powerpc/lib/code-patching: refactor patch_instruction()

patch_instruction() uses almost the same sequence as
__patch_instruction()

This patch refactor it so that patch_instruction() uses
__patch_instruction() instead of duplicating code.

BugLink: https://bugs.launchpad.net/bugs/1822870
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
(cherry picked from commit 8cf4c05712f04a405f0dacebcca8f042b391694a)
Signed-off-by: Manoj Iyer <manoj.iyer@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 096d4e4d31e6359801f15d9b38f88d1ab275d0fc..e1c58937281fd87cbb06aff5384fe77741063884 100644 (file)
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -23,19 +23,26 @@
 #include <asm/code-patching.h>
 #include <asm/setup.h>
 
-static int __patch_instruction(unsigned int *addr, unsigned int instr)
+static int __patch_instruction(unsigned int *exec_addr, unsigned int instr,
+                              unsigned int *patch_addr)
 {
        int err;
 
-       __put_user_size(instr, addr, 4, err);
+       __put_user_size(instr, patch_addr, 4, err);
        if (err)
                return err;
 
-       asm ("dcbst 0, %0; sync; icbi 0,%0; sync; isync" :: "r" (addr));
+       asm ("dcbst 0, %0; sync; icbi 0,%1; sync; isync" :: "r" (patch_addr),
+                                                           "r" (exec_addr));
 
        return 0;
 }
 
+static int raw_patch_instruction(unsigned int *addr, unsigned int instr)
+{
+       return __patch_instruction(addr, instr, addr);
+}
+
 #ifdef CONFIG_STRICT_KERNEL_RWX
 static DEFINE_PER_CPU(struct vm_struct *, text_poke_area);
 
@@ -138,7 +145,7 @@ static inline int unmap_patch_area(unsigned long addr)
 int patch_instruction(unsigned int *addr, unsigned int instr)
 {
        int err;
-       unsigned int *dest = NULL;
+       unsigned int *patch_addr = NULL;
        unsigned long flags;
        unsigned long text_poke_addr;
        unsigned long kaddr = (unsigned long)addr;
@@ -149,7 +156,7 @@ int patch_instruction(unsigned int *addr, unsigned int instr)
         * to allow patching. We just do the plain old patching
         */
        if (!this_cpu_read(*PTRRELOC(&text_poke_area)))
-               return __patch_instruction(addr, instr);
+               return raw_patch_instruction(addr, instr);
 
        local_irq_save(flags);
 
@@ -159,17 +166,10 @@ int patch_instruction(unsigned int *addr, unsigned int instr)
                goto out;
        }
 
-       dest = (unsigned int *)(text_poke_addr) +
+       patch_addr = (unsigned int *)(text_poke_addr) +
                        ((kaddr & ~PAGE_MASK) / sizeof(unsigned int));
 
-       /*
-        * We use __put_user_size so that we can handle faults while
-        * writing to dest and return err to handle faults gracefully
-        */
-       __put_user_size(instr, dest, 4, err);
-       if (!err)
-               asm ("dcbst 0, %0; sync; icbi 0,%0; icbi 0,%1; sync; isync"
-                       ::"r" (dest), "r"(addr));
+       __patch_instruction(addr, instr, patch_addr);
 
        err = unmap_patch_area(text_poke_addr);
        if (err)
@@ -184,7 +184,7 @@ out:
 
 int patch_instruction(unsigned int *addr, unsigned int instr)
 {
-       return __patch_instruction(addr, instr);
+       return raw_patch_instruction(addr, instr);
 }
 
 #endif /* CONFIG_STRICT_KERNEL_RWX */