020-06-28 16:12:13

by Guo Ren

Subject: [PATCH V2] riscv: Fixup compile error BUILD_BUG_ON failed

From: Guo Ren <[email protected]>

Unfortunately, the current code couldn't be compiled:

CC arch/riscv/kernel/patch.o
In file included from ./include/linux/kernel.h:11,
from ./include/linux/list.h:9,
from ./include/linux/preempt.h:11,
from ./include/linux/spinlock.h:51,
from arch/riscv/kernel/patch.c:6:
In function ‘fix_to_virt’,
inlined from ‘patch_map’ at arch/riscv/kernel/patch.c:37:17:
./include/linux/compiler.h:392:38: error: call to ‘__compiletime_assert_205’ declared with attribute error: BUILD_BUG_ON failed: idx >= __end_of_fixed_addresses
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
^
./include/linux/compiler.h:373:4: note: in definition of macro ‘__compiletime_assert’
prefix ## suffix(); \
^~~~~~
./include/linux/compiler.h:392:2: note: in expansion of macro ‘_compiletime_assert’
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
^~~~~~~~~~~~~~~~~~~
./include/linux/build_bug.h:39:37: note: in expansion of macro ‘compiletime_assert’
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
^~~~~~~~~~~~~~~~~~
./include/linux/build_bug.h:50:2: note: in expansion of macro ‘BUILD_BUG_ON_MSG’
BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
^~~~~~~~~~~~~~~~
./include/asm-generic/fixmap.h:32:2: note: in expansion of macro ‘BUILD_BUG_ON’
BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
^~~~~~~~~~~~

Because fix_to_virt(, idx) needs a const value, not a dynamic variable of
reg-a0 or BUILD_BUG_ON failed with "idx >= __end_of_fixed_addresses".

Signed-off-by: Guo Ren <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Zong Li <[email protected]>
---
Changelog V2:
- Use __always_inline as same as fix_to_virt
- Use const "const unsigned int" for 2th param

Signed-off-by: Guo Ren <[email protected]>
---
arch/riscv/kernel/patch.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c
index d4a64df..3179a4e 100644
--- a/arch/riscv/kernel/patch.c
+++ b/arch/riscv/kernel/patch.c
@@ -20,7 +20,12 @@ struct patch_insn {
};

#ifdef CONFIG_MMU
-static void *patch_map(void *addr, int fixmap)
+/*
+ * The fix_to_virt(, idx) needs a const value (not a dynamic variable of
+ * reg-a0) or BUILD_BUG_ON failed with "idx >= __end_of_fixed_addresses".
+ * So use '__always_inline' and 'const unsigned int fixmap' here.
+ */
+static __always_inline void *patch_map(void *addr, const unsigned int fixmap)
{
uintptr_t uintaddr = (uintptr_t) addr;
struct page *page;
@@ -37,7 +42,6 @@ static void *patch_map(void *addr, int fixmap)
return (void *)set_fixmap_offset(fixmap, page_to_phys(page) +
(uintaddr & ~PAGE_MASK));
}
-NOKPROBE_SYMBOL(patch_map);

static void patch_unmap(int fixmap)
{
--
2.7.4

2020-06-28 16:28:00

by Masami Hiramatsu

Subject: Re: [PATCH V2] riscv: Fixup compile error BUILD_BUG_ON failed

On Sun, 28 Jun 2020 16:07:37 +0000
[email protected] wrote:

> From: Guo Ren <[email protected]>
>
> Unfortunately, the current code couldn't be compiled:
>
> CC arch/riscv/kernel/patch.o
> In file included from ./include/linux/kernel.h:11,
> from ./include/linux/list.h:9,
> from ./include/linux/preempt.h:11,
> from ./include/linux/spinlock.h:51,
> from arch/riscv/kernel/patch.c:6:
> In function ‘fix_to_virt’,
> inlined from ‘patch_map’ at arch/riscv/kernel/patch.c:37:17:
> ./include/linux/compiler.h:392:38: error: call to ‘__compiletime_assert_205’ declared with attribute error: BUILD_BUG_ON failed: idx >= __end_of_fixed_addresses
> _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
> ^
> ./include/linux/compiler.h:373:4: note: in definition of macro ‘__compiletime_assert’
> prefix ## suffix(); \
> ^~~~~~
> ./include/linux/compiler.h:392:2: note: in expansion of macro ‘_compiletime_assert’
> _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
> ^~~~~~~~~~~~~~~~~~~
> ./include/linux/build_bug.h:39:37: note: in expansion of macro ‘compiletime_assert’
> #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
> ^~~~~~~~~~~~~~~~~~
> ./include/linux/build_bug.h:50:2: note: in expansion of macro ‘BUILD_BUG_ON_MSG’
> BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
> ^~~~~~~~~~~~~~~~
> ./include/asm-generic/fixmap.h:32:2: note: in expansion of macro ‘BUILD_BUG_ON’
> BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
> ^~~~~~~~~~~~
>
> Because fix_to_virt(, idx) needs a const value, not a dynamic variable of
> reg-a0 or BUILD_BUG_ON failed with "idx >= __end_of_fixed_addresses".

Looks good to me :)

Reviewed-by: Masami Hiramatsu <[email protected]>

Thanks!

>
> Signed-off-by: Guo Ren <[email protected]>
> Cc: Masami Hiramatsu <[email protected]>
> Cc: Zong Li <[email protected]>
> ---
> Changelog V2:
> - Use __always_inline as same as fix_to_virt
> - Use const "const unsigned int" for 2th param
>
> Signed-off-by: Guo Ren <[email protected]>
> ---
> arch/riscv/kernel/patch.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c
> index d4a64df..3179a4e 100644
> --- a/arch/riscv/kernel/patch.c
> +++ b/arch/riscv/kernel/patch.c
> @@ -20,7 +20,12 @@ struct patch_insn {
> };
>
> #ifdef CONFIG_MMU
> -static void *patch_map(void *addr, int fixmap)
> +/*
> + * The fix_to_virt(, idx) needs a const value (not a dynamic variable of
> + * reg-a0) or BUILD_BUG_ON failed with "idx >= __end_of_fixed_addresses".
> + * So use '__always_inline' and 'const unsigned int fixmap' here.
> + */
> +static __always_inline void *patch_map(void *addr, const unsigned int fixmap)
> {
> uintptr_t uintaddr = (uintptr_t) addr;
> struct page *page;
> @@ -37,7 +42,6 @@ static void *patch_map(void *addr, int fixmap)
> return (void *)set_fixmap_offset(fixmap, page_to_phys(page) +
> (uintaddr & ~PAGE_MASK));
> }
> -NOKPROBE_SYMBOL(patch_map);
>
> static void patch_unmap(int fixmap)
> {
> --
> 2.7.4
>


--
Masami Hiramatsu <[email protected]>

2020-06-29 23:23:48

by Palmer Dabbelt

Subject: Re: [PATCH V2] riscv: Fixup compile error BUILD_BUG_ON failed

On Sun, 28 Jun 2020 09:25:24 PDT (-0700), [email protected] wrote:
> On Sun, 28 Jun 2020 16:07:37 +0000
> [email protected] wrote:
>
>> From: Guo Ren <[email protected]>
>>
>> Unfortunately, the current code couldn't be compiled:
>>
>> CC arch/riscv/kernel/patch.o
>> In file included from ./include/linux/kernel.h:11,
>> from ./include/linux/list.h:9,
>> from ./include/linux/preempt.h:11,
>> from ./include/linux/spinlock.h:51,
>> from arch/riscv/kernel/patch.c:6:
>> In function ‘fix_to_virt’,
>> inlined from ‘patch_map’ at arch/riscv/kernel/patch.c:37:17:
>> ./include/linux/compiler.h:392:38: error: call to ‘__compiletime_assert_205’ declared with attribute error: BUILD_BUG_ON failed: idx >= __end_of_fixed_addresses
>> _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
>> ^
>> ./include/linux/compiler.h:373:4: note: in definition of macro ‘__compiletime_assert’
>> prefix ## suffix(); \
>> ^~~~~~
>> ./include/linux/compiler.h:392:2: note: in expansion of macro ‘_compiletime_assert’
>> _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
>> ^~~~~~~~~~~~~~~~~~~
>> ./include/linux/build_bug.h:39:37: note: in expansion of macro ‘compiletime_assert’
>> #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
>> ^~~~~~~~~~~~~~~~~~
>> ./include/linux/build_bug.h:50:2: note: in expansion of macro ‘BUILD_BUG_ON_MSG’
>> BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
>> ^~~~~~~~~~~~~~~~
>> ./include/asm-generic/fixmap.h:32:2: note: in expansion of macro ‘BUILD_BUG_ON’
>> BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
>> ^~~~~~~~~~~~
>>
>> Because fix_to_virt(, idx) needs a const value, not a dynamic variable of
>> reg-a0 or BUILD_BUG_ON failed with "idx >= __end_of_fixed_addresses".
>
> Looks good to me :)
>
> Reviewed-by: Masami Hiramatsu <[email protected]>

Is there a configuration that runs into this bug? It's not showing up for me,
and I generally try to add regressions to my test suite.

> Thanks!
>
>>
>> Signed-off-by: Guo Ren <[email protected]>
>> Cc: Masami Hiramatsu <[email protected]>
>> Cc: Zong Li <[email protected]>
>> ---
>> Changelog V2:
>> - Use __always_inline as same as fix_to_virt
>> - Use const "const unsigned int" for 2th param
>>
>> Signed-off-by: Guo Ren <[email protected]>
>> ---
>> arch/riscv/kernel/patch.c | 8 ++++++--
>> 1 file changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c
>> index d4a64df..3179a4e 100644
>> --- a/arch/riscv/kernel/patch.c
>> +++ b/arch/riscv/kernel/patch.c
>> @@ -20,7 +20,12 @@ struct patch_insn {
>> };
>>
>> #ifdef CONFIG_MMU
>> -static void *patch_map(void *addr, int fixmap)
>> +/*
>> + * The fix_to_virt(, idx) needs a const value (not a dynamic variable of
>> + * reg-a0) or BUILD_BUG_ON failed with "idx >= __end_of_fixed_addresses".
>> + * So use '__always_inline' and 'const unsigned int fixmap' here.
>> + */
>> +static __always_inline void *patch_map(void *addr, const unsigned int fixmap)
>> {
>> uintptr_t uintaddr = (uintptr_t) addr;
>> struct page *page;
>> @@ -37,7 +42,6 @@ static void *patch_map(void *addr, int fixmap)
>> return (void *)set_fixmap_offset(fixmap, page_to_phys(page) +
>> (uintaddr & ~PAGE_MASK));
>> }
>> -NOKPROBE_SYMBOL(patch_map);
>>
>> static void patch_unmap(int fixmap)
>> {
>> --
>> 2.7.4
>>

2020-06-30 00:16:53

by Guo Ren

Subject: Re: [PATCH V2] riscv: Fixup compile error BUILD_BUG_ON failed

Hi Palmer,

On Tue, Jun 30, 2020 at 7:22 AM Palmer Dabbelt <[email protected]> wrote:
>
> On Sun, 28 Jun 2020 09:25:24 PDT (-0700), [email protected] wrote:
> > On Sun, 28 Jun 2020 16:07:37 +0000
> > [email protected] wrote:
> >
> >> From: Guo Ren <[email protected]>
> >>
> >> Unfortunately, the current code couldn't be compiled:
> >>
> >> CC arch/riscv/kernel/patch.o
> >> In file included from ./include/linux/kernel.h:11,
> >> from ./include/linux/list.h:9,
> >> from ./include/linux/preempt.h:11,
> >> from ./include/linux/spinlock.h:51,
> >> from arch/riscv/kernel/patch.c:6:
> >> In function ‘fix_to_virt’,
> >> inlined from ‘patch_map’ at arch/riscv/kernel/patch.c:37:17:
> >> ./include/linux/compiler.h:392:38: error: call to ‘__compiletime_assert_205’ declared with attribute error: BUILD_BUG_ON failed: idx >= __end_of_fixed_addresses
> >> _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
> >> ^
> >> ./include/linux/compiler.h:373:4: note: in definition of macro ‘__compiletime_assert’
> >> prefix ## suffix(); \
> >> ^~~~~~
> >> ./include/linux/compiler.h:392:2: note: in expansion of macro ‘_compiletime_assert’
> >> _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
> >> ^~~~~~~~~~~~~~~~~~~
> >> ./include/linux/build_bug.h:39:37: note: in expansion of macro ‘compiletime_assert’
> >> #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
> >> ^~~~~~~~~~~~~~~~~~
> >> ./include/linux/build_bug.h:50:2: note: in expansion of macro ‘BUILD_BUG_ON_MSG’
> >> BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
> >> ^~~~~~~~~~~~~~~~
> >> ./include/asm-generic/fixmap.h:32:2: note: in expansion of macro ‘BUILD_BUG_ON’
> >> BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
> >> ^~~~~~~~~~~~
> >>
> >> Because fix_to_virt(, idx) needs a const value, not a dynamic variable of
> >> reg-a0 or BUILD_BUG_ON failed with "idx >= __end_of_fixed_addresses".
> >
> > Looks good to me :)
> >
> > Reviewed-by: Masami Hiramatsu <[email protected]>
>
> Is there a configuration that runs into this bug? It's not showing up for me,
> and I generally try to add regressions to my test suite.
>
> > Thanks!

KPROBE, I'll send the patch soon.

--
Best Regards
Guo Ren

ML: https://lore.kernel.org/linux-csky/