Re: [PATCH v2] arm64: SSBS/DIT: print SSBS and DIT bit when printing PSTATE

On Wed, Jul 21, 2021 at 09:31:18AM +0100, Vladimir Murzin wrote:

On 7/21/21 3:43 AM, Shaokun Zhang wrote:

quoted

From: Lingyan Huang <redacted>

The current code to print PSTATE when generating backtraces does not
include SSBS bit and DIT bit, so add this information.

Cc: Vladimir Murzin <redacted>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Lingyan Huang <redacted>
Signed-off-by: Shaokun Zhang <redacted>
---
ChangeLog:
v1-->v2:
    1. Address Vladimir's comment on update compat_user_mode

 arch/arm64/kernel/process.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index c8989b999250..3da2ad00fa0c 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c

@@ -163,7 +163,7 @@ static void print_pstate(struct pt_regs *regs)
 	u64 pstate = regs->pstate;
 
 	if (compat_user_mode(regs)) {
-		printk("pstate: %08llx (%c%c%c%c %c %s %s %c%c%c)\n",
+		printk("pstate: %08llx (%c%c%c%c %c %s %s %c%c%c %cPAN %cDIT %cSSBS)\n",
 			pstate,
 			pstate & PSR_AA32_N_BIT ? 'N' : 'n',
 			pstate & PSR_AA32_Z_BIT ? 'Z' : 'z',

@@ -174,12 +174,15 @@ static void print_pstate(struct pt_regs *regs)
 			pstate & PSR_AA32_E_BIT ? "BE" : "LE",
 			pstate & PSR_AA32_A_BIT ? 'A' : 'a',
 			pstate & PSR_AA32_I_BIT ? 'I' : 'i',
-			pstate & PSR_AA32_F_BIT ? 'F' : 'f');
+			pstate & PSR_AA32_F_BIT ? 'F' : 'f',
+			pstate & PSR_AA32_PAN_BIT ? '+' : '-',

Hmm, commit message doesn't mention PAN bit... but I leave it to maintainers.

Agreed, I don't see the rationale for exposing PAN for 32-bit userspace
tasks. Please drop this part for v3.

Will

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