2021-06-02 08:36:15

by Kefeng Wang

Subject: [PATCH v2 6/7] ARM: mm: Provide die_kernel_fault() helper

Provide die_kernel_fault() helper to do the kernel fault reporting,
which with msg argument, it could report different message in different
scenes, and the later patch "ARM: mm: Fix PXN process with LPAE feature"
will use it.

Signed-off-by: Kefeng Wang <[email protected]>
---
arch/arm/mm/fault.c | 29 ++++++++++++++++++++---------
1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 1383d465399b..7cfa9a59d3ec 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -108,12 +108,27 @@ void show_pte(const char *lvl, unsigned long addr)
{ }
#endif /* CONFIG_MMU */

+static void die_kernel_fault(const char *msg, unsigned long addr,
+ unsigned int fsr, struct pt_regs *regs)
+{
+ bust_spinlocks(1);
+ pr_alert("8<--- cut here ---\n");
+ pr_alert("Unable to handle kernel %s at virtual address %08lx\n",
+ msg, addr);
+
+ show_pte(KERN_ALERT, addr);
+ die("Oops", regs, fsr);
+ bust_spinlocks(0);
+ do_exit(SIGKILL);
+}
+
/*
* Oops. The kernel tried to access some page that wasn't present.
*/
static void
__do_kernel_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
{
+ const char *msg;
/*
* Are we prepared to handle this kernel fault?
*/
@@ -123,16 +138,12 @@ __do_kernel_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
/*
* No handler, we'll have to terminate things with extreme prejudice.
*/
- bust_spinlocks(1);
- pr_alert("8<--- cut here ---\n");
- pr_alert("Unable to handle kernel %s at virtual address %08lx\n",
- (addr < PAGE_SIZE) ? "NULL pointer dereference" :
- "paging request", addr);
+ if (addr < PAGE_SIZE)
+ msg = "NULL pointer dereference";
+ else
+ msg = "paging request";

- show_pte(KERN_ALERT, addr);
- die("Oops", regs, fsr);
- bust_spinlocks(0);
- do_exit(SIGKILL);
+ die_kernel_fault(msg, addr, fsr, regs);
}

/*
--
2.26.2

2021-06-02 10:54:16

by Russell King (Oracle)

Subject: Re: [PATCH v2 6/7] ARM: mm: Provide die_kernel_fault() helper

Hi,

On Wed, Jun 02, 2021 at 03:02:45PM +0800, Kefeng Wang wrote:
> Provide die_kernel_fault() helper to do the kernel fault reporting,
> which with msg argument, it could report different message in different
> scenes, and the later patch "ARM: mm: Fix PXN process with LPAE feature"
> will use it.

This looks fine to me, thanks.

--
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