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Commit f419e6f6 authored by Zhigang Lu's avatar Zhigang Lu Committed by Chris Metcalf
Browse files

tile: define a macro ktext_writable_addr to get writable kernel text address 



It is used by kgdb, ftrace, kprobe and jump label, so we factor
this out into a helper routine.

Reviewed-by: default avatarChris Metcalf <cmetcalf@ezchip.com>
Signed-off-by: default avatarZhigang Lu <zlu@ezchip.com>
Signed-off-by: default avatarChris Metcalf <cmetcalf@ezchip.com>
parent 9f9499ae

arch/tile/include/asm/page.h

+10 −0
Original line number Diff line number Diff line
@@ -319,6 +319,16 @@ static inline int pfn_valid(unsigned long pfn) 
#define virt_to_page(kaddr) pfn_to_page(kaddr_to_pfn((void *)(kaddr)))

#define page_to_virt(page) pfn_to_kaddr(page_to_pfn(page))



/*

 * The kernel text is mapped at MEM_SV_START as read-only.  To allow

 * modifying kernel text, it is also mapped at PAGE_OFFSET as read-write.

 * This macro converts a kernel address to its writable kernel text mapping,

 * which is used to modify the text code on a running kernel by kgdb,

 * ftrace, kprobe, jump label, etc.

 */

#define ktext_writable_addr(kaddr) \

	((unsigned long)(kaddr) - MEM_SV_START + PAGE_OFFSET)



struct mm_struct;

extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);

extern pte_t *virt_to_kpte(unsigned long kaddr);

arch/tile/kernel/ftrace.c

+1 −1
Original line number Diff line number Diff line
@@ -117,7 +117,7 @@ static int ftrace_modify_code(unsigned long pc, unsigned long old, 
		return -EINVAL;



	/* Operate on writable kernel text mapping. */

	pc_wr = pc - MEM_SV_START + PAGE_OFFSET;

	pc_wr = ktext_writable_addr(pc);



	if (probe_kernel_write((void *)pc_wr, &new, MCOUNT_INSN_SIZE))

		return -EPERM;

arch/tile/kernel/kgdb.c

+1 −1
Original line number Diff line number Diff line
@@ -164,7 +164,7 @@ static unsigned long writable_address(unsigned long addr) 
	unsigned long ret = 0;



	if (core_kernel_text(addr))

		ret = addr - MEM_SV_START + PAGE_OFFSET;

		ret = ktext_writable_addr(addr);

	else if (is_module_text_address(addr))

		ret = addr;

	else

arch/tile/kernel/kprobes.c

+2 −2
Original line number Diff line number Diff line
@@ -116,7 +116,7 @@ void __kprobes arch_arm_kprobe(struct kprobe *p) 
	unsigned long addr_wr;



	/* Operate on writable kernel text mapping. */

	addr_wr = (unsigned long)p->addr - MEM_SV_START + PAGE_OFFSET;

	addr_wr = ktext_writable_addr(p->addr);



	if (probe_kernel_write((void *)addr_wr, &breakpoint_insn,

		sizeof(breakpoint_insn)))
@@ -131,7 +131,7 @@ void __kprobes arch_disarm_kprobe(struct kprobe *kp) 
	unsigned long addr_wr;



	/* Operate on writable kernel text mapping. */

	addr_wr = (unsigned long)kp->addr - MEM_SV_START + PAGE_OFFSET;

	addr_wr = ktext_writable_addr(kp->addr);



	if (probe_kernel_write((void *)addr_wr, &kp->opcode,

		sizeof(kp->opcode)))