From a3b81113fb6658629f4ebaabf8dd3067cd341020 Mon Sep 17 00:00:00 2001 From: Robin Getz Date: Wed, 6 Feb 2008 01:36:26 -0800 Subject: [PATCH] remove support for un-needed _extratext section When passing a zero address to kallsyms_lookup(), the kernel thought it was a valid kernel address, even if it is not. This is because is_ksym_addr() called is_kernel_extratext() and checked against labels that don't exist on many archs (which default as zero). Since PPC was the only kernel which defines _extra_text, (in 2005), and no longer needs it, this patch removes _extra_text support. For some history (provided by Jon): http://ozlabs.org/pipermail/linuxppc-dev/2005-September/019734.html http://ozlabs.org/pipermail/linuxppc-dev/2005-September/019736.html http://ozlabs.org/pipermail/linuxppc-dev/2005-September/019751.html [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Robin Getz Cc: David Woodhouse Cc: Jon Loeliger Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Sam Ravnborg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/ppc/kernel/vmlinux.lds.S | 5 ----- include/asm-generic/sections.h | 2 -- kernel/kallsyms.c | 11 +---------- scripts/kallsyms.c | 24 ++++++++++-------------- 4 files changed, 11 insertions(+), 31 deletions(-) diff --git a/arch/ppc/kernel/vmlinux.lds.S b/arch/ppc/kernel/vmlinux.lds.S index 52b64fcbdf..8a24bc47eb 100644 --- a/arch/ppc/kernel/vmlinux.lds.S +++ b/arch/ppc/kernel/vmlinux.lds.S @@ -143,11 +143,6 @@ SECTIONS . = ALIGN(4096); __init_end = .; - - . = ALIGN(4096); - _sextratext = .; - _eextratext = .; - __bss_start = .; .bss : { diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h index 962cad7cfb..8feeae1f23 100644 --- a/include/asm-generic/sections.h +++ b/include/asm-generic/sections.h @@ -8,8 +8,6 @@ extern char _data[], _sdata[], _edata[]; extern char __bss_start[], __bss_stop[]; extern char __init_begin[], __init_end[]; extern char _sinittext[], _einittext[]; -extern char _sextratext[] __attribute__((weak)); -extern char _eextratext[] __attribute__((weak)); extern char _end[]; extern char __per_cpu_start[], __per_cpu_end[]; extern char __kprobes_text_start[], __kprobes_text_end[]; diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 7dadc71ce5..f091d13def 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -53,14 +53,6 @@ static inline int is_kernel_inittext(unsigned long addr) return 0; } -static inline int is_kernel_extratext(unsigned long addr) -{ - if (addr >= (unsigned long)_sextratext - && addr <= (unsigned long)_eextratext) - return 1; - return 0; -} - static inline int is_kernel_text(unsigned long addr) { if (addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) @@ -80,8 +72,7 @@ static int is_ksym_addr(unsigned long addr) if (all_var) return is_kernel(addr); - return is_kernel_text(addr) || is_kernel_inittext(addr) || - is_kernel_extratext(addr); + return is_kernel_text(addr) || is_kernel_inittext(addr); } /* expand a compressed symbol data into the resulting uncompressed string, diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c index 1f11d84853..8fb87003d5 100644 --- a/scripts/kallsyms.c +++ b/scripts/kallsyms.c @@ -41,7 +41,7 @@ struct sym_entry { static struct sym_entry *table; static unsigned int table_size, table_cnt; -static unsigned long long _text, _stext, _etext, _sinittext, _einittext, _sextratext, _eextratext; +static unsigned long long _text, _stext, _etext, _sinittext, _einittext; static int all_symbols = 0; static char symbol_prefix_char = '\0'; @@ -99,10 +99,6 @@ static int read_symbol(FILE *in, struct sym_entry *s) _sinittext = s->addr; else if (strcmp(sym, "_einittext") == 0) _einittext = s->addr; - else if (strcmp(sym, "_sextratext") == 0) - _sextratext = s->addr; - else if (strcmp(sym, "_eextratext") == 0) - _eextratext = s->addr; else if (toupper(stype) == 'A') { /* Keep these useful absolute symbols */ @@ -165,18 +161,18 @@ static int symbol_valid(struct sym_entry *s) * and inittext sections are discarded */ if (!all_symbols) { if ((s->addr < _stext || s->addr > _etext) - && (s->addr < _sinittext || s->addr > _einittext) - && (s->addr < _sextratext || s->addr > _eextratext)) + && (s->addr < _sinittext || s->addr > _einittext)) return 0; /* Corner case. Discard any symbols with the same value as - * _etext _einittext or _eextratext; they can move between pass - * 1 and 2 when the kallsyms data are added. If these symbols - * move then they may get dropped in pass 2, which breaks the - * kallsyms rules. + * _etext _einittext; they can move between pass 1 and 2 when + * the kallsyms data are added. If these symbols move then + * they may get dropped in pass 2, which breaks the kallsyms + * rules. */ - if ((s->addr == _etext && strcmp((char*)s->sym + offset, "_etext")) || - (s->addr == _einittext && strcmp((char*)s->sym + offset, "_einittext")) || - (s->addr == _eextratext && strcmp((char*)s->sym + offset, "_eextratext"))) + if ((s->addr == _etext && + strcmp((char *)s->sym + offset, "_etext")) || + (s->addr == _einittext && + strcmp((char *)s->sym + offset, "_einittext"))) return 0; } -- 2.39.5