[PATCH] dynamic linker: properly handle STT_NOTYPE symbols

[Waldemar Kozaczuk]

Some ELF files define global variables symbols with STT_NOTYPE
like in this example:

13030: 000000000243b390 0 NOTYPE GLOBAL DEFAULT 13 v8_Default_embedded_blob_size_
13136: 0000000002d09db8 0 NOTYPE GLOBAL DEFAULT 24 v8_Default_embedded_blob_

Currently OSv dynamic linker will resolve such symbols at the relative
offset as specified by st_value and cause page fault. This patch fixes
this logic by correctly adding the base of the ELF to the st_value.

This patch effectively makes it possibly to run latest Node.JS 12 and 14
on OSv.

Signed-off-by: Waldemar Kozaczuk <jwkoz...@gmail.com>
---
core/elf.cc | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/core/elf.cc b/core/elf.cc
index 94e14b07..7c63bbfc 100644
--- a/core/elf.cc
+++ b/core/elf.cc
@@ -91,7 +91,7 @@ void* symbol_module::relocated_addr() const
}
switch (symbol_type(*symbol)) {
case STT_NOTYPE:
- return reinterpret_cast<void*>(symbol->st_value);
+ return reinterpret_cast<void*>(base + symbol->st_value);
break;
case STT_OBJECT:
case STT_FUNC:
--
2.30.2

[Nadav Har'El]

So, is this exactly the same as STT_OBJECT and STT_FUNC below? I think the reinterpret_cast doesn't change anything.

So can you merge it with the STT_OBJECT / STT_FUNC below?

         break;
     case STT_OBJECT:
     case STT_FUNC:
--
2.30.2

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[Waldemar Kozaczuk]

Some ELF files define global variables symbols with STT_NOTYPE
like in this example:

13030: 000000000243b390 0 NOTYPE GLOBAL DEFAULT 13 v8_Default_embedded_blob_size_
13136: 0000000002d09db8 0 NOTYPE GLOBAL DEFAULT 24 v8_Default_embedded_blob_

Currently OSv dynamic linker will resolve such symbols at the relative
offset as specified by st_value and cause page fault. This patch fixes
this logic by correctly adding the base of the ELF to the st_value.

This patch effectively makes it possibly to run latest Node.JS 12 and 14
on OSv.

Signed-off-by: Waldemar Kozaczuk <jwkoz...@gmail.com>
---

core/elf.cc | 2 --
1 file changed, 2 deletions(-)

diff --git a/core/elf.cc b/core/elf.cc
index 94e14b07..3cf1f873 100644
--- a/core/elf.cc
+++ b/core/elf.cc
@@ -91,8 +91,6 @@ void* symbol_module::relocated_addr() const

}
switch (symbol_type(*symbol)) {
case STT_NOTYPE:
- return reinterpret_cast<void*>(symbol->st_value);

- break;
case STT_OBJECT:
case STT_FUNC:
return base + symbol->st_value;
--
2.30.2

[Commit Bot]

From: Waldemar Kozaczuk <jwkoz...@gmail.com>
Committer: Waldemar Kozaczuk <jwkoz...@gmail.com>
Branch: master

dynamic linker: properly handle STT_NOTYPE symbols

Some ELF files define global variables symbols with STT_NOTYPE
like in this example:

13030: 000000000243b390 0 NOTYPE GLOBAL DEFAULT 13 v8_Default_embedded_blob_size_
13136: 0000000002d09db8 0 NOTYPE GLOBAL DEFAULT 24 v8_Default_embedded_blob_

Currently OSv dynamic linker will resolve such symbols at the relative
offset as specified by st_value and cause page fault. This patch fixes
this logic by correctly adding the base of the ELF to the st_value.

This patch effectively makes it possibly to run latest Node.JS 12 and 14
on OSv.

Signed-off-by: Waldemar Kozaczuk <jwkoz...@gmail.com>

---

diff --git a/core/elf.cc b/core/elf.cc