[PATCH] powerpc/kernel: Print actual address of regs when oopsing

[PATCH] powerpc/kernel: Print actual address of regs when oopsing

[Michael Ellerman]

When we oops or otherwise call show_regs() we print the address of the
regs structure. Being able to see the address is fairly useful,
firstly to verify that the regs pointer is not completely bogus, and
secondly it allows you to dump the regs and surrounding memory with a
debugger if you have one.

In the normal case the regs will be located somewhere on the stack, so
printing their location discloses no further information than printing
the stack pointer does already.

So switch to %px and print the actual address, not the hashed value.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/kernel/process.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 5acb5a176dbe..72be0c32e902 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1403,7 +1403,7 @@ void show_regs(struct pt_regs * regs)
 
 	printk("NIP:  "REG" LR: "REG" CTR: "REG"\n",
 	       regs->nip, regs->link, regs->ctr);
-	printk("REGS: %p TRAP: %04lx   %s  (%s)\n",
+	printk("REGS: %px TRAP: %04lx   %s  (%s)\n",
 	       regs, regs->trap, print_tainted(), init_utsname()->release);
 	printk("MSR:  "REG" ", regs->msr);
 	print_msr_bits(regs->msr);
-- 
2.14.3

Re: powerpc/kernel: Print actual address of regs when oopsing

[Michael Ellerman]

On Thu, 2018-01-11 at 02:21:35 UTC, Michael Ellerman wrote:
> When we oops or otherwise call show_regs() we print the address of the
> regs structure. Being able to see the address is fairly useful,
> firstly to verify that the regs pointer is not completely bogus, and
> secondly it allows you to dump the regs and surrounding memory with a
> debugger if you have one.
> 
> In the normal case the regs will be located somewhere on the stack, so
> printing their location discloses no further information than printing
> the stack pointer does already.
> 
> So switch to %px and print the actual address, not the hashed value.
> 
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Applied to powerpc fixes.

https://git.kernel.org/powerpc/c/182dc9c7f217146d69d9c0b75c150c

cheers