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authorLinus Torvalds <torvalds@linux-foundation.org>2016-01-18 21:57:18 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2016-01-18 21:57:18 +0100
commitd05d82f7110b08fd36178a641b69a1f206e1142b (patch)
treea274bb136f5ed336fb7a12bb86ea24cc5daffdc9 /arch/tile/include/asm/page.h
parentMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/egt... (diff)
parentnuma: remove stale node_has_online_mem() define (diff)
downloadlinux-d05d82f7110b08fd36178a641b69a1f206e1142b.tar.xz
linux-d05d82f7110b08fd36178a641b69a1f206e1142b.zip
Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile
Pull arch/tile updates from Chris Metcalf: "This is a grab bag of changes that includes some NOHZ and context-tracking related changes, some debugging improvements, JUMP_LABEL support, and some fixes for tilepro allmodconfig support. We also remove the now-unused node_has_online_mem() definitions both for tile's asm/topology.h as well as in linux/topology.h itself" * git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: numa: remove stale node_has_online_mem() define arch/tile: move user_exit() to early kernel entry sequence tile: fix bug in setting PT_FLAGS_DISABLE_IRQ on kernel entry tile: fix tilepro casts for readl, writel, etc tile: fix a -Wframe-larger-than warning tile: include the syscall number in the backtrace MAINTAINERS: add git URL for tile arch/tile: adopt prepare_exit_to_usermode() model from x86 tile/jump_label: add jump label support for TILE-Gx tile: define a macro ktext_writable_addr to get writable kernel text address
Diffstat (limited to 'arch/tile/include/asm/page.h')
-rw-r--r--arch/tile/include/asm/page.h10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/tile/include/asm/page.h b/arch/tile/include/asm/page.h
index 8eca6a0e1762..498a5f71245d 100644
--- a/arch/tile/include/asm/page.h
+++ b/arch/tile/include/asm/page.h
@@ -321,6 +321,16 @@ 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);