diff mbox series

[v5,4/4] lib: sbi: fwft: implement landing pad and shadow stack fwft interface

Message ID 20240910163522.2584936-5-debug@rivosinc.com
State Superseded
Headers show
Series zicfilp and zicfiss support in opensbi | expand

Commit Message

Deepak Gupta Sept. 10, 2024, 4:35 p.m. UTC 
Supervisor software can enable control flow integrity features for itself
using fwft feature `SBI_FWFT_LANDING_PAD` and `SBI_FWFT_SHADOW_STACK`.
This patch implements the mechanism to enable both these fwft.

Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Clément Léger <cleger@rivosinc.com>
---
 lib/sbi/sbi_fwft.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

Comments

Samuel Holland Sept. 14, 2024, 5:07 p.m. UTC | #1 
Hi Deepak,

On 2024-09-10 11:35 AM, Deepak Gupta wrote:
> Supervisor software can enable control flow integrity features for itself
> using fwft feature `SBI_FWFT_LANDING_PAD` and `SBI_FWFT_SHADOW_STACK`.
> This patch implements the mechanism to enable both these fwft.
> 
> Signed-off-by: Deepak Gupta <debug@rivosinc.com>
> Reviewed-by: Atish Patra <atishp@rivosinc.com>
> Reviewed-by: Clément Léger <cleger@rivosinc.com>
> ---
>  lib/sbi/sbi_fwft.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 74 insertions(+)
> 
> diff --git a/lib/sbi/sbi_fwft.c b/lib/sbi/sbi_fwft.c
> index ef881ef..747bc88 100644
> --- a/lib/sbi/sbi_fwft.c
> +++ b/lib/sbi/sbi_fwft.c
> @@ -145,6 +145,68 @@ static int fwft_get_adue(struct fwft_config *conf, unsigned long *value)
>  	return SBI_OK;
>  }
>  
> +static int fwft_lpad_supported(struct fwft_config *conf)
> +{
> +	if (!sbi_hart_has_extension(sbi_scratch_thishart_ptr(),
> +				    SBI_HART_EXT_ZICFILP))
> +		return SBI_ENOTSUPP;
> +
> +	return SBI_OK;
> +}
> +
> +static int fwft_enable_lpad(struct fwft_config *conf, unsigned long value)
> +{
> +	if (value == 1)
> +		csr_set(CSR_MENVCFG, ENVCFG_LPE);
> +	else if (value == 0)
> +		csr_clear(CSR_MENVCFG, ENVCFG_LPE);
> +	else
> +		return SBI_EINVAL;
> +
> +	return SBI_OK;
> +}
> +
> +static int fwft_get_lpad(struct fwft_config *conf, unsigned long *value)
> +{
> +	unsigned long cfg;
> +
> +	cfg = csr_read(CSR_MENVCFG) & ENVCFG_LPE;
> +	*value = cfg != 0;
> +
> +	return SBI_OK;
> +}
> +
> +static int fwft_sstack_supported(struct fwft_config *conf)
> +{
> +	if (!sbi_hart_has_extension(sbi_scratch_thishart_ptr(),
> +				    SBI_HART_EXT_ZICFISS))
> +		return SBI_ENOTSUPP;
> +
> +	return SBI_OK;
> +}
> +
> +static int fwft_enable_sstack(struct fwft_config *conf, unsigned long value)
> +{
> +	if (value == 1)
> +		csr_set(CSR_MENVCFG, ENVCFG_SSE);
> +	else if (value == 0)
> +		csr_clear(CSR_MENVCFG, ENVCFG_SSE);
> +	else
> +		return SBI_EINVAL;
> +
> +	return SBI_OK;
> +}
> +
> +static int fwft_get_sstack(struct fwft_config *conf, unsigned long *value)
> +{
> +	unsigned long cfg;
> +
> +	cfg = csr_read(CSR_MENVCFG) & ENVCFG_SSE;
> +	*value = cfg != 0;
> +
> +	return SBI_OK;
> +}
> +
>  static struct fwft_config* get_feature_config(enum sbi_fwft_feature_t feature)
>  {
>  	int i;
> @@ -236,6 +298,18 @@ static const struct fwft_feature features[] =
>  		.set = fwft_set_adue,
>  		.get = fwft_get_adue,
>  	},
> +	{
> +		.id = SBI_FWFT_LANDING_PAD,
> +		.supported = fwft_lpad_supported,
> +		.set = fwft_enable_lpad,
> +		.get = fwft_get_lpad,
> +	},
> +	{
> +		.id = SBI_FWFT_SHADOW_STACK,
> +		.supported = fwft_sstack_supported,
> +		.set = fwft_enable_sstack,
> +		.get = fwft_get_sstack,
> +	},

Please keep these blocks (and the new functions) sorted by feature ID, so above
ADUE.

Regards,
Samuel

>  };
>  
>  int sbi_fwft_init(struct sbi_scratch *scratch, bool cold_boot)
diff mbox series

Patch

diff --git a/lib/sbi/sbi_fwft.c b/lib/sbi/sbi_fwft.c
index ef881ef..747bc88 100644
--- a/lib/sbi/sbi_fwft.c
+++ b/lib/sbi/sbi_fwft.c
@@ -145,6 +145,68 @@  static int fwft_get_adue(struct fwft_config *conf, unsigned long *value)
 	return SBI_OK;
 }
 
+static int fwft_lpad_supported(struct fwft_config *conf)
+{
+	if (!sbi_hart_has_extension(sbi_scratch_thishart_ptr(),
+				    SBI_HART_EXT_ZICFILP))
+		return SBI_ENOTSUPP;
+
+	return SBI_OK;
+}
+
+static int fwft_enable_lpad(struct fwft_config *conf, unsigned long value)
+{
+	if (value == 1)
+		csr_set(CSR_MENVCFG, ENVCFG_LPE);
+	else if (value == 0)
+		csr_clear(CSR_MENVCFG, ENVCFG_LPE);
+	else
+		return SBI_EINVAL;
+
+	return SBI_OK;
+}
+
+static int fwft_get_lpad(struct fwft_config *conf, unsigned long *value)
+{
+	unsigned long cfg;
+
+	cfg = csr_read(CSR_MENVCFG) & ENVCFG_LPE;
+	*value = cfg != 0;
+
+	return SBI_OK;
+}
+
+static int fwft_sstack_supported(struct fwft_config *conf)
+{
+	if (!sbi_hart_has_extension(sbi_scratch_thishart_ptr(),
+				    SBI_HART_EXT_ZICFISS))
+		return SBI_ENOTSUPP;
+
+	return SBI_OK;
+}
+
+static int fwft_enable_sstack(struct fwft_config *conf, unsigned long value)
+{
+	if (value == 1)
+		csr_set(CSR_MENVCFG, ENVCFG_SSE);
+	else if (value == 0)
+		csr_clear(CSR_MENVCFG, ENVCFG_SSE);
+	else
+		return SBI_EINVAL;
+
+	return SBI_OK;
+}
+
+static int fwft_get_sstack(struct fwft_config *conf, unsigned long *value)
+{
+	unsigned long cfg;
+
+	cfg = csr_read(CSR_MENVCFG) & ENVCFG_SSE;
+	*value = cfg != 0;
+
+	return SBI_OK;
+}
+
 static struct fwft_config* get_feature_config(enum sbi_fwft_feature_t feature)
 {
 	int i;
@@ -236,6 +298,18 @@  static const struct fwft_feature features[] =
 		.set = fwft_set_adue,
 		.get = fwft_get_adue,
 	},
+	{
+		.id = SBI_FWFT_LANDING_PAD,
+		.supported = fwft_lpad_supported,
+		.set = fwft_enable_lpad,
+		.get = fwft_get_lpad,
+	},
+	{
+		.id = SBI_FWFT_SHADOW_STACK,
+		.supported = fwft_sstack_supported,
+		.set = fwft_enable_sstack,
+		.get = fwft_get_sstack,
+	},
 };
 
 int sbi_fwft_init(struct sbi_scratch *scratch, bool cold_boot)