Merge pull request #913 from criblio/feat-terraform-test

Support Go static stripped executables
criblio · May 6, 2022 · 311a77e · 311a77e
2 parents f1cf9d4 + 03fd6ff
commit 311a77e
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Showing 11 changed files with 531 additions and 202 deletions.
diff --git a/src/scopeelf.c b/src/scopeelf.c
@@ -11,9 +11,6 @@
 #include "fn.h"
 #include "scopeelf.h"
 
-#define GOPCLNTAB_MAGIC_112 0xfffffffb
-#define GOPCLNTAB_MAGIC_116 0xfffffffa
-
 void
 freeElf(char *buf, size_t len)
 {
@@ -336,123 +333,6 @@ getSymbol(const char *buf, char *sname)
     return (void *)symaddr;
 }
 
-void *
-getGoSymbol(const char *buf, char *sname)
-{
-    int i;
-    Elf64_Addr symaddr = 0;
-    Elf64_Ehdr *ehdr;
-    Elf64_Shdr *sections;
-    const char *section_strtab = NULL;
-    const char *sec_name = NULL;
-
-    if (!buf || !sname) return NULL;
-
-    ehdr = (Elf64_Ehdr *)buf;
-    sections = (Elf64_Shdr *)((char *)buf + ehdr->e_shoff);
-    section_strtab = (char *)buf + sections[ehdr->e_shstrndx].sh_offset;
-
-    for (i = 0; i < ehdr->e_shnum; i++) {
-        sec_name = section_strtab + sections[i].sh_name;
-        if (scope_strcmp(".gopclntab", sec_name) == 0) {
-            const void *pclntab_addr = buf + sections[i].sh_offset;
-            /*
-            Go symbol table is stored in the .gopclntab section
-            More info: https://docs.google.com/document/d/1lyPIbmsYbXnpNj57a261hgOYVpNRcgydurVQIyZOz_o/pub
-            */
-            uint32_t magic = *((const uint32_t *)(pclntab_addr));
-            if (magic == GOPCLNTAB_MAGIC_112) {
-                uint64_t sym_count      = *((const uint64_t *)(pclntab_addr + 8));
-                const void *symtab_addr = pclntab_addr + 16;
-
-                for(i=0; i<sym_count; i++) {
-                    uint64_t sym_addr     = *((const uint64_t *)(symtab_addr));
-                    uint64_t func_offset  = *((const uint64_t *)(symtab_addr + 8));
-                    uint32_t name_offset  = *((const uint32_t *)(pclntab_addr + func_offset + 8));
-                    const char *func_name = (const char *)(pclntab_addr + name_offset);
-
-                    if (scope_strcmp(sname, func_name) == 0) {
-                        symaddr = sym_addr;
-                        scopeLog(CFG_LOG_TRACE, "symbol found %s = 0x%08lx\n", func_name, sym_addr);
-                        break;
-                    }
-                    symtab_addr += 16;
-                }
-            } else if (magic == GOPCLNTAB_MAGIC_116) {
-                uint64_t sym_count      = *((const uint64_t *)(pclntab_addr + 8));
-                uint64_t funcnametab_offset = *((const uint64_t *)(pclntab_addr + (3 * 8)));
-                uint64_t pclntab_offset = *((const uint64_t *)(pclntab_addr + (7 * 8)));
-                const void *symtab_addr = pclntab_addr + pclntab_offset;
-                for (i = 0; i < sym_count; i++) {
-                    uint64_t sym_addr = *((const uint64_t *)(symtab_addr));
-                    uint64_t func_offset = *((const uint64_t *)(symtab_addr + 8));
-                    uint32_t name_offset = *((const uint32_t *)(pclntab_addr + pclntab_offset + func_offset + 8));
-                    const char *func_name = (const char *)(pclntab_addr + funcnametab_offset + name_offset);
-                    if (scope_strcmp(sname, func_name) == 0) {
-                        symaddr = sym_addr;
-                        scopeLog(CFG_LOG_TRACE, "symbol found %s = 0x%08lx\n", func_name, sym_addr);
-                        break;
-                    }
-                    symtab_addr += 16;
-                }
-            } else {
-                scopeLog(CFG_LOG_DEBUG, "Invalid header in .gopclntab");
-                break;
-            }
-            break;
-        }
-    }
-
-    return (void *)symaddr;
-}
-
-void *
-getGoVersionAddr(const char* buf)
-{
-    int i;
-    Elf64_Ehdr *ehdr;
-    Elf64_Shdr *sections;
-    const char *section_strtab = NULL;
-    const char *sec_name;
-    const char *sec_data;
-
-    ehdr = (Elf64_Ehdr *)buf;
-    sections = (Elf64_Shdr *)(buf + ehdr->e_shoff);
-    section_strtab = (char *)buf + sections[ehdr->e_shstrndx].sh_offset;
-    const char magic[0xe] = "\xff Go buildinf:";
-    void *go_build_ver_addr = NULL;
-
-    for (i = 0; i < ehdr->e_shnum; i++) {
-        sec_name = section_strtab + sections[i].sh_name;
-        sec_data = (const char *)buf + sections[i].sh_offset;
-        // Since go1.13, the .go.buildinfo section has been added to
-        // identify where runtime.buildVersion exists, for the case where
-        // go apps have been stripped of their symbols.
-
-        // offset into sec_data     field contents
-        // -----------------------------------------------------------
-        // 0x0                      build info magic = "\xff Go buildinf:"
-        // 0xe                      binary ptrSize
-        // 0xf                      endianness
-        // 0x10                     pointer to string runtime.buildVersion
-        // 0x10 + ptrSize           pointer to runtime.modinfo
-        // 0x10 + 2 * ptr size      pointer to build flags
-
-        if (!scope_strcmp(sec_name, ".go.buildinfo") &&
-            (sections[i].sh_size >= 0x18) &&
-            (!scope_memcmp(&sec_data[0], magic, sizeof(magic))) &&
-            (sec_data[0xe] == 0x08) &&  // 64 bit executables only
-            (sec_data[0xf] == 0x00)) {  // little-endian
-
-            uint64_t *addressPtr = (uint64_t*)&sec_data[0x10];
-
-            go_build_ver_addr = (void*)*addressPtr;
-        }
-    }
-
-    return go_build_ver_addr;
-}
-
 bool
 is_static(char *buf)
 {

diff --git a/src/scopeelf.h b/src/scopeelf.h
@@ -26,8 +26,6 @@ int doGotcha(struct link_map *, got_list_t *, Elf64_Rela *, Elf64_Sym *, char *,
 int getElfEntries(struct link_map *, Elf64_Rela **, Elf64_Sym **, char **, int *rsz);
 Elf64_Shdr* getElfSection(char *, const char *);
 void * getSymbol(const char *, char *);
-void * getGoSymbol(const char *, char *);
-void * getGoVersionAddr(const char*);
 bool is_static(char *);
 bool is_go(char *);
 bool is_musl(char *);