Where the value of current is kept in a register, that register can be marked such that the pointer value is read only, e.g.: register struct task_struct *const current asm("e2"); This prevents inadvertent assignment outside of assembly code. This has been available on the MN10300 arch for a while now, and I've also tested it on the FRV arch. Signed-off-by: David Howells <dhowells@xxxxxxxxxx> --- arch/frv/include/asm/current.h | 2 +- arch/microblaze/include/asm/current.h | 2 +- arch/powerpc/include/asm/current.h | 2 +- arch/sparc/include/asm/current.h | 2 +- 4 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/frv/include/asm/current.h b/arch/frv/include/asm/current.h index 86b0274..51bdaf2 100644 --- a/arch/frv/include/asm/current.h +++ b/arch/frv/include/asm/current.h @@ -17,7 +17,7 @@ /* * dedicate GR29 to keeping the current task pointer */ -register struct task_struct *current asm("gr29"); +register struct task_struct *const current asm("gr29"); #define get_current() current diff --git a/arch/microblaze/include/asm/current.h b/arch/microblaze/include/asm/current.h index 29303ed..b824847 100644 --- a/arch/microblaze/include/asm/current.h +++ b/arch/microblaze/include/asm/current.h @@ -21,7 +21,7 @@ /* * Dedicate r31 to keeping the current task pointer */ -register struct task_struct *current asm("r31"); +register struct task_struct *const current asm("r31"); # define get_current() current # endif /* __ASSEMBLY__ */ diff --git a/arch/powerpc/include/asm/current.h b/arch/powerpc/include/asm/current.h index e2c7f06..4ca5126 100644 --- a/arch/powerpc/include/asm/current.h +++ b/arch/powerpc/include/asm/current.h @@ -32,7 +32,7 @@ static inline struct task_struct *get_current(void) /* * We keep `current' in r2 for speed. */ -register struct task_struct *current asm ("r2"); +register struct task_struct *const current asm ("r2"); #endif diff --git a/arch/sparc/include/asm/current.h b/arch/sparc/include/asm/current.h index f04fd6c..9ae8826 100644 --- a/arch/sparc/include/asm/current.h +++ b/arch/sparc/include/asm/current.h @@ -14,7 +14,7 @@ #include <linux/thread_info.h> #ifdef CONFIG_SPARC64 -register struct task_struct *current asm("g4"); +register struct task_struct *const current asm("g4"); #endif #ifdef CONFIG_SPARC32 -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html