2024-01-18 15:53:36

by Gregory CLEMENT

Subject: [PATCH v6 04/15] MIPS: traps: Give more explanations if ebase doesn't belong to KSEG0

With the expanded support for placing the kernel in XPHYS rather than
just KSEG0, scenarios where ebase doesn't belong to KSEG0 are more
likely to occur. In such cases, we currently experience a substantial
and perplexing stack dump without any accompanying explanation. To
rectify this, we aim to replace the uninformative stack dump with a
warning that offers a clear explanation of the issue.

Signed-off-by: Gregory CLEMENT <[email protected]>
---
arch/mips/kernel/traps.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 355d0f0709de8..911d2233d6d0b 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -2347,10 +2347,13 @@ void __init trap_init(void)
* EVA is special though as it allows segments to be rearranged
* and to become uncached during cache error handling.
*/
- if (!IS_ENABLED(CONFIG_EVA) && !WARN_ON(ebase_pa >= 0x20000000))
+ if (!IS_ENABLED(CONFIG_EVA) && ebase_pa < 0x20000000)
ebase = CKSEG0ADDR(ebase_pa);
else
ebase = (unsigned long)phys_to_virt(ebase_pa);
+ if (ebase_pa >= 0x20000000)
+ pr_warn("ebase(%pa) should better be in KSeg0",
+ &ebase_pa);
}

if (cpu_has_mmips) {
--
2.43.0

2024-01-19 09:58:24

by Jiaxun Yang

Subject: Re: [PATCH v6 04/15] MIPS: traps: Give more explanations if ebase doesn't belong to KSEG0

在 2024/1/18 15:52, Gregory CLEMENT 写道:
> With the expanded support for placing the kernel in XPHYS rather than
> just KSEG0, scenarios where ebase doesn't belong to KSEG0 are more
> likely to occur. In such cases, we currently experience a substantial
> and perplexing stack dump without any accompanying explanation. To
> rectify this, we aim to replace the uninformative stack dump with a
> warning that offers a clear explanation of the issue.
>
> Signed-off-by: Gregory CLEMENT <[email protected]>

Reviewed-by: Jiaxun Yang <[email protected]>

> ---
> arch/mips/kernel/traps.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
> index 355d0f0709de8..911d2233d6d0b 100644
> --- a/arch/mips/kernel/traps.c
> +++ b/arch/mips/kernel/traps.c
> @@ -2347,10 +2347,13 @@ void __init trap_init(void)
> * EVA is special though as it allows segments to be rearranged
> * and to become uncached during cache error handling.
> */
> - if (!IS_ENABLED(CONFIG_EVA) && !WARN_ON(ebase_pa >= 0x20000000))
> + if (!IS_ENABLED(CONFIG_EVA) && ebase_pa < 0x20000000)
> ebase = CKSEG0ADDR(ebase_pa);
> else
> ebase = (unsigned long)phys_to_virt(ebase_pa);
> + if (ebase_pa >= 0x20000000)
> + pr_warn("ebase(%pa) should better be in KSeg0",
> + &ebase_pa);
> }
>
> if (cpu_has_mmips) {

--
---
Jiaxun Yang