added auxv to elf stack setup

the needed ones for rtdl; AT_NULL, AT_PHDR, AT_ENTRY, AT_PHNUM, AT_PHENT
This commit is contained in:
Matheus
2022-08-16 22:06:18 -03:00
parent df2e7b1c34
commit fc6d0000c5
3 changed files with 66 additions and 21 deletions
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+6
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@@ -28,6 +28,12 @@
#define STACK_TOP 0x800000000000
#define AT_NULL 0
#define AT_PHDR 3
#define AT_PHENT 4
#define AT_PHNUM 5
#define AT_ENTRY 9
typedef struct{
uint32_t magic;
uint8_t bits;
+60 -21
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@@ -11,8 +11,8 @@ typedef struct{
} auxv64_t;
typedef struct {
auxv64_t phdr;
auxv64_t null;
} auxv64_list;
static size_t phflagtommuflag(size_t phflags){
@@ -51,13 +51,13 @@ static bool check_header64(elf_header64* header){
}
static void* stacksetup(char* interp, char** argv, char** env){
static void* stacksetup(char* interp, char** argv, char** env, elf_header64 header, elf_ph64* phs){
size_t argc = 0;
size_t envc = 0;
size_t initialsize = 0;
size_t argdatasize = 0;
size_t envdatasize = 0;
size_t auxvsize = 8;
size_t auxvsize = 5*8; // FIXME better way of keeping track of this
while(argv[argc]){
argdatasize += strlen(argv[argc]) + 1;
@@ -81,35 +81,61 @@ static void* stacksetup(char* interp, char** argv, char** env){
initialsize += argc*sizeof(char*); //args
initialsize += envc*sizeof(char*); //envs
initialsize += 2*sizeof(char**); //argv envp
initialsize += sizeof(size_t); //argc
// allocate memory for the initial section of the stack
if(!vmm_allocnowat(STACK_TOP - initialsize, ARCH_MMU_MAP_READ | ARCH_MMU_MAP_WRITE | ARCH_MMU_MAP_NOEXEC | ARCH_MMU_MAP_USER, initialsize)) return NULL;
// XXX demand alloc the non initialised stack pages
if(!vmm_allocnowat(STACK_TOP - initialsize - PAGE_SIZE*200, ARCH_MMU_MAP_READ | ARCH_MMU_MAP_WRITE | ARCH_MMU_MAP_NOEXEC | ARCH_MMU_MAP_USER, initialsize + PAGE_SIZE*200)) return NULL;
// get the addresses to copy the data to
char* argdatastart = STACK_TOP - argdatasize;
elf_ph64* phdrdatastart = STACK_TOP - header.ph_count * header.ph_size;
char* argdatastart = (void*) phdrdatastart - argdatasize;
char* envdatastart = argdatastart - envdatasize;
// auxvstart will be aligned
void* auxvstart = (void*)(((uintptr_t)envdatastart & (~0xF)) - auxvsize);
auxv64_t* auxvstart = (void*)(((uintptr_t)envdatastart & (~0xF)) - auxvsize);
// count + 1 because of a null entry
char** envstart = auxvstart - (envc + 1)*sizeof(char*);
char** envstart = (void*)auxvstart - (envc + 1)*sizeof(char*);
char** argstart = (void*)envstart - (argc + 1)*sizeof(char*);
if(interp)
--argstart;
char*** envpptr = (void*)argstart - sizeof(char**);
char*** argvptr = (void*)envpptr - sizeof(char**);
size_t* argcptr = (void*)argvptr - sizeof(size_t);
// XXX auxv
size_t* argcptr = (void*)argstart - sizeof(size_t);
// auxv
// AT_PHDR
auxvstart->a_type = AT_PHDR;
auxvstart->a_val = (uint64_t)phdrdatastart;
auxvstart++;
memcpy(phdrdatastart, phs, header.ph_count * header.ph_size);
// AT_PHENT
auxvstart->a_type = AT_PHENT;
auxvstart->a_val = header.ph_size;
auxvstart++;
// AT_PHNUM
auxvstart->a_type = AT_PHNUM;
auxvstart->a_val = header.ph_count;
// AT_ENTRY
auxvstart->a_type = AT_ENTRY;
auxvstart->a_val = header.entry;
auxvstart++;
// AT_NULL
auxvstart->a_type = AT_NULL;
// copy the data
*envpptr = envstart;
*argvptr = argstart;
if(interp){
strcpy(argdatastart, interp);
@@ -147,7 +173,9 @@ static void* stacksetup(char* interp, char** argv, char** env){
int elf_load(thread_t* thread, vnode_t* node, char** argv, char** env){
elf_header64 header;
elf_ph64 ph;
elf_header64 progheader;
elf_ph64 ph;
int err = 0;
int readc = vfs_read(&err, node, &header, sizeof(elf_header64), 0);
char* interp = NULL;
@@ -159,8 +187,13 @@ int elf_load(thread_t* thread, vnode_t* node, char** argv, char** env){
if(readc != sizeof(elf_header64) || (!check_header64(&header)))
return EINVAL;
progheader = header; // incase an interpreter exists
// find out if this needs an interpreter
// and also save the executable's program headers
// for auxv
elf_ph64 progphs[header.ph_count];
for(size_t currentph = 0; currentph < header.ph_count; ++currentph){
readc = vfs_read(&err, node, &ph, header.ph_size, header.ph_pos + currentph*header.ph_size);
@@ -169,10 +202,14 @@ int elf_load(thread_t* thread, vnode_t* node, char** argv, char** env){
if(readc != header.ph_size)
return EINVAL;
memcpy(progphs+currentph, &ph, sizeof(elf_ph64));
if(ph.type == PH_TYPE_INTERPRETER){
// load the name and elf header of the interpreter
progheader = header;
char* interp = alloc(ph.fsize + 1);
if(!interp)
return ENOMEM;
@@ -204,8 +241,6 @@ int elf_load(thread_t* thread, vnode_t* node, char** argv, char** env){
goto _fail;
}
break;
}
}
@@ -265,7 +300,11 @@ int elf_load(thread_t* thread, vnode_t* node, char** argv, char** env){
}
void* stack = stacksetup(interp, argv, env);
void* stack = stacksetup(interp, argv, env, progheader, progphs);
arch_regs_setupuser(thread->regs, (void*)header.entry, stack, true);