diff mbox series

[v6,14/18] arm64: __show_regs: strip PAC from lr in printk

Message ID 1583476525-13505-15-git-send-email-amit.kachhap@arm.com (mailing list archive)
State New, archived
Headers show
Series arm64: return address signing | expand

Commit Message

Amit Daniel Kachhap March 6, 2020, 6:35 a.m. UTC 
lr is printed with %pS which will try to find an entry in kallsyms.
After enabling pointer authentication, this match will fail due to
PAC present in the lr.

Strip PAC from the lr to display the correct symbol name.

Suggested-by: James Morse <james.morse@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
---
 arch/arm64/kernel/process.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Vincenzo Frascino March 10, 2020, 3:11 p.m. UTC | #1 
On 3/6/20 6:35 AM, Amit Daniel Kachhap wrote:
> lr is printed with %pS which will try to find an entry in kallsyms.
> After enabling pointer authentication, this match will fail due to
> PAC present in the lr.
> 
> Strip PAC from the lr to display the correct symbol name.
>

Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>

> Suggested-by: James Morse <james.morse@arm.com>
> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
> Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
> ---
>  arch/arm64/kernel/process.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
> index 7db0302..cacae29 100644
> --- a/arch/arm64/kernel/process.c
> +++ b/arch/arm64/kernel/process.c
> @@ -262,7 +262,7 @@ void __show_regs(struct pt_regs *regs)
>  
>  	if (!user_mode(regs)) {
>  		printk("pc : %pS\n", (void *)regs->pc);
> -		printk("lr : %pS\n", (void *)lr);
> +		printk("lr : %pS\n", (void *)ptrauth_strip_insn_pac(lr));
>  	} else {
>  		printk("pc : %016llx\n", regs->pc);
>  		printk("lr : %016llx\n", lr);
>
diff mbox series

Patch

diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 7db0302..cacae29 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -262,7 +262,7 @@  void __show_regs(struct pt_regs *regs)
 
 	if (!user_mode(regs)) {
 		printk("pc : %pS\n", (void *)regs->pc);
-		printk("lr : %pS\n", (void *)lr);
+		printk("lr : %pS\n", (void *)ptrauth_strip_insn_pac(lr));
 	} else {
 		printk("pc : %016llx\n", regs->pc);
 		printk("lr : %016llx\n", lr);