Commit 93f067f6 authored by Catalin Marinas's avatar Catalin Marinas
Browse files

arm64: mte: Allow {set,get}_tagged_addr_ctrl() on non-current tasks 



In preparation for ptrace() access to the prctl() value, allow calling
these functions on non-current tasks.

Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
parent 39d08e83

arch/arm64/include/asm/mte.h

+4 −4
Original line number Diff line number Diff line
@@ -23,8 +23,8 @@ void mte_copy_page_tags(void *kto, const void *kfrom); 
void flush_mte_state(void);

void mte_thread_switch(struct task_struct *next);

void mte_suspend_exit(void);

long set_mte_ctrl(unsigned long arg);

long get_mte_ctrl(void);

long set_mte_ctrl(struct task_struct *task, unsigned long arg);

long get_mte_ctrl(struct task_struct *task);



#else
@@ -46,11 +46,11 @@ static inline void mte_thread_switch(struct task_struct *next) 
static inline void mte_suspend_exit(void)

{

}

static inline long set_mte_ctrl(unsigned long arg)

static inline long set_mte_ctrl(struct task_struct *task, unsigned long arg)

{

	return 0;

}

static inline long get_mte_ctrl(void)

static inline long get_mte_ctrl(struct task_struct *task)

{

	return 0;

}

arch/arm64/include/asm/processor.h

+4 −4
Original line number Diff line number Diff line
@@ -319,10 +319,10 @@ extern void __init minsigstksz_setup(void); 


#ifdef CONFIG_ARM64_TAGGED_ADDR_ABI

/* PR_{SET,GET}_TAGGED_ADDR_CTRL prctl */

long set_tagged_addr_ctrl(unsigned long arg);

long get_tagged_addr_ctrl(void);

#define SET_TAGGED_ADDR_CTRL(arg)	set_tagged_addr_ctrl(arg)

#define GET_TAGGED_ADDR_CTRL()		get_tagged_addr_ctrl()

long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg);

long get_tagged_addr_ctrl(struct task_struct *task);

#define SET_TAGGED_ADDR_CTRL(arg)	set_tagged_addr_ctrl(current, arg)

#define GET_TAGGED_ADDR_CTRL()		get_tagged_addr_ctrl(current)

#endif



/*

arch/arm64/kernel/mte.c

+12 −6
Original line number Diff line number Diff line
@@ -124,9 +124,10 @@ void mte_suspend_exit(void) 
	update_gcr_el1_excl(current->thread.gcr_user_incl);

}



long set_mte_ctrl(unsigned long arg)

long set_mte_ctrl(struct task_struct *task, unsigned long arg)

{

	u64 tcf0;

	u64 gcr_incl = (arg & PR_MTE_TAG_MASK) >> PR_MTE_TAG_SHIFT;



	if (!system_supports_mte())

		return 0;
@@ -145,22 +146,27 @@ long set_mte_ctrl(unsigned long arg) 
		return -EINVAL;

	}



	if (task != current) {

		task->thread.sctlr_tcf0 = tcf0;

		task->thread.gcr_user_incl = gcr_incl;

	} else {

		set_sctlr_el1_tcf0(tcf0);

	set_gcr_el1_excl((arg & PR_MTE_TAG_MASK) >> PR_MTE_TAG_SHIFT);

		set_gcr_el1_excl(gcr_incl);

	}



	return 0;

}



long get_mte_ctrl(void)

long get_mte_ctrl(struct task_struct *task)

{

	unsigned long ret;



	if (!system_supports_mte())

		return 0;



	ret = current->thread.gcr_user_incl << PR_MTE_TAG_SHIFT;

	ret = task->thread.gcr_user_incl << PR_MTE_TAG_SHIFT;



	switch (current->thread.sctlr_tcf0) {

	switch (task->thread.sctlr_tcf0) {

	case SCTLR_EL1_TCF0_NONE:

		return PR_MTE_TCF_NONE;

	case SCTLR_EL1_TCF0_SYNC:

arch/arm64/kernel/process.c

+10 −8
Original line number Diff line number Diff line
@@ -641,11 +641,12 @@ void arch_setup_new_exec(void) 
 */

static unsigned int tagged_addr_disabled;



long set_tagged_addr_ctrl(unsigned long arg)

long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg)

{

	unsigned long valid_mask = PR_TAGGED_ADDR_ENABLE;

	struct thread_info *ti = task_thread_info(task);



	if (is_compat_task())

	if (is_compat_thread(ti))

		return -EINVAL;



	if (system_supports_mte())
@@ -661,25 +662,26 @@ long set_tagged_addr_ctrl(unsigned long arg) 
	if (arg & PR_TAGGED_ADDR_ENABLE && tagged_addr_disabled)

		return -EINVAL;



	if (set_mte_ctrl(arg) != 0)

	if (set_mte_ctrl(task, arg) != 0)

		return -EINVAL;



	update_thread_flag(TIF_TAGGED_ADDR, arg & PR_TAGGED_ADDR_ENABLE);

	update_ti_thread_flag(ti, TIF_TAGGED_ADDR, arg & PR_TAGGED_ADDR_ENABLE);



	return 0;

}



long get_tagged_addr_ctrl(void)

long get_tagged_addr_ctrl(struct task_struct *task)

{

	long ret = 0;

	struct thread_info *ti = task_thread_info(task);



	if (is_compat_task())

	if (is_compat_thread(ti))

		return -EINVAL;



	if (test_thread_flag(TIF_TAGGED_ADDR))

	if (test_ti_thread_flag(ti, TIF_TAGGED_ADDR))

		ret = PR_TAGGED_ADDR_ENABLE;



	ret |= get_mte_ctrl();

	ret |= get_mte_ctrl(task);



	return ret;

}

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