On Fri, 26 Oct 2007 15:43:56 -0400 Robin Getz <[EMAIL PROTECTED]> wrote:
> From: Robin Getz <[EMAIL PROTECTED]> > > 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. I hit numerous rejects here. I am not sure which kernel you patched but I suspect it was not an up-to-date one. > --- kernel/kallsyms.c (revision 3780) > +++ kernel/kallsyms.c (working copy) Please prepare patches in `patch -p1' form. This should have been --- foo/kernel/kallsyms.c (revision 3780) +++ bar/kernel/kallsyms.c (working copy) > */ > 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"))) > + (s->addr == _einittext && strcmp((char*)s->sym + offset, > "_einittext"))) > return 0; > } I don't understand why this hunk is changing _einittext handling, and I suspect this was a mistake, so I left that bit out. I ended up with this: From: Robin Getz <[EMAIL PROTECTED]> 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 Signed-off-by: Robin Getz <[EMAIL PROTECTED]> Cc: David Woodhouse <[EMAIL PROTECTED]> Cc: Jon Loeliger <[EMAIL PROTECTED]> Cc: Paul Mackerras <[EMAIL PROTECTED]> Cc: Benjamin Herrenschmidt <[EMAIL PROTECTED]> Cc: Sam Ravnborg <[EMAIL PROTECTED]> Signed-off-by: Andrew Morton <[EMAIL PROTECTED]> --- 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 -puN arch/ppc/kernel/vmlinux.lds.S~remove-support-for-un-needed-_extratext-section arch/ppc/kernel/vmlinux.lds.S --- a/arch/ppc/kernel/vmlinux.lds.S~remove-support-for-un-needed-_extratext-section +++ a/arch/ppc/kernel/vmlinux.lds.S @@ -143,11 +143,6 @@ SECTIONS . = ALIGN(4096); __init_end = .; - - . = ALIGN(4096); - _sextratext = .; - _eextratext = .; - __bss_start = .; .bss : { diff -puN include/asm-generic/sections.h~remove-support-for-un-needed-_extratext-section include/asm-generic/sections.h --- a/include/asm-generic/sections.h~remove-support-for-un-needed-_extratext-section +++ a/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 -puN kernel/kallsyms.c~remove-support-for-un-needed-_extratext-section kernel/kallsyms.c --- a/kernel/kallsyms.c~remove-support-for-un-needed-_extratext-section +++ a/kernel/kallsyms.c @@ -48,14 +48,6 @@ static inline int is_kernel_inittext(uns 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) @@ -75,8 +67,7 @@ static int is_ksym_addr(unsigned long ad 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 -puN scripts/kallsyms.c~remove-support-for-un-needed-_extratext-section scripts/kallsyms.c --- a/scripts/kallsyms.c~remove-support-for-un-needed-_extratext-section +++ a/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 _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 * 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; } _ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
