diff options
| author | Zhigang Lu <zlu@ezchip.com> | 2015-09-30 04:53:47 +0300 |
|---|---|---|
| committer | Chris Metcalf <cmetcalf@ezchip.com> | 2016-01-04 23:09:31 +0300 |
| commit | f419e6f63c5afea00d7c17ebf54f2d265f5c4d7e (patch) | |
| tree | c9c49f97a3a3abd0c55fce3f41fe71ef0125d3af /arch | |
| parent | 9f9499ae8e6415cefc4fe0a96ad0e27864353c89 (diff) | |
| download | linux-f419e6f63c5afea00d7c17ebf54f2d265f5c4d7e.tar.xz | |
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: Chris Metcalf <cmetcalf@ezchip.com>
Signed-off-by: Zhigang Lu <zlu@ezchip.com>
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/tile/include/asm/page.h | 10 | ||||
| -rw-r--r-- | arch/tile/kernel/ftrace.c | 2 | ||||
| -rw-r--r-- | arch/tile/kernel/kgdb.c | 2 | ||||
| -rw-r--r-- | arch/tile/kernel/kprobes.c | 4 |
4 files changed, 14 insertions, 4 deletions
diff --git a/arch/tile/include/asm/page.h b/arch/tile/include/asm/page.h index a213a8d84a95..5cee2cbff2b1 100644 --- a/arch/tile/include/asm/page.h +++ b/arch/tile/include/asm/page.h @@ -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); diff --git a/arch/tile/kernel/ftrace.c b/arch/tile/kernel/ftrace.c index 0c0996175b1e..4180ccdf9cd0 100644 --- a/arch/tile/kernel/ftrace.c +++ b/arch/tile/kernel/ftrace.c @@ -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; diff --git a/arch/tile/kernel/kgdb.c b/arch/tile/kernel/kgdb.c index ff5335ae050d..a506c2c28943 100644 --- a/arch/tile/kernel/kgdb.c +++ b/arch/tile/kernel/kgdb.c @@ -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 diff --git a/arch/tile/kernel/kprobes.c b/arch/tile/kernel/kprobes.c index f8a45c51e9e4..c68694bb1ad2 100644 --- a/arch/tile/kernel/kprobes.c +++ b/arch/tile/kernel/kprobes.c @@ -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))) |