[Xen-devel] [PATCH] tools/livepatch: recognize functions in livepatch.ignore.functions

[elena.ufimtseva@xxxxxxxxxx]

From: Elena Ufimtseva <elena.ufimtseva@xxxxxxxxxx>

It is expected that the symbol has type STT_FUNC in livpatch.ignore.functions
sections, but it is incorrect and results in functions not to be ignored.
To actually ignore functions in livepatch.ignore.functions section, attempt to
find the symbol of type STT_FUNC by its name.

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@xxxxxxxxxx>
---
 create-diff-object.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/create-diff-object.c b/create-diff-object.c
index 82f777e..7e845da 100644
--- a/create-diff-object.c
+++ b/create-diff-object.c
@@ -859,6 +859,7 @@ static void kpatch_mark_ignored_functions_same(struct 
kpatch_elf *kelf)
 {
        struct section *sec;
        struct rela *rela;
+       struct symbol *strsym;
 
        sec = find_section_by_name(&kelf->sections, 
".livepatch.ignore.functions");
        if (!sec)
@@ -867,8 +868,30 @@ static void kpatch_mark_ignored_functions_same(struct 
kpatch_elf *kelf)
        list_for_each_entry(rela, &sec->rela->relas, list) {
                if (!rela->sym->sec)
                        ERROR("expected bundled symbol");
-               if (rela->sym->type != STT_FUNC)
-                       ERROR("expected function symbol");
+               if (rela->sym->type != STT_FUNC) {
+                       log_debug("expected function symbol and we have %d, 
name %s", rela->sym->type, rela->sym->name);
+                       if (rela->string) {
+                               log_debug(", rela string %s\n", rela->string);
+                               strsym = find_symbol_by_name(&kelf->symbols, 
rela->string);
+                               if (!strsym)
+                                       ERROR("can't find %s symbol to 
ignore\n", rela->string);
+                               else {
+                                       if (strsym->type != STT_FUNC)
+                                               ERROR("symbol %s is not 
function to ignore\n", strsym->name);
+                                       else {
+                                               strsym->status = SAME;
+                                               strsym->sec->status = SAME;
+                                               if (strsym->sec->secsym)
+                                                       
strsym->sec->secsym->status = SAME;
+                                               if (strsym->sec->rela)
+                                                       
strsym->sec->rela->status = SAME;
+                                       }
+                               }
+                       }
+                       log_debug("\n");
+                       continue;
+                }
+
                log_normal("ignoring function: %s\n", rela->sym->name);
                if (rela->sym->status != CHANGED)
                        log_normal("NOTICE: no change detected in function %s, 
unnecessary KPATCH_IGNORE_FUNCTION()?\n", rela->sym->name);
-- 
2.11.0


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