[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH] x86/boot: Avoid usage of global in reloc.c
All code and dat from this file will go into a text section which we want to not be writeable. Signed-off-by: Frediano Ziglio <frediano.ziglio@xxxxxxxxx> --- xen/arch/x86/boot/reloc.c | 65 +++++++++++++++++++++------------------ 1 file changed, 35 insertions(+), 30 deletions(-) diff --git a/xen/arch/x86/boot/reloc.c b/xen/arch/x86/boot/reloc.c index 201e38d544..c906c2a218 100644 --- a/xen/arch/x86/boot/reloc.c +++ b/xen/arch/x86/boot/reloc.c @@ -72,11 +72,16 @@ struct vesa_mode_info { #define get_mb2_data(tag, type, member) (((const multiboot2_tag_##type##_t *)(tag))->member) #define get_mb2_string(tag, type, member) ((uint32_t)get_mb2_data(tag, type, member)) -static uint32_t alloc; +typedef struct memctx { + /* Simple bump allocator. It starts from the base of the trampoline and + * allocates downwards. + */ + uint32_t ptr; +} memctx; -static uint32_t alloc_mem(uint32_t bytes) +static uint32_t alloc_mem(uint32_t bytes, memctx *ctx) { - return alloc -= ROUNDUP(bytes, 16); + return ctx->ptr -= ROUNDUP(bytes, 16); } static void zero_mem(uint32_t s, uint32_t bytes) @@ -85,11 +90,11 @@ static void zero_mem(uint32_t s, uint32_t bytes) *(char *)s++ = 0; } -static uint32_t copy_mem(uint32_t src, uint32_t bytes) +static uint32_t copy_mem(uint32_t src, uint32_t bytes, memctx *ctx) { uint32_t dst, dst_ret; - dst = alloc_mem(bytes); + dst = alloc_mem(bytes, ctx); dst_ret = dst; while ( bytes-- ) @@ -98,7 +103,7 @@ static uint32_t copy_mem(uint32_t src, uint32_t bytes) return dst_ret; } -static uint32_t copy_string(uint32_t src) +static uint32_t copy_string(uint32_t src, memctx *ctx) { uint32_t p; @@ -108,17 +113,17 @@ static uint32_t copy_string(uint32_t src) for ( p = src; *(char *)p != '\0'; p++ ) continue; - return copy_mem(src, p - src + 1); + return copy_mem(src, p - src + 1, ctx); } -static struct hvm_start_info *pvh_info_reloc(uint32_t in) +static struct hvm_start_info *pvh_info_reloc(uint32_t in, memctx *ctx) { struct hvm_start_info *out; - out = _p(copy_mem(in, sizeof(*out))); + out = _p(copy_mem(in, sizeof(*out), ctx)); if ( out->cmdline_paddr ) - out->cmdline_paddr = copy_string(out->cmdline_paddr); + out->cmdline_paddr = copy_string(out->cmdline_paddr, ctx); if ( out->nr_modules ) { @@ -127,51 +132,51 @@ static struct hvm_start_info *pvh_info_reloc(uint32_t in) out->modlist_paddr = copy_mem(out->modlist_paddr, - out->nr_modules * sizeof(struct hvm_modlist_entry)); + out->nr_modules * sizeof(struct hvm_modlist_entry), ctx); mods = _p(out->modlist_paddr); for ( i = 0; i < out->nr_modules; i++ ) { if ( mods[i].cmdline_paddr ) - mods[i].cmdline_paddr = copy_string(mods[i].cmdline_paddr); + mods[i].cmdline_paddr = copy_string(mods[i].cmdline_paddr, ctx); } } return out; } -static multiboot_info_t *mbi_reloc(uint32_t mbi_in) +static multiboot_info_t *mbi_reloc(uint32_t mbi_in, memctx *ctx) { int i; multiboot_info_t *mbi_out; - mbi_out = _p(copy_mem(mbi_in, sizeof(*mbi_out))); + mbi_out = _p(copy_mem(mbi_in, sizeof(*mbi_out), ctx)); if ( mbi_out->flags & MBI_CMDLINE ) - mbi_out->cmdline = copy_string(mbi_out->cmdline); + mbi_out->cmdline = copy_string(mbi_out->cmdline, ctx); if ( mbi_out->flags & MBI_MODULES ) { module_t *mods; mbi_out->mods_addr = copy_mem(mbi_out->mods_addr, - mbi_out->mods_count * sizeof(module_t)); + mbi_out->mods_count * sizeof(module_t), ctx); mods = _p(mbi_out->mods_addr); for ( i = 0; i < mbi_out->mods_count; i++ ) { if ( mods[i].string ) - mods[i].string = copy_string(mods[i].string); + mods[i].string = copy_string(mods[i].string, ctx); } } if ( mbi_out->flags & MBI_MEMMAP ) - mbi_out->mmap_addr = copy_mem(mbi_out->mmap_addr, mbi_out->mmap_length); + mbi_out->mmap_addr = copy_mem(mbi_out->mmap_addr, mbi_out->mmap_length, ctx); if ( mbi_out->flags & MBI_LOADERNAME ) - mbi_out->boot_loader_name = copy_string(mbi_out->boot_loader_name); + mbi_out->boot_loader_name = copy_string(mbi_out->boot_loader_name, ctx); /* Mask features we don't understand or don't relocate. */ mbi_out->flags &= (MBI_MEMLIMITS | @@ -183,7 +188,7 @@ static multiboot_info_t *mbi_reloc(uint32_t mbi_in) return mbi_out; } -static multiboot_info_t *mbi2_reloc(uint32_t mbi_in, uint32_t video_out) +static multiboot_info_t *mbi2_reloc(uint32_t mbi_in, uint32_t video_out, memctx *ctx) { const multiboot2_fixed_t *mbi_fix = _p(mbi_in); const multiboot2_memory_map_t *mmap_src; @@ -197,7 +202,7 @@ static multiboot_info_t *mbi2_reloc(uint32_t mbi_in, uint32_t video_out) uint32_t ptr; unsigned int i, mod_idx = 0; - ptr = alloc_mem(sizeof(*mbi_out)); + ptr = alloc_mem(sizeof(*mbi_out), ctx); mbi_out = _p(ptr); zero_mem(ptr, sizeof(*mbi_out)); @@ -222,7 +227,7 @@ static multiboot_info_t *mbi2_reloc(uint32_t mbi_in, uint32_t video_out) * __start_xen() may put Xen image placement into it. */ mbi_out->mods_addr = alloc_mem((mbi_out->mods_count + 1) * - sizeof(*mbi_out_mods)); + sizeof(*mbi_out_mods), ctx); mbi_out_mods = _p(mbi_out->mods_addr); } @@ -238,13 +243,13 @@ static multiboot_info_t *mbi2_reloc(uint32_t mbi_in, uint32_t video_out) case MULTIBOOT2_TAG_TYPE_BOOT_LOADER_NAME: mbi_out->flags |= MBI_LOADERNAME; ptr = get_mb2_string(tag, string, string); - mbi_out->boot_loader_name = copy_string(ptr); + mbi_out->boot_loader_name = copy_string(ptr, ctx); break; case MULTIBOOT2_TAG_TYPE_CMDLINE: mbi_out->flags |= MBI_CMDLINE; ptr = get_mb2_string(tag, string, string); - mbi_out->cmdline = copy_string(ptr); + mbi_out->cmdline = copy_string(ptr, ctx); break; case MULTIBOOT2_TAG_TYPE_BASIC_MEMINFO: @@ -263,7 +268,7 @@ static multiboot_info_t *mbi2_reloc(uint32_t mbi_in, uint32_t video_out) mbi_out->mmap_length /= get_mb2_data(tag, mmap, entry_size); mbi_out->mmap_length *= sizeof(*mmap_dst); - mbi_out->mmap_addr = alloc_mem(mbi_out->mmap_length); + mbi_out->mmap_addr = alloc_mem(mbi_out->mmap_length, ctx); mmap_src = get_mb2_data(tag, mmap, entries); mmap_dst = _p(mbi_out->mmap_addr); @@ -290,7 +295,7 @@ static multiboot_info_t *mbi2_reloc(uint32_t mbi_in, uint32_t video_out) mbi_out_mods[mod_idx].mod_start = get_mb2_data(tag, module, mod_start); mbi_out_mods[mod_idx].mod_end = get_mb2_data(tag, module, mod_end); ptr = get_mb2_string(tag, module, cmdline); - mbi_out_mods[mod_idx].string = copy_string(ptr); + mbi_out_mods[mod_idx].string = copy_string(ptr, ctx); mbi_out_mods[mod_idx].reserved = 0; ++mod_idx; break; @@ -356,19 +361,19 @@ static multiboot_info_t *mbi2_reloc(uint32_t mbi_in, uint32_t video_out) void *reloc(uint32_t magic, uint32_t in, uint32_t trampoline, uint32_t video_info) { - alloc = trampoline; + memctx ctx = { trampoline }; switch ( magic ) { case MULTIBOOT_BOOTLOADER_MAGIC: - return mbi_reloc(in); + return mbi_reloc(in, &ctx); case MULTIBOOT2_BOOTLOADER_MAGIC: - return mbi2_reloc(in, video_info); + return mbi2_reloc(in, video_info, &ctx); case XEN_HVM_START_MAGIC_VALUE: if ( IS_ENABLED(CONFIG_PVH_GUEST) ) - return pvh_info_reloc(in); + return pvh_info_reloc(in, &ctx); /* Fallthrough */ default: -- 2.34.1
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