ldelf.c

T-kernel 的extension源代码

/*
 *----------------------------------------------------------------------
 *    T-Kernel / Standard Extension
 *
 *    Copyright (C) 2006 by Ken Sakamura. All rights reserved.
 *    T-Kernel / Standard Extension is distributed 
 *      under the T-License for T-Kernel / Standard Extension.
 *----------------------------------------------------------------------
 *
 *    Version:   1.00.00
 *    Released by T-Engine Forum(http://www.t-engine.org) at 2006/8/11.
 *
 *----------------------------------------------------------------------
 */

/*
 *	ldelf.c (memory)
 *
 *	ELF format program loading (VR4131 Virtual storage version)
 *
 *	Supports the following loading formats:
 *	* On-demand loading
 *	* Global loading/not relocated
 *	* Global loading/relocated
 */

#include "segmgr.h"
#include <cnvend.h>

#ifdef DEBUG
#  define _ER_REC(n)		( E_REC | (n) )
#else
#  define _ER_REC(n)		( E_REC )
#endif

#define	LINK_ADDR		0x00100000	/* Link address */
#define TSD_GEI_SYM_M1		(-1)
#define TSD_RL1_MSK_0XFC000000	0xfc000000U
#define TSD_RL1_MSK_0XF0000000	0xf0000000U
#define TSD_RL1_MSK_0XFFFF0000	0xffff0000U
#define TSD_RL1_MSK_0X03E00000	0x03e00000U
#define TSD_RL1_MSK_0X001F0000	0x001f0000U
#define TSD_RL1_MSK_0X03E0	0x03e0U
#define TSD_RL1_MSK_0X001F	0x001fU
#define TSD_RL1_MSK_0XFC00	0xfc00U
#define TSD_RL1_SFT_11		11U
#define TSD_RL1_SFT_13		13U
#define TSD_RL1_SFT_21		21U
#define TSD_RL1_SFT_23		23U
#define TSD_GEI_VAL_2		2
#define TSD_LDE_ERR_1		1
#define TSD_LDE_ERR_2		2
#define TSD_LDE_ERR_3		3
#define TSD_LDE_ERR_4		4
#define TSD_LDE_ERR_5		5
#define TSD_LDE_ERR_6		6
#define TSD_LDE_ERR_7		7
#define TSD_LDE_ERR_8		8
#define TSD_LDE_ERR_9		9
#define TSD_LDE_ERR_10		10
#define TSD_LDE_ERR_11		11
#define TSD_LDE_ERR_12		12
#define TSD_LDE_ERR_13		13
#define TSD_LDE_ERR_14		14
#define TSD_LDE_ERR_15		15
#define TSD_LDE_ERR_16		16
#define TSD_LDE_ERR_17		17
#define TSD_RL1_MSK_0X03FFFFFF	0x03ffffffU
#define TSD_RL1_SFT_MCR		((W)((UW)addend << 6) >> 4)
#define TSD_RL1_SFT_2		2U
#define TSD_RL1_SFT_16		16U
#define TSD_RL1_MSK_0XFFFF	0xffffU
#define TSD_RL1_MSK_0X0000FFFF	0x0000ffffU

/* Format checking for each supported model */
#define CHK_ELFDATA(n)		( (n) == ELFDATA2LSB )
#define CHK_ELFMACH(n)		( (n) == EM_MIPS )

/*
 * ELF loading information
 */
typedef struct {
	VB*	text_ladr;	/* text area loading address */
	UW	text_fofs;	/* text area file position */
	UW	text_size;	/* text area size */
	VB*	data_ladr;	/* data area loading address */
	UW	data_fofs;	/* data area file position */
	UW	data_size;	/* data area size */
	VB*	bss_ladr;	/* bss  area first address */
	UW	bss_size;	/* bss  area size */
	UW	stack_size;	/* Stack size */

	UH	text_shndx;	/* text area section number */
	UH	data_shndx;	/* data area section number */
	UH	bss_shndx;	/* bss  area section number */
	UW	rel_text_fofs;	/* File position of text area relocation information */
	UW	rel_text_size;	/* Size of text area relocation information */
	UW	rel_data_fofs;	/* File position of data area relocation information */
	UW	rel_data_size;	/* Size of data area relocation information */

	UW	symtbl_fofs;	/* File position of symbol table */
	UW	symtbl_size;	/* Size of symbol table */
	BOOL	vir_or_off;	/* Virtual address (TRUE) or offset (FALSE) */
	UW	reginf_fofs;	/* File position of register information */
	UW	reginf_size;	/* Size of register information */
	W	gp;		/* gp register value */
} ELF_LoadInfo;

LOCAL ER CheckLoadAddress( ELF_LoadInfo *eli );
LOCAL ER CheckSysLoadAddress( ELF_LoadInfo *eli );
LOCAL ER GetELFLoadInfoShdr( ELF_LoadInfo *eli, Elf32_Ehdr *hdr, POBJ_HDR *pohdr, BzRead *bzr );
LOCAL BOOL HasDynSeg( Elf32_Ehdr *hdr, POBJ_HDR *pohdr, BzRead *bzr );
LOCAL BOOL HasRelSec( Elf32_Ehdr *hdr, POBJ_HDR *pohdr, BzRead *bzr );
LOCAL ER GetELFLoadInfoPhdr( ELF_LoadInfo *eli, Elf32_Ehdr *hdr, POBJ_HDR *pohdr, BzRead *bzr );
LOCAL ER GetELFLoadInfo( ELF_LoadInfo *eli, Elf32_Ehdr *hdr, POBJ_HDR *pohdr, BzRead *bzr, BOOL relsec );
LOCAL ER reloc1( ELF_LoadInfo *eli, POBJ_HDR *pohdr, W rtbl, W rtblsz, W lofs, VB *sect, W sectsz, Elf32_Sym *symtbl, W syment, BzRead *bzr );
LOCAL ER elf_get_gp( POBJ_HDR *pohdr, ELF_LoadInfo *eli, BzRead *bzr );
LOCAL ER elf_relocation( LDINFO *li, ELF_LoadInfo *eli, W lofs, BzRead *bzr );

#ifdef DEBUG
LOCAL void prELFLoadInfo( ELF_LoadInfo *eli )
{
	DEBUG_PRINT(("ELF_LoadInfo\n"));
	DEBUG_PRINT(("\t.text_ladr     = 0x%08x\n",	eli->text_ladr));
	DEBUG_PRINT(("\t.text_fofs     = 0x%08x\n",	eli->text_fofs));
	DEBUG_PRINT(("\t.text_size     = 0x%08x\n",	eli->text_size));
	DEBUG_PRINT(("\t.data_ladr     = 0x%08x\n",	eli->data_ladr));
	DEBUG_PRINT(("\t.data_fofs     = 0x%08x\n",	eli->data_fofs));
	DEBUG_PRINT(("\t.data_size     = 0x%08x\n",	eli->data_size));
	DEBUG_PRINT(("\t.bss_ladr      = 0x%08x\n",	eli->bss_ladr));
	DEBUG_PRINT(("\t.bss_size      = 0x%08x\n",	eli->bss_size));
	DEBUG_PRINT(("\t.stack_size    = %d\n",		eli->stack_size));
	DEBUG_PRINT(("\t.text_shndx    = %d\n",		eli->text_shndx));
	DEBUG_PRINT(("\t.data_shndx    = %d\n",		eli->data_shndx));
	DEBUG_PRINT(("\t.bss_shndx     = %d\n",		eli->bss_shndx));
	DEBUG_PRINT(("\t.rel_text_fofs = 0x%08x\n",	eli->rel_text_fofs));
	DEBUG_PRINT(("\t.rel_text_size = %d\n",		eli->rel_text_size));
	DEBUG_PRINT(("\t.rel_data_fofs = 0x%08x\n",	eli->rel_data_fofs));
	DEBUG_PRINT(("\t.rel_data_size = %d\n",		eli->rel_data_size));
	DEBUG_PRINT(("\t.symtbl_fofs   = 0x%08x\n",	eli->symtbl_fofs));
	DEBUG_PRINT(("\t.symtbl_size   = %d\n",		eli->symtbl_size));
}
#endif

/*
 * Check if the loading address is within a range of the process unique space.
 */
LOCAL ER CheckLoadAddress( ELF_LoadInfo *eli )
{
	ER	err;

	if ( !isLocalSpace(eli->text_ladr)
	  || !isLocalSpace(eli->bss_ladr + eli->bss_size) ) {
		err = _ER_REC(TSD_LDE_ERR_1);
		goto err_ret;
	}

	return E_OK;

err_ret:
	DEBUG_PRINT(("CheckLoadAddress err = %d (%d)\n", err, (UH)err));
	return err;
}

/*
 * Check if the loading address is within a range of system program loading.
 */
LOCAL ER CheckSysLoadAddress( ELF_LoadInfo *eli )
{
	ER	err;

	if ( !isSysLoadSpace(eli->text_ladr)
	  || !isSysLoadSpace(eli->bss_ladr + eli->bss_size) ) {
		err = _ER_REC(TSD_LDE_ERR_1);
		goto err_ret;
	}

	return E_OK;

err_ret:
	DEBUG_PRINT(("CheckSysLoadAddress err = %d (%d)\n", err, (UH)err));
	return err;
}

/*
 * Obtain loading information from ELF section header.
 */
LOCAL ER GetELFLoadInfoShdr( ELF_LoadInfo *eli, Elf32_Ehdr *hdr, POBJ_HDR *pohdr, BzRead *bzr )
{
	Elf32_Shdr	*shdr_buf, *shdr, *p;
	W		n;
	VB		*adr;
	W		symsect = TSD_GEI_SYM_M1;
	ER		err;

	if ( (hdr->e_shentsize < sizeof(Elf32_Shdr)) || (hdr->e_shnum == 0) ) {
		err = _ER_REC(TSD_LDE_ERR_1);
		goto err_ret1;
	}

	/* Buffer for loading section header */
	n = hdr->e_shentsize * hdr->e_shnum;
	shdr_buf = Vmalloc((size_t)n);
	if ( shdr_buf == NULL ) {
		err = E_NOMEM;
		goto err_ret1;
	}

	/* Load section header */
	err = ReadProgFile(pohdr, (W)hdr->e_shoff, (VB*)shdr_buf, n, bzr);
	if ( err < E_OK ) {
		goto err_ret2;
	}

	eli->stack_size = (UW)DefaultStackSize;
	for ( n = (W)hdr->e_shnum, shdr = shdr_buf;
			--n >= 0; shdr = (Elf32_Shdr*)((VB*)shdr + hdr->e_shentsize) ) {

		switch ( shdr->sh_type ) {
		  case SHT_PROGBITS:
			if (( shdr->sh_flags & SHF_ALLOC) == 0U) {
				continue; /* Ignore */
			}
			
			switch ( shdr->sh_flags ) {
			  case SHF_ALLOC|SHF_EXECINSTR:	/* text area */
				if ( eli->text_size != 0U ) {
					err = _ER_REC(TSD_LDE_ERR_2);
					goto err_ret2;
				}
				eli->text_ladr = shdr->sh_addr;
				eli->text_fofs = shdr->sh_offset;
				eli->text_size = shdr->sh_size;
				eli->text_shndx = (UH)(shdr - shdr_buf);
				break;
			  case SHF_ALLOC|SHF_WRITE:	/* data area */
				if ( eli->data_ladr != NULL ) {
					err = _ER_REC(TSD_LDE_ERR_3);
					goto err_ret2;
				}
				eli->data_ladr = shdr->sh_addr;
				eli->data_fofs = shdr->sh_offset;
				eli->data_size = shdr->sh_size;
				eli->data_shndx = (UH)(shdr - shdr_buf);
				break;
			  default:
				err = _ER_REC(TSD_LDE_ERR_4);
				goto err_ret2;
			}
			break;

		  case SHT_NOBITS:
			switch ( shdr->sh_flags ) {
			  case SHF_ALLOC|SHF_WRITE:	/* bss area */
				if ( eli->bss_ladr != NULL ) {
					err = _ER_REC(TSD_LDE_ERR_5);
					goto err_ret2;
				}
				eli->bss_ladr = shdr->sh_addr;
				eli->bss_size = shdr->sh_size;
				eli->bss_shndx = (UH)(shdr - shdr_buf);
				break;
			  case SHF_ALLOC:		/* stack area */
				eli->stack_size = shdr->sh_size;
				break;
			  case 0:
				continue; /* Ignore */
			  default:
				err = _ER_REC(TSD_LDE_ERR_6);
				goto err_ret2;
			}
			break;

		  case SHT_REL:
			if ( (shdr->sh_info >= hdr->e_shnum)
			  || (shdr->sh_link >= hdr->e_shnum) ) {
			  	err = _ER_REC(TSD_LDE_ERR_7);
			  	goto err_ret2;
			}

			/* Section to be relocated */
			p = &shdr_buf[shdr->sh_info];
			if ( p->sh_type != SHT_PROGBITS ) {
				continue;
			}

			switch ( p->sh_flags ) {
			  case SHF_ALLOC|SHF_EXECINSTR:	/* text area */
				if ( eli->rel_text_size != 0U ) {
					err = _ER_REC(TSD_LDE_ERR_9);
					goto err_ret2;
				}
				eli->rel_text_fofs = shdr->sh_offset;
				eli->rel_text_size = shdr->sh_size;
				break;
			  case SHF_ALLOC|SHF_WRITE:	/* data area */
				if ( eli->rel_data_size != 0U ) {
					err = _ER_REC(TSD_LDE_ERR_10);
					goto err_ret2;
				}
				eli->rel_data_fofs = shdr->sh_offset;
				eli->rel_data_size = shdr->sh_size;
				break;
			  case 0:
				continue; /* Ignore */
			  default:
				err = _ER_REC(TSD_LDE_ERR_11);
				goto err_ret2;
			}

			if ( (symsect >= 0) && (shdr->sh_link != (UW)symsect) ) {
				err = _ER_REC(TSD_LDE_ERR_12);
				goto err_ret2;
			}
			symsect = (W)shdr->sh_link;
			break;

		  case SHT_MIPS_REGINFO:
	  		if( eli->reginf_size != 0U ) {
				err = _ER_REC(TSD_LDE_ERR_17);
				goto err_ret2;
			}
			eli->reginf_fofs = shdr->sh_offset;
			eli->reginf_size = shdr->sh_size;
		  	break;

		  default:
			continue; /* Ignore */
		}
	}

	/* Check validity */
	if ( eli->text_size == 0U ) {
		err = _ER_REC(TSD_LDE_ERR_13);
		goto err_ret2;
	}
	adr = PageAlignU(eli->text_ladr + eli->text_size);
	if ( eli->data_ladr != adr ) {
		err = _ER_REC(TSD_LDE_ERR_14);
		goto err_ret2;
	}
	adr += eli->data_size;
	if ( eli->bss_ladr < adr ) {
		err = _ER_REC(TSD_LDE_ERR_15);
		goto err_ret2;
	}

	if ( symsect >= 0 ) {
		/* Symbol table for relocation */
		if ( shdr_buf[symsect].sh_type != SHT_SYMTAB ) {
			err = _ER_REC(TSD_LDE_ERR_16);
			goto err_ret2;
		}
		eli->symtbl_fofs = shdr_buf[symsect].sh_offset;
		eli->symtbl_size = shdr_buf[symsect].sh_size;
	}

	Vfree(shdr_buf);

	return E_OK;

err_ret2:
	Vfree(shdr_buf);
err_ret1:
	DEBUG_PRINT(("GetELFLoadInfoShdr err = %d (%d)\n", err, (UH)err));
	return err;
}

/*
 * Obtain loading information from ELF program header
 */
LOCAL BOOL HasDynSeg( Elf32_Ehdr *hdr, POBJ_HDR *pohdr, BzRead *bzr )
{
	Elf32_Phdr	*phdr_buf, *phdr;
	W		n;
	ER		err;

	if ( (hdr->e_phentsize < sizeof(Elf32_Phdr)) || (hdr->e_phnum < 1) ) {
		err = _ER_REC(TSD_LDE_ERR_1);
		goto err_ret1;
	}

	n = hdr->e_phentsize * hdr->e_phnum;
	phdr_buf = Vmalloc((size_t)n);
	if ( phdr_buf == NULL ) {
		err = E_NOMEM;
		goto err_ret1;
	}

	/* Load program header */
	err = ReadProgFile(pohdr, (W)hdr->e_phoff, (VB*)phdr_buf, n, bzr);
	if ( err < E_OK ) {
		goto err_ret2;
	}

	for ( n = (W)hdr->e_phnum, phdr = phdr_buf;
			--n >= 0; phdr = (Elf32_Phdr*)((VB*)phdr + hdr->e_phentsize) ) {

		if ( phdr->p_type == PT_DYNAMIC ) {
			goto found;
		}
	}

	Vfree(phdr_buf);
	return FALSE;
found:
	Vfree(phdr_buf);
	return TRUE;

err_ret2:
	Vfree(phdr_buf);
err_ret1:
	DEBUG_PRINT(("HasDynSeg err = %d (%d)\n", err, (UH)err));
	return FALSE;
}

/*
 * Relocation section check
 */
LOCAL BOOL HasRelSec( Elf32_Ehdr *hdr, POBJ_HDR *pohdr, BzRead *bzr )
{
	Elf32_Shdr	*shdr_buf, *shdr;
	W		n;
	ER		err;

	if ( (hdr->e_shentsize < sizeof(Elf32_Shdr)) || (hdr->e_shnum == 0) ) {
		err = _ER_REC(TSD_LDE_ERR_1);
		goto err_ret1;
	}

	n = hdr->e_shentsize * hdr->e_shnum;
	shdr_buf = Vmalloc((size_t)n);
	if ( shdr_buf == NULL ) {
		err = E_NOMEM;
		goto err_ret1;
	}

	/* Load section header */
	err = ReadProgFile(pohdr, (W)hdr->e_shoff, (VB*)shdr_buf, n, bzr);
	if ( err < E_OK ) {
		goto err_ret2;
	}

	for ( n = (W)hdr->e_shnum, shdr = shdr_buf;
			--n >= 0; shdr = (Elf32_Shdr*)((VB*)shdr + hdr->e_shentsize) ) {

		switch ( shdr->sh_type ) {
		  case SHT_REL:
			goto found;
		  default:
			continue; /* Ignore */
		}
	}