2022-11-03 16:26:39

by Jiaxun Yang

Subject: [PATCH v2] MIPS: jump_label: Fix compat branch range check

Cast upper bound of branch range to long to do signed compare,
avoid negative offset trigger this warning.

Fixes: 9b6584e35f40 ("MIPS: jump_label: Use compact branches for >= r6")
Signed-off-by: Jiaxun Yang <[email protected]>
Cc: [email protected]
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
---
v2: Fix typo, collect review tags.
---
arch/mips/kernel/jump_label.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/kernel/jump_label.c b/arch/mips/kernel/jump_label.c
index 71a882c8c6eb..f7978d50a2ba 100644
--- a/arch/mips/kernel/jump_label.c
+++ b/arch/mips/kernel/jump_label.c
@@ -56,7 +56,7 @@ void arch_jump_label_transform(struct jump_entry *e,
* The branch offset must fit in the instruction's 26
* bit field.
*/
- WARN_ON((offset >= BIT(25)) ||
+ WARN_ON((offset >= (long)BIT(25)) ||
(offset < -(long)BIT(25)));

insn.j_format.opcode = bc6_op;
--
2.34.1

2022-11-09 12:00:56

by Jiaxun Yang

Subject: Re: [PATCH v2] MIPS: jump_label: Fix compat branch range check

在 2022/11/3 15:10, Jiaxun Yang 写道:
> Cast upper bound of branch range to long to do signed compare,
> avoid negative offset trigger this warning.
>
> Fixes: 9b6584e35f40 ("MIPS: jump_label: Use compact branches for >= r6")
> Signed-off-by: Jiaxun Yang <[email protected]>
> Cc: [email protected]
> Reviewed-by: Philippe Mathieu-Daudé <[email protected]>

Ping :-)

Thanks
- Jiaxun

> ---
> v2: Fix typo, collect review tags.
> ---
> arch/mips/kernel/jump_label.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/mips/kernel/jump_label.c b/arch/mips/kernel/jump_label.c
> index 71a882c8c6eb..f7978d50a2ba 100644
> --- a/arch/mips/kernel/jump_label.c
> +++ b/arch/mips/kernel/jump_label.c
> @@ -56,7 +56,7 @@ void arch_jump_label_transform(struct jump_entry *e,
> * The branch offset must fit in the instruction's 26
> * bit field.
> */
> - WARN_ON((offset >= BIT(25)) ||
> + WARN_ON((offset >= (long)BIT(25)) ||
> (offset < -(long)BIT(25)));
>
> insn.j_format.opcode = bc6_op;

2022-11-11 15:27:05

by Thomas Bogendoerfer

Subject: Re: [PATCH v2] MIPS: jump_label: Fix compat branch range check

On Thu, Nov 03, 2022 at 03:10:53PM +0000, Jiaxun Yang wrote:
> Cast upper bound of branch range to long to do signed compare,
> avoid negative offset trigger this warning.
>
> Fixes: 9b6584e35f40 ("MIPS: jump_label: Use compact branches for >= r6")
> Signed-off-by: Jiaxun Yang <[email protected]>
> Cc: [email protected]
> Reviewed-by: Philippe Mathieu-Daud? <[email protected]>
> ---
> v2: Fix typo, collect review tags.
> ---
> arch/mips/kernel/jump_label.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/mips/kernel/jump_label.c b/arch/mips/kernel/jump_label.c
> index 71a882c8c6eb..f7978d50a2ba 100644
> --- a/arch/mips/kernel/jump_label.c
> +++ b/arch/mips/kernel/jump_label.c
> @@ -56,7 +56,7 @@ void arch_jump_label_transform(struct jump_entry *e,
> * The branch offset must fit in the instruction's 26
> * bit field.
> */
> - WARN_ON((offset >= BIT(25)) ||
> + WARN_ON((offset >= (long)BIT(25)) ||
> (offset < -(long)BIT(25)));
>
> insn.j_format.opcode = bc6_op;
> --
> 2.34.1

applied to mips-fixes.

Thomas.

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