[PATCH v2 0/2] riscv: signal: fix the size of signal frame

[PATCH v2 0/2] riscv: signal: fix the size of signal frame

[Yong-Xuan Wang]

This series addresses two issues about the RISC-V signal frame size
calculation. PATCH1 removes the unnecessary header preservation for the
END header. PATCH2 reorders the apply_boot_alternatives() and
init_rt_signal_env() to get the correct signal_minsigstksz.

Yong-Xuan Wang (2):
  riscv: signal: fix signal frame size
  riscv: signal: fix signal_minsigstksz

---
v2:
- Remove the refactor of init_rt_signal_env(). Instead, we can just
  put it after apply_boot_alternatives(). (Andy)
---

 arch/riscv/kernel/setup.c  | 2 +-
 arch/riscv/kernel/signal.c | 6 ------
 2 files changed, 1 insertion(+), 7 deletions(-)

-- 
2.17.1

[PATCH v2 1/2] riscv: signal: fix signal frame size

[Yong-Xuan Wang]

The signal context of certain RISC-V extensions will be appended after
struct __riscv_extra_ext_header, which already includes an empty context
header. Therefore, there is no need to preserve a separate hdr for the
END of signal context.

Fixes: 8ee0b41898fa ("riscv: signal: Add sigcontext save/restore for vector")
Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
Reviewed-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Andy Chiu <AndybnAC@gmail.com>
---
 arch/riscv/kernel/signal.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index dcd282419456..c3c517b9eee5 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -215,12 +215,6 @@ static size_t get_rt_frame_size(bool cal_all)
 		if (cal_all || riscv_v_vstate_query(task_pt_regs(current)))
 			total_context_size += riscv_v_sc_size;
 	}
-	/*
-	 * Preserved a __riscv_ctx_hdr for END signal context header if an
-	 * extension uses __riscv_extra_ext_header
-	 */
-	if (total_context_size)
-		total_context_size += sizeof(struct __riscv_ctx_hdr);
 
 	frame_size += total_context_size;
 
-- 
2.17.1

[PATCH v2 2/2] riscv: signal: fix signal_minsigstksz

[Yong-Xuan Wang]

The init_rt_signal_env() funciton is called before the alternative patch
is applied, so using the alternative-related API to check the availability
of an extension within this function doesn't have the intended effect.
This patch reorders the init_rt_signal_env() and apply_boot_alternatives()
to get the correct signal_minsigstksz.

Fixes: e92f469b0771 ("riscv: signal: Report signal frame size to userspace via auxv")
Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
Reviewed-by: Zong Li <zong.li@sifive.com>
---
 arch/riscv/kernel/setup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 016b48fcd6f2..b7c91f546453 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -324,8 +324,8 @@ void __init setup_arch(char **cmdline_p)
 
 	riscv_init_cbo_blocksizes();
 	riscv_fill_hwcap();
-	init_rt_signal_env();
 	apply_boot_alternatives();
+	init_rt_signal_env();
 
 	if (IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM) &&
 	    riscv_isa_extension_available(NULL, ZICBOM))
-- 
2.17.1

Re: [PATCH v2 2/2] riscv: signal: fix signal_minsigstksz

[Andy Chiu]

Hi Yong-Xuan,

Yong-Xuan Wang <yongxuan.wang@sifive.com> 於 2024年12月20日 週五 下午4:39寫道：
>
> The init_rt_signal_env() funciton is called before the alternative patch
> is applied, so using the alternative-related API to check the availability
> of an extension within this function doesn't have the intended effect.
> This patch reorders the init_rt_signal_env() and apply_boot_alternatives()
> to get the correct signal_minsigstksz.
>
> Fixes: e92f469b0771 ("riscv: signal: Report signal frame size to userspace via auxv")
> Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
> Reviewed-by: Zong Li <zong.li@sifive.com>

Reviewed-by: Andy Chiu <andybnac@gmail.com>

> ---
>  arch/riscv/kernel/setup.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
> index 016b48fcd6f2..b7c91f546453 100644
> --- a/arch/riscv/kernel/setup.c
> +++ b/arch/riscv/kernel/setup.c
> @@ -324,8 +324,8 @@ void __init setup_arch(char **cmdline_p)
>
>         riscv_init_cbo_blocksizes();
>         riscv_fill_hwcap();
> -       init_rt_signal_env();
>         apply_boot_alternatives();
> +       init_rt_signal_env();
>
>         if (IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM) &&
>             riscv_isa_extension_available(NULL, ZICBOM))
> --
> 2.17.1
>

Thanks,
Andy

Re: [PATCH v2 1/2] riscv: signal: fix signal frame size

[Alexandre Ghiti]

Hi Yong-Xuan,

On 20/12/2024 09:39, Yong-Xuan Wang wrote:
> The signal context of certain RISC-V extensions will be appended after
> struct __riscv_extra_ext_header, which already includes an empty context
> header. Therefore, there is no need to preserve a separate hdr for the
> END of signal context.
>
> Fixes: 8ee0b41898fa ("riscv: signal: Add sigcontext save/restore for vector")
> Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
> Reviewed-by: Zong Li <zong.li@sifive.com>
> Reviewed-by: Andy Chiu <AndybnAC@gmail.com>
> ---
>   arch/riscv/kernel/signal.c | 6 ------
>   1 file changed, 6 deletions(-)
>
> diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
> index dcd282419456..c3c517b9eee5 100644
> --- a/arch/riscv/kernel/signal.c
> +++ b/arch/riscv/kernel/signal.c
> @@ -215,12 +215,6 @@ static size_t get_rt_frame_size(bool cal_all)
>   		if (cal_all || riscv_v_vstate_query(task_pt_regs(current)))
>   			total_context_size += riscv_v_sc_size;
>   	}
> -	/*
> -	 * Preserved a __riscv_ctx_hdr for END signal context header if an
> -	 * extension uses __riscv_extra_ext_header
> -	 */
> -	if (total_context_size)
> -		total_context_size += sizeof(struct __riscv_ctx_hdr);
>   
>   	frame_size += total_context_size;
>   


Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>

Thanks,

Alex

Re: [PATCH v2 2/2] riscv: signal: fix signal_minsigstksz

[Alexandre Ghiti]

Hi Yong-Xuan,

On 20/12/2024 09:39, Yong-Xuan Wang wrote:
> The init_rt_signal_env() funciton is called before the alternative patch
> is applied, so using the alternative-related API to check the availability
> of an extension within this function doesn't have the intended effect.
> This patch reorders the init_rt_signal_env() and apply_boot_alternatives()
> to get the correct signal_minsigstksz.
>
> Fixes: e92f469b0771 ("riscv: signal: Report signal frame size to userspace via auxv")
> Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
> Reviewed-by: Zong Li <zong.li@sifive.com>
> ---
>   arch/riscv/kernel/setup.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
> index 016b48fcd6f2..b7c91f546453 100644
> --- a/arch/riscv/kernel/setup.c
> +++ b/arch/riscv/kernel/setup.c
> @@ -324,8 +324,8 @@ void __init setup_arch(char **cmdline_p)
>   
>   	riscv_init_cbo_blocksizes();
>   	riscv_fill_hwcap();
> -	init_rt_signal_env();
>   	apply_boot_alternatives();
> +	init_rt_signal_env();
>   
>   	if (IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM) &&
>   	    riscv_isa_extension_available(NULL, ZICBOM))


Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>

Thanks for your fixes!

Alex

Re: [PATCH v2 0/2] riscv: signal: fix the size of signal frame

[patchwork-bot+linux-riscv]

Hello:

This series was applied to riscv/linux.git (fixes)
by Palmer Dabbelt <palmer@rivosinc.com>:

On Fri, 20 Dec 2024 16:39:22 +0800 you wrote:
> This series addresses two issues about the RISC-V signal frame size
> calculation. PATCH1 removes the unnecessary header preservation for the
> END header. PATCH2 reorders the apply_boot_alternatives() and
> init_rt_signal_env() to get the correct signal_minsigstksz.
> 
> Yong-Xuan Wang (2):
>   riscv: signal: fix signal frame size
>   riscv: signal: fix signal_minsigstksz
> 
> [...]

Here is the summary with links:
  - [v2,1/2] riscv: signal: fix signal frame size
    https://git.kernel.org/riscv/c/0eeb13956757
  - [v2,2/2] riscv: signal: fix signal_minsigstksz
    https://git.kernel.org/riscv/c/5338770fc74b

You are awesome, thank you!
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