From 68cd2e93537bee644f0595cb0b734fe53cfa0637 Mon Sep 17 00:00:00 2001
From: Vladimir 'phcoder' Serbinenko <phcoder@gmail.com>
Date: Thu, 7 Mar 2013 08:17:24 +0100
Subject: [PATCH 195/364] Lift up core size limits on some platforms.
Fix potential memory corruption with big core on small memory systems.
Document remaining limits.
---
ChangeLog | 6 ++++
docs/grub.texi | 38 +++++++++++++++++++++++++
grub-core/kern/i386/coreboot/init.c | 38 ++++++++++++++-----------
grub-core/kern/i386/pc/init.c | 12 +++++++-
grub-core/kern/main.c | 56 ++++++++++++++++++++++++++++++++-----
grub-core/kern/mm.c | 21 ++++++++++++++
include/grub/kernel.h | 25 +++++++++++++++++
include/grub/offsets.h | 1 +
util/grub-mkimage.c | 47 +++++++++++++++++++++++++------
9 files changed, 211 insertions(+), 33 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index f1ab52a..96527dd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2013-03-07 Vladimir Serbinenko <phcoder@gmail.com>
+
+ Lift up core size limits on some platforms. Fix potential memory
+ corruption with big core on small memory systems. Document remaining
+ limits.
+
2013-03-05 Vladimir Serbinenko <phcoder@gmail.com>
* grub-core/term/terminfo.c (grub_terminfo_cls): Issue an explicit
diff --git a/docs/grub.texi b/docs/grub.texi
index 9941b47..0b66827 100644
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -89,6 +89,7 @@ This edition documents version @value{VERSION}.
* Serial terminal:: Using GRUB via a serial line
* Vendor power-on keys:: Changing GRUB behaviour on vendor power-on keys
* Images:: GRUB image files
+* Core image size limitation:: GRUB image files size limitations
* Filesystem:: Filesystem syntax and semantics
* Interface:: The menu and the command-line
* Environment:: GRUB environment variables
@@ -2390,6 +2391,43 @@ In GRUB 2, images for PXE network booting are now constructed using
contains the @samp{pxe} and @samp{pxecmd} modules. @xref{Network}.
@end table
+@node Core image size limitation
+@chapter Core image size limitation
+
+Heavily limited platforms:
+@itemize
+@item i386-pc (normal and PXE): the core image size (compressed) is limited by 458240 bytes.
+ kernel.img (.text + .data + .bss, uncompressed) is limited by 392704 bytes.
+ module size (uncompressed) + kernel.img (.text + .data, uncompressed) is limited by the size of contiguous chunk at 1M address.
+@item sparc64-ieee1275: kernel.img (.text + .data + .bss) + modules + 256K (stack) + 2M (heap) is limited by space available at 0x4400. On most platforms it's just 3 or 4M since ieee1275 maps only so much.
+@item i386-ieee1275: kernel.img (.text + .data + .bss) + modules is limited by memory available at 0x10000, at most 596K
+@end itemize
+
+Lightly limited platforms:
+
+@itemize
+@item i386-qemu: kernel.img (.text + .data + .bss) is limited by 392704 bytes.
+ (core.img would be limited by ROM size but it's unlimited on qemu
+@item All EFI platforms: limited by contiguous RAM size and possibly firmware bugs
+@item Coreboot and multiboot. kernel.img (.text + .data + .bss) is limited by 392704 bytes.
+ module size is limited by the size of contiguous chunk at 1M address.
+@item mipsel-loongson (ELF), mips(el)-qemu_mips (ELF): if uncompressed:
+ kernel.img (.text + .data) + modules is limited by the space from 80200000 forward
+ if compressed:
+ kernel.img (.text + .data, uncompressed) + modules (uncompressed)
+ + (modules + kernel.img (.text + .data)) (compressed)
+ + decompressor is limited by the space from 80200000 forward
+@item mipsel-loongson (Flash), mips(el)-qemu_mips (Flash): kernel.img (.text + .data) + modules is limited by the space from 80200000 forward
+ core.img (final) is limited by flash size (512K on yeeloong and fulooong)
+@item mips-arc: if uncompressed:
+ kernel.img (.text + .data) is limited by the space from 8bd00000 forward
+ modules + dummy decompressor is limited by the space from 8bd00000 backward
+ if compressed:
+ kernel.img (.text + .data, uncompressed) is limited by the space from 8bd00000 forward
+ modules (uncompressed) + (modules + kernel.img (.text + .data)) (compressed, aligned to 1M)
+ + 1M (decompressor + scratch space) is limited by the space from 8bd00000 backward
+@item powerpc-ieee1275: kernel.img (.text + .data + .bss) + modules is limited by space available at 0x200000
+@end itemize
@node Filesystem
@chapter Filesystem syntax and semantics
diff --git a/grub-core/kern/i386/coreboot/init.c b/grub-core/kern/i386/coreboot/init.c
index 48fd1a6..bfc8f3f 100644
--- a/grub-core/kern/i386/coreboot/init.c
+++ b/grub-core/kern/i386/coreboot/init.c
@@ -54,7 +54,8 @@ grub_exit (void)
#ifdef GRUB_MACHINE_QEMU
grub_addr_t grub_modbase;
#else
-grub_addr_t grub_modbase = ALIGN_UP((grub_addr_t) _end, GRUB_KERNEL_MACHINE_MOD_ALIGN);
+grub_addr_t grub_modbase = GRUB_KERNEL_I386_COREBOOT_MODULES_ADDR;
+static grub_uint64_t modend;
#endif
/* Helper for grub_machine_init. */
@@ -62,30 +63,32 @@ static int
heap_init (grub_uint64_t addr, grub_uint64_t size, grub_memory_type_t type,
void *data __attribute__ ((unused)))
{
+ grub_uint64_t begin = addr, end = addr + size;
+
#if GRUB_CPU_SIZEOF_VOID_P == 4
/* Restrict ourselves to 32-bit memory space. */
- if (addr > GRUB_ULONG_MAX)
+ if (begin > GRUB_ULONG_MAX)
return 0;
- if (addr + size > GRUB_ULONG_MAX)
- size = GRUB_ULONG_MAX - addr;
+ if (end > GRUB_ULONG_MAX)
+ end = GRUB_ULONG_MAX;
#endif
if (type != GRUB_MEMORY_AVAILABLE)
return 0;
/* Avoid the lower memory. */
- if (addr < GRUB_MEMORY_MACHINE_LOWER_SIZE)
- {
- if (addr + size <= GRUB_MEMORY_MACHINE_LOWER_SIZE)
- return 0;
- else
- {
- size -= GRUB_MEMORY_MACHINE_LOWER_SIZE - addr;
- addr = GRUB_MEMORY_MACHINE_LOWER_SIZE;
- }
- }
-
- grub_mm_init_region ((void *) (grub_addr_t) addr, (grub_size_t) size);
+ if (begin < GRUB_MEMORY_MACHINE_LOWER_SIZE)
+ begin = GRUB_MEMORY_MACHINE_LOWER_SIZE;
+
+#ifndef GRUB_MACHINE_QEMU
+ if (modend && begin < modend)
+ begin = modend;
+#endif
+
+ if (end <= begin)
+ return 0;
+
+ grub_mm_init_region ((void *) (grub_addr_t) begin, (grub_size_t) (end - begin));
return 0;
}
@@ -98,6 +101,9 @@ grub_machine_init (void)
grub_qemu_init_cirrus ();
#endif
+#ifndef GRUB_MACHINE_QEMU
+ modend = grub_modules_get_end ();
+#endif
/* Initialize the console as early as possible. */
grub_vga_text_init ();
diff --git a/grub-core/kern/i386/pc/init.c b/grub-core/kern/i386/pc/init.c
index 7d8b12c..730e04a 100644
--- a/grub-core/kern/i386/pc/init.c
+++ b/grub-core/kern/i386/pc/init.c
@@ -191,6 +191,7 @@ grub_machine_init (void)
#if 0
int grub_lower_mem;
#endif
+ grub_addr_t modend;
grub_modbase = GRUB_MEMORY_MACHINE_DECOMPRESSION_ADDR + (_edata - _start);
@@ -222,8 +223,17 @@ grub_machine_init (void)
compact_mem_regions ();
+ modend = grub_modules_get_end ();
for (i = 0; i < num_regions; i++)
- grub_mm_init_region ((void *) mem_regions[i].addr, mem_regions[i].size);
+ {
+ grub_addr_t beg = mem_regions[i].addr;
+ grub_addr_t fin = mem_regions[i].addr + mem_regions[i].size;
+ if (modend && beg < modend)
+ beg = modend;
+ if (beg >= fin)
+ continue;
+ grub_mm_init_region ((void *) beg, fin - beg);
+ }
grub_tsc_init ();
}
diff --git a/grub-core/kern/main.c b/grub-core/kern/main.c
index c43ac6b..e1a2001 100644
--- a/grub-core/kern/main.c
+++ b/grub-core/kern/main.c
@@ -30,8 +30,10 @@
#include <grub/reader.h>
#include <grub/parser.h>
-/* This is actualy platform-independant but used only on loongson and sparc. */
-#if defined (GRUB_MACHINE_MIPS_LOONGSON) || defined (GRUB_MACHINE_MIPS_QEMU_MIPS) || defined (GRUB_MACHINE_SPARC64)
+#ifdef GRUB_MACHINE_PCBIOS
+#include <grub/machine/memory.h>
+#endif
+
grub_addr_t
grub_modules_get_end (void)
{
@@ -45,7 +47,6 @@ grub_modules_get_end (void)
return grub_modbase + modinfo->size;
}
-#endif
/* Load all modules in core. */
static void
@@ -67,6 +68,8 @@ grub_load_modules (void)
}
}
+static char *load_config;
+
static void
grub_load_config (void)
{
@@ -76,9 +79,17 @@ grub_load_config (void)
/* Not an embedded config, skip. */
if (header->type != OBJ_TYPE_CONFIG)
continue;
-
- grub_parser_execute ((char *) header +
- sizeof (struct grub_module_header));
+
+ load_config = grub_malloc (header->size - sizeof (struct grub_module_header) + 1);
+ if (!load_config)
+ {
+ grub_print_error ();
+ break;
+ }
+ grub_memcpy (load_config, (char *) header +
+ sizeof (struct grub_module_header),
+ header->size - sizeof (struct grub_module_header));
+ load_config[header->size - sizeof (struct grub_module_header)] = 0;
break;
}
}
@@ -212,6 +223,30 @@ grub_load_normal_mode (void)
grub_command_execute ("normal", 0, 0);
}
+static void
+reclaim_module_space (void)
+{
+ grub_addr_t modstart, modend;
+
+ if (!grub_modbase)
+ return;
+
+#ifdef GRUB_MACHINE_PCBIOS
+ modstart = GRUB_MEMORY_MACHINE_DECOMPRESSION_ADDR;
+#else
+ modstart = grub_modbase;
+#endif
+ modend = grub_modules_get_end ();
+ grub_modbase = 0;
+
+#if GRUB_KERNEL_PRELOAD_SPACE_REUSABLE
+ grub_mm_init_region ((void *) modstart, modend - modstart);
+#else
+ (void) modstart;
+ (void) modend;
+#endif
+}
+
/* The main routine. */
void __attribute__ ((noreturn))
grub_main (void)
@@ -224,6 +259,8 @@ grub_main (void)
grub_printf ("Welcome to GRUB!\n\n");
grub_setcolorstate (GRUB_TERM_COLOR_STANDARD);
+ grub_load_config ();
+
/* Load pre-loaded modules and free the space. */
grub_register_exported_symbols ();
#ifdef GRUB_LINKER_HAVE_INIT
@@ -237,9 +274,14 @@ grub_main (void)
grub_env_export ("root");
grub_env_export ("prefix");
+ /* Reclaim space used for modules. */
+ reclaim_module_space ();
+
grub_register_core_commands ();
- grub_load_config ();
+ if (load_config)
+ grub_parser_execute (load_config);
+
grub_load_normal_mode ();
grub_rescue_run ();
}
diff --git a/grub-core/kern/mm.c b/grub-core/kern/mm.c
index 9f08e05..d869091 100644
--- a/grub-core/kern/mm.c
+++ b/grub-core/kern/mm.c
@@ -117,6 +117,27 @@ grub_mm_init_region (void *addr, grub_size_t size)
grub_printf ("Using memory for heap: start=%p, end=%p\n", addr, addr + (unsigned int) size);
#endif
+ for (p = &grub_mm_base, q = *p; q; p = &(q->next), q = *p)
+ if ((grub_uint8_t *) addr + size + q->pre_size == (grub_uint8_t *) q)
+ {
+ r = (grub_mm_region_t) ALIGN_UP ((grub_addr_t) addr, GRUB_MM_ALIGN);
+ *r = *q;
+ r->pre_size += size;
+
+ if (r->pre_size >> GRUB_MM_ALIGN_LOG2)
+ {
+ h = (grub_mm_header_t) (r + 1);
+ h->size = (r->pre_size >> GRUB_MM_ALIGN_LOG2);
+ h->magic = GRUB_MM_ALLOC_MAGIC;
+ r->size += h->size << GRUB_MM_ALIGN_LOG2;
+ r->pre_size &= (GRUB_MM_ALIGN - 1);
+ *p = r;
+ grub_free (h + 1);
+ }
+ *p = r;
+ return;
+ }
+
/* Allocate a region from the head. */
r = (grub_mm_region_t) ALIGN_UP ((grub_addr_t) addr, GRUB_MM_ALIGN);
size -= (char *) r - (char *) addr + sizeof (*r);
diff --git a/include/grub/kernel.h b/include/grub/kernel.h
index 23e4f02..73ea416 100644
--- a/include/grub/kernel.h
+++ b/include/grub/kernel.h
@@ -64,6 +64,29 @@ struct grub_module_info64
grub_uint64_t size;
};
+#ifndef GRUB_UTIL
+/* Space isn't reusable on some platforms. */
+/* On Qemu the preload space is readonly. */
+/* On emu there is no preload space. */
+/* On ieee1275 our code assumes that heap is p=v which isn't guaranteed for module space. */
+#if defined (GRUB_MACHINE_QEMU) || defined (GRUB_MACHINE_EMU) \
+ || defined (GRUB_MACHINE_EFI) \
+ || (defined (GRUB_MACHINE_IEEE1275) && !defined (__sparc__))
+#define GRUB_KERNEL_PRELOAD_SPACE_REUSABLE 0
+#endif
+
+#if defined (GRUB_MACHINE_PCBIOS) || defined (GRUB_MACHINE_COREBOOT) \
+ || defined (GRUB_MACHINE_MULTIBOOT) || defined (GRUB_MACHINE_MIPS_QEMU_MIPS) \
+ || defined (GRUB_MACHINE_MIPS_LOONGSON) || defined (GRUB_MACHINE_ARC) \
+ || defined (__sparc__)
+/* FIXME: stack is between 2 heap regions. Move it. */
+#define GRUB_KERNEL_PRELOAD_SPACE_REUSABLE 1
+#endif
+
+#ifndef GRUB_KERNEL_PRELOAD_SPACE_REUSABLE
+#error "Please check if preload space is reusable on this platform!"
+#endif
+
#if GRUB_TARGET_SIZEOF_VOID_P == 8
#define grub_module_info grub_module_info64
#else
@@ -82,6 +105,8 @@ extern grub_addr_t EXPORT_VAR (grub_modbase);
grub_addr_t grub_modules_get_end (void);
+#endif
+
/* The start point of the C code. */
void grub_main (void) __attribute__ ((noreturn));
diff --git a/include/grub/offsets.h b/include/grub/offsets.h
index d55e308..bce755d 100644
--- a/include/grub/offsets.h
+++ b/include/grub/offsets.h
@@ -91,6 +91,7 @@
#define GRUB_KERNEL_MIPS_ARC_TOTAL_MODULE_SIZE 0x08
#define GRUB_KERNEL_I386_COREBOOT_LINK_ADDR 0x8200
+#define GRUB_KERNEL_I386_COREBOOT_MODULES_ADDR 0x100000
#define GRUB_KERNEL_I386_IEEE1275_LINK_ADDR 0x10000
diff --git a/util/grub-mkimage.c b/util/grub-mkimage.c
index 29bda17..845abed 100644
--- a/util/grub-mkimage.c
+++ b/util/grub-mkimage.c
@@ -995,16 +995,42 @@ generate_image (const char *dir, const char *prefix,
{
case IMAGE_I386_PC:
case IMAGE_I386_PC_PXE:
- {
- unsigned num;
- char *boot_path, *boot_img;
- size_t boot_size;
-
if (GRUB_KERNEL_I386_PC_LINK_ADDR + core_size > 0x78000
- || (core_size > (0xffff << GRUB_DISK_SECTOR_BITS)))
+ || (core_size > (0xffff << GRUB_DISK_SECTOR_BITS))
+ || (kernel_size + bss_size + GRUB_KERNEL_I386_PC_LINK_ADDR > 0x68000))
grub_util_error (_("core image is too big (0x%x > 0x%x)"),
GRUB_KERNEL_I386_PC_LINK_ADDR + core_size,
0x78000);
+ /* fallthrough */
+ case IMAGE_COREBOOT:
+ case IMAGE_QEMU:
+ if (kernel_size + bss_size + GRUB_KERNEL_I386_PC_LINK_ADDR > 0x68000)
+ grub_util_error (_("kernel image is too big (0x%x > 0x%x)"),
+ kernel_size + bss_size + GRUB_KERNEL_I386_PC_LINK_ADDR,
+ 0x68000);
+ break;
+ case IMAGE_LOONGSON_ELF:
+ case IMAGE_YEELOONG_FLASH:
+ case IMAGE_FULOONG2F_FLASH:
+ case IMAGE_EFI:
+ case IMAGE_MIPS_ARC:
+ case IMAGE_QEMU_MIPS_FLASH:
+ break;
+ case IMAGE_SPARC64_AOUT:
+ case IMAGE_SPARC64_RAW:
+ case IMAGE_I386_IEEE1275:
+ case IMAGE_PPC:
+ break;
+ }
+
+ switch (image_target->id)
+ {
+ case IMAGE_I386_PC:
+ case IMAGE_I386_PC_PXE:
+ {
+ unsigned num;
+ char *boot_path, *boot_img;
+ size_t boot_size;
num = ((core_size + GRUB_DISK_SECTOR_SIZE - 1) >> GRUB_DISK_SECTOR_BITS);
if (image_target->id == IMAGE_I386_PC_PXE)
@@ -1615,9 +1641,12 @@ generate_image (const char *dir, const char *prefix,
phdr->p_filesz = phdr->p_memsz
= grub_host_to_target32 (core_size - kernel_size);
- target_addr_mods = ALIGN_UP (target_addr + kernel_size + bss_size
- + image_target->mod_gap,
- image_target->mod_align);
+ if (image_target->id == IMAGE_COREBOOT)
+ target_addr_mods = GRUB_KERNEL_I386_COREBOOT_MODULES_ADDR;
+ else
+ target_addr_mods = ALIGN_UP (target_addr + kernel_size + bss_size
+ + image_target->mod_gap,
+ image_target->mod_align);
phdr->p_vaddr = grub_host_to_target32 (target_addr_mods);
phdr->p_paddr = grub_host_to_target32 (target_addr_mods);
phdr->p_align = grub_host_to_target32 (image_target->link_align);
--
1.8.1.4