parisc: Only call VDSO32_SYMBOL() when valid

[PATCH] parisc: Only call VDSO32_SYMBOL() when valid

Posted by Thomas Weißschuh 1 month, 2 weeks ago

The definitions used by VDSO32_SYMBOL() only work if the 32-bit vDSO
actually exists.

Fixes: 3dce91790205 ("parisc: Allow to build without VDSO32")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 arch/parisc/kernel/signal.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/parisc/kernel/signal.c b/arch/parisc/kernel/signal.c
index 64a62006bb15..192121047633 100644
--- a/arch/parisc/kernel/signal.c
+++ b/arch/parisc/kernel/signal.c
@@ -276,7 +276,9 @@ setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs,
 		rp = VDSO64_SYMBOL(current, sigtramp_rt);
 	else
 #endif
+#if defined(CONFIG_PA11) || defined(CONFIG_COMPAT)
 		rp = VDSO32_SYMBOL(current, sigtramp_rt);
+#endif
 
 	if (in_syscall)
 		rp += 4*4; /* skip 4 instructions and start at ldi 1,%r25 */
@@ -514,10 +516,12 @@ insert_restart_trampoline(struct pt_regs *regs)
 			rp = VDSO64_SYMBOL(current, restart_syscall);
 		} else
 #endif
+#if defined(CONFIG_PA11) || defined(CONFIG_COMPAT)
 		{
 			err |= put_user(regs->gr[31], &usp[0]);
 			rp = VDSO32_SYMBOL(current, restart_syscall);
 		}
+#endif
 		WARN_ON(err);
 
 		regs->gr[31] = rp;

---
base-commit: 254f49634ee16a731174d2ae34bc50bd5f45e731
change-id: 20260428-parisc-compat-vdso-956b2a3a2123

Best regards,
--  
Thomas Weißschuh <linux@weissschuh.net>

Re: [PATCH] parisc: Only call VDSO32_SYMBOL() when valid

Posted by Helge Deller 1 month, 2 weeks ago

Hi Thomas,

On 4/29/26 22:59, Thomas Weißschuh wrote:
> The definitions used by VDSO32_SYMBOL() only work if the 32-bit vDSO
> actually exists.

Do you have a .config with which the problem can be reproduced?
  
> Fixes:  3dce91790205 ("parisc: Allow to build without VDSO32")
> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
> ---
>   arch/parisc/kernel/signal.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/arch/parisc/kernel/signal.c b/arch/parisc/kernel/signal.c
> index 64a62006bb15..192121047633 100644
> --- a/arch/parisc/kernel/signal.c
> +++ b/arch/parisc/kernel/signal.c
> @@ -276,7 +276,9 @@ setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs,
>   		rp = VDSO64_SYMBOL(current, sigtramp_rt);
>   	else
>   #endif
> +#if defined(CONFIG_PA11) || defined(CONFIG_COMPAT)
>   		rp = VDSO32_SYMBOL(current, sigtramp_rt);
> +#endif

This is wrong (dangerous).
If this BVDSO32_SYMBOL() line is left out, the "if (in_syscall)" below
is put together with the "else" in the VDSO64_SYMBOL() path above.


>   	if (in_syscall)
>   		rp += 4*4; /* skip 4 instructions and start at ldi 1,%r25 */
> @@ -514,10 +516,12 @@ insert_restart_trampoline(struct pt_regs *regs)
>   			rp = VDSO64_SYMBOL(current, restart_syscall);
>   		} else
>   #endif
> +#if defined(CONFIG_PA11) || defined(CONFIG_COMPAT)
>   		{
>   			err |= put_user(regs->gr[31], &usp[0]);
>   			rp = VDSO32_SYMBOL(current, restart_syscall);
>   		}
> +#endif

same here...

>   		WARN_ON(err);
>   
>   		regs->gr[31] = rp;
> 
> ---
> base-commit: 254f49634ee16a731174d2ae34bc50bd5f45e731
> change-id: 20260428-parisc-compat-vdso-956b2a3a2123
> 
> Best regards,
> --
> Thomas Weißschuh <linux@weissschuh.net>
>