[Linaro-uefi,1/3] Platforms/AMD/Styx/PlatformSmbiosDxe: don't write to string literals

Remove the code from PlatformSmbiosDxe that writes to a string literal
to turn the string 'L# Cache' into L1/L2/L3, and just emit the three
versions instead. This is necessary given that string literals are
emitted into .rodata by default, which makes them read-only when strict
memory permissions are in effect.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 Platforms/AMD/Styx/Drivers/PlatformSmbiosDxe/PlatformSmbiosDxe.c | 21 ++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

On 27 February 2017 at 18:02, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
> Remove the code from PlatformSmbiosDxe that writes to a string literal
> to turn the string 'L# Cache' into L1/L2/L3, and just emit the three
> versions instead. This is necessary given that string literals are
> emitted into .rodata by default, which makes them read-only when strict
> memory permissions are in effect.
>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
>  Platforms/AMD/Styx/Drivers/PlatformSmbiosDxe/PlatformSmbiosDxe.c | 21 ++++++++++++--------
>  1 file changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/Platforms/AMD/Styx/Drivers/PlatformSmbiosDxe/PlatformSmbiosDxe.c b/Platforms/AMD/Styx/Drivers/PlatformSmbiosDxe/PlatformSmbiosDxe.c
> index 5ee5d92fdf9c..14e3cc409dbc 100644
> --- a/Platforms/AMD/Styx/Drivers/PlatformSmbiosDxe/PlatformSmbiosDxe.c
> +++ b/Platforms/AMD/Styx/Drivers/PlatformSmbiosDxe/PlatformSmbiosDxe.c
> @@ -355,8 +355,16 @@ SMBIOS_TABLE_TYPE7  mCacheInfoType7 = {
>    CacheAssociativity2Way        // Associativity
>  };
>  #if (FixedPcdGetBool (PcdIscpSupport))
> -CHAR8  *mCacheInfoType7Strings[] = {
> -  "L# Cache",
> +CHAR8  *mCacheInfoType7StringsL1[] = {
> +  "L1 Cache",
> +  NULL
> +};
> +CHAR8  *mCacheInfoType7StringsL2[] = {
> +  "L2 Cache",
> +  NULL
> +};
> +CHAR8  *mCacheInfoType7StringsL3[] = {
> +  "L3 Cache",
>    NULL
>  };

Actually, this is a bit overkill: we can simply keep a single version
and assign a different char pointer to element 0 for each of L1, L2
and L3 cache rather than update the digit 3 times.

>  #else
> @@ -710,7 +718,6 @@ CacheInfoUpdateSmbiosType7 (
>    dstType7.SocketDesignation = 1;  // "L# Cache"
>
>    // L1 cache settings
> -  mCacheInfoType7Strings[0][1] = '1'; // "L# Cache" --> "L1 Cache"
>    SmbiosT7 = &mSmbiosInfo.SmbiosCpuBuffer.T7L1[0];
>    dstType7.CacheConfiguration  = SmbiosT7->T7CacheCfg;
>    dstType7.MaximumCacheSize    = SmbiosT7->T7MaxCacheSize;
> @@ -723,10 +730,9 @@ CacheInfoUpdateSmbiosType7 (
>    dstType7.ErrorCorrectionType = SmbiosT7->T7ErrorCorrectionType;
>    dstType7.SystemCacheType     = SmbiosT7->T7SystemCacheType;
>    dstType7.Associativity       = SmbiosT7->T7Associativity;
> -  LogSmbiosData ((EFI_SMBIOS_TABLE_HEADER *)&dstType7, mCacheInfoType7Strings);
> +  LogSmbiosData ((EFI_SMBIOS_TABLE_HEADER *)&dstType7, mCacheInfoType7StringsL1);
>
>    // L2 cache settings
> -  mCacheInfoType7Strings[0][1] = '2'; // "L# Cache" --> "L2 Cache"
>    SmbiosT7 = &mSmbiosInfo.SmbiosCpuBuffer.T7L2[0];
>    dstType7.CacheConfiguration  = SmbiosT7->T7CacheCfg;
>    dstType7.MaximumCacheSize    = SmbiosT7->T7MaxCacheSize;
> @@ -739,10 +745,9 @@ CacheInfoUpdateSmbiosType7 (
>    dstType7.ErrorCorrectionType = SmbiosT7->T7ErrorCorrectionType;
>    dstType7.SystemCacheType     = SmbiosT7->T7SystemCacheType;
>    dstType7.Associativity       = SmbiosT7->T7Associativity;
> -  LogSmbiosData ((EFI_SMBIOS_TABLE_HEADER *)&dstType7, mCacheInfoType7Strings);
> +  LogSmbiosData ((EFI_SMBIOS_TABLE_HEADER *)&dstType7, mCacheInfoType7StringsL2);
>
>    // L3 cache settings
> -  mCacheInfoType7Strings[0][1] = '3'; // "L# Cache" --> "L3 Cache"
>    SmbiosT7 = &mSmbiosInfo.SmbiosCpuBuffer.T7L3[0];
>    dstType7.CacheConfiguration  = SmbiosT7->T7CacheCfg;
>    dstType7.MaximumCacheSize    = SmbiosT7->T7MaxCacheSize;
> @@ -755,7 +760,7 @@ CacheInfoUpdateSmbiosType7 (
>    dstType7.ErrorCorrectionType = SmbiosT7->T7ErrorCorrectionType;
>    dstType7.SystemCacheType     = SmbiosT7->T7SystemCacheType;
>    dstType7.Associativity       = SmbiosT7->T7Associativity;
> -  LogSmbiosData ((EFI_SMBIOS_TABLE_HEADER *)&dstType7, mCacheInfoType7Strings);
> +  LogSmbiosData ((EFI_SMBIOS_TABLE_HEADER *)&dstType7, mCacheInfoType7StringsL3);
>  #else
>    LogSmbiosData ((EFI_SMBIOS_TABLE_HEADER *)&mCacheInfoType7, mCacheInfoType7Strings);
>  #endif
> --
> 2.7.4
>