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| author | Jan Beulich <jbeulich@novell.com> | 2006-06-26 13:57:28 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-06-26 10:48:17 -0700 |
| commit | 4552d5dc08b79868829b4be8951b29b07284753f (patch) | |
| tree | 7b25695b4c0e1917fc80e8dd4bc494de36320ccc /kernel/module.c | |
| parent | 2b28592b07223d7fc0691ce3fe57d495dc9cbe3a (diff) | |
| download | linux-stable-4552d5dc08b79868829b4be8951b29b07284753f.tar.gz linux-stable-4552d5dc08b79868829b4be8951b29b07284753f.tar.bz2 linux-stable-4552d5dc08b79868829b4be8951b29b07284753f.zip | |
[PATCH] x86_64: reliable stack trace support
These are the generic bits needed to enable reliable stack traces based
on Dwarf2-like (.eh_frame) unwind information. Subsequent patches will
enable x86-64 and i386 to make use of this.
Thanks to Andi Kleen and Ingo Molnar, who pointed out several possibilities
for improvement.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/module.c')
| -rw-r--r-- | kernel/module.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/kernel/module.c b/kernel/module.c index d75275de1c28..08811e26ac9d 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -40,6 +40,7 @@ #include <linux/string.h> #include <linux/sched.h> #include <linux/mutex.h> +#include <linux/unwind.h> #include <asm/uaccess.h> #include <asm/semaphore.h> #include <asm/cacheflush.h> @@ -1051,6 +1052,8 @@ static void free_module(struct module *mod) remove_sect_attrs(mod); mod_kobject_remove(mod); + unwind_remove_table(mod->unwind_info, 0); + /* Arch-specific cleanup. */ module_arch_cleanup(mod); @@ -1412,7 +1415,7 @@ static struct module *load_module(void __user *umod, unsigned int i, symindex = 0, strindex = 0, setupindex, exindex, exportindex, modindex, obsparmindex, infoindex, gplindex, crcindex, gplcrcindex, versindex, pcpuindex, gplfutureindex, - gplfuturecrcindex; + gplfuturecrcindex, unwindex = 0; struct module *mod; long err = 0; void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */ @@ -1502,6 +1505,9 @@ static struct module *load_module(void __user *umod, versindex = find_sec(hdr, sechdrs, secstrings, "__versions"); infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo"); pcpuindex = find_pcpusec(hdr, sechdrs, secstrings); +#ifdef ARCH_UNWIND_SECTION_NAME + unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME); +#endif /* Don't keep modinfo section */ sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC; @@ -1510,6 +1516,8 @@ static struct module *load_module(void __user *umod, sechdrs[symindex].sh_flags |= SHF_ALLOC; sechdrs[strindex].sh_flags |= SHF_ALLOC; #endif + if (unwindex) + sechdrs[unwindex].sh_flags |= SHF_ALLOC; /* Check module struct version now, before we try to use module. */ if (!check_modstruct_version(sechdrs, versindex, mod)) { @@ -1738,6 +1746,11 @@ static struct module *load_module(void __user *umod, goto arch_cleanup; add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs); + /* Size of section 0 is 0, so this works well if no unwind info. */ + mod->unwind_info = unwind_add_table(mod, + (void *)sechdrs[unwindex].sh_addr, + sechdrs[unwindex].sh_size); + /* Get rid of temporary copy */ vfree(hdr); @@ -1836,6 +1849,7 @@ sys_init_module(void __user *umod, mod->state = MODULE_STATE_LIVE; /* Drop initial reference. */ module_put(mod); + unwind_remove_table(mod->unwind_info, 1); module_free(mod, mod->module_init); mod->module_init = NULL; mod->init_size = 0; |