On Sun, 28 Jun 2020 16:07:37 +0000
guoren@xxxxxxxxxx wrote:
> From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
>
> 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 <mhiramat@xxxxxxxxxx>
Thanks!
>
> Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
> Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> Cc: Zong Li <zong.li@xxxxxxxxxx>
> ---
> Changelog V2:
> - Use __always_inline as same as fix_to_virt
> - Use const "const unsigned int" for 2th param
>
> Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
> ---
> 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 <mhiramat@xxxxxxxxxx>
