| Message ID | 1316170684-1914-1-git-send-email-avik.sil@linaro.org |
|---|---|
| State | New |
| Headers | show |
* Avik Sil (avik.sil@linaro.org) wrote: > This patch fixes the undefined instruction oops due to execution > of thumb-2 code in ARM mode. The zero bit in the symbol address > returned by kallsyms_lookup_name is not set, leading to switching > to ARM mode that generates oops while executing thumb-2 code. For > detailed discussion, see [1]. > [1] http://lists.casi.polymtl.ca/pipermail/ltt-dev/2011-September/005176.html Hi Avik, Instead of modifying all those wrappers individually, can you create a wrapper/kallsyms.h and create a wrapper for kallsyms_lookup_name ? This way, the ifdef for the ARM special-case would only appear once. Thanks! Mathieu > > Signed-off-by: Avik Sil <avik.sil@linaro.org> > --- > lttng-context-prio.c | 11 ++++++++++- > wrapper/ftrace.h | 28 ++++++++++++++++++++++------ > wrapper/splice.c | 14 ++++++++++++-- > wrapper/vmalloc.h | 14 +++++++++++--- > 4 files changed, 55 insertions(+), 12 deletions(-) > > diff --git a/lttng-context-prio.c b/lttng-context-prio.c > index ad1c42f..5e8c0d2 100644 > --- a/lttng-context-prio.c > +++ b/lttng-context-prio.c > @@ -20,7 +20,16 @@ int (*wrapper_task_prio_sym)(struct task_struct *t); > > int wrapper_task_prio_init(void) > { > - wrapper_task_prio_sym = (void *) kallsyms_lookup_name("task_prio"); > + unsigned long addr; > + > + addr = kallsyms_lookup_name("task_prio"); > +#ifdef CONFIG_ARM > +#ifdef CONFIG_THUMB2_KERNEL > + if (addr) > + addr |= 1; /* set bit 0 in address for thumb mode */ > +#endif > +#endif > + wrapper_task_prio_sym = (void *) addr; > if (!wrapper_task_prio_sym) { > printk(KERN_WARNING "LTTng: task_prio symbol lookup failed.\n"); > return -EINVAL; > diff --git a/wrapper/ftrace.h b/wrapper/ftrace.h > index 9c18cc5..d79aa5e 100644 > --- a/wrapper/ftrace.h > +++ b/wrapper/ftrace.h > @@ -21,10 +21,18 @@ static inline > int wrapper_register_ftrace_function_probe(char *glob, > struct ftrace_probe_ops *ops, void *data) > { > - int (*register_ftrace_function_probe_sym)(char *glob, > - struct ftrace_probe_ops *ops, void *data); > + unsigned long addr; > + int (*register_ftrace_function_probe_sym)(char *glob, > + struct ftrace_probe_ops *ops, void *data); > > - register_ftrace_function_probe_sym = (void *) kallsyms_lookup_name("register_ftrace_function_probe"); > + addr = kallsyms_lookup_name("register_ftrace_function_probe"); > +#ifdef CONFIG_ARM > +#ifdef CONFIG_THUMB2_KERNEL > + if (addr) > + addr |= 1; /* set bit 0 in address for thumb mode */ > +#endif > +#endif > + register_ftrace_function_probe_sym = (void *) addr; > if (register_ftrace_function_probe_sym) { > return register_ftrace_function_probe_sym(glob, ops, data); > } else { > @@ -37,10 +45,18 @@ static inline > void wrapper_unregister_ftrace_function_probe(char *glob, > struct ftrace_probe_ops *ops, void *data) > { > - void (*unregister_ftrace_function_probe_sym)(char *glob, > - struct ftrace_probe_ops *ops, void *data); > + unsigned long addr; > + void (*unregister_ftrace_function_probe_sym)(char *glob, > + struct ftrace_probe_ops *ops, void *data); > > - unregister_ftrace_function_probe_sym = (void *) kallsyms_lookup_name("unregister_ftrace_function_probe"); > + addr = kallsyms_lookup_name("unregister_ftrace_function_probe"); > +#ifdef CONFIG_ARM > +#ifdef CONFIG_THUMB2_KERNEL > + if (addr) > + addr |= 1; /* set bit 0 in address for thumb mode */ > +#endif > +#endif > + unregister_ftrace_function_probe_sym = (void *) addr; > if (unregister_ftrace_function_probe_sym) { > unregister_ftrace_function_probe_sym(glob, ops, data); > } else { > diff --git a/wrapper/splice.c b/wrapper/splice.c > index edc499c..c2c275b 100644 > --- a/wrapper/splice.c > +++ b/wrapper/splice.c > @@ -21,8 +21,18 @@ ssize_t (*splice_to_pipe_sym)(struct pipe_inode_info *pipe, > ssize_t wrapper_splice_to_pipe(struct pipe_inode_info *pipe, > struct splice_pipe_desc *spd) > { > - if (!splice_to_pipe_sym) > - splice_to_pipe_sym = (void *) kallsyms_lookup_name("splice_to_pipe"); > + unsigned long addr; > + > + if (!splice_to_pipe_sym) { > + addr = kallsyms_lookup_name("splice_to_pipe"); > +#ifdef CONFIG_ARM > +#ifdef CONFIG_THUMB2_KERNEL > + if (addr) > + addr |= 1; /* set bit 0 in address for thumb mode */ > +#endif > +#endif > + splice_to_pipe_sym = (void *) addr; > + } > if (splice_to_pipe_sym) { > return splice_to_pipe_sym(pipe, spd); > } else { > diff --git a/wrapper/vmalloc.h b/wrapper/vmalloc.h > index 7d87855..d512c89 100644 > --- a/wrapper/vmalloc.h > +++ b/wrapper/vmalloc.h > @@ -18,9 +18,17 @@ > static inline > void wrapper_vmalloc_sync_all(void) > { > - void (*vmalloc_sync_all_sym)(void); > - > - vmalloc_sync_all_sym = (void *) kallsyms_lookup_name("vmalloc_sync_all"); > + unsigned long addr; > + void (*vmalloc_sync_all_sym)(void); > + > + addr = kallsyms_lookup_name("vmalloc_sync_all"); > +#ifdef CONFIG_ARM > +#ifdef CONFIG_THUMB2_KERNEL > + if (addr) > + addr |= 1; /* set bit 0 in address for thumb mode */ > +#endif > +#endif > + vmalloc_sync_all_sym = (void *) addr; > if (vmalloc_sync_all_sym) { > vmalloc_sync_all_sym(); > } else { > -- > 1.7.0.4 > > > _______________________________________________ > ltt-dev mailing list > ltt-dev@lists.casi.polymtl.ca > http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev >
diff --git a/lttng-context-prio.c b/lttng-context-prio.c index ad1c42f..5e8c0d2 100644 --- a/lttng-context-prio.c +++ b/lttng-context-prio.c @@ -20,7 +20,16 @@ int (*wrapper_task_prio_sym)(struct task_struct *t); int wrapper_task_prio_init(void) { - wrapper_task_prio_sym = (void *) kallsyms_lookup_name("task_prio"); + unsigned long addr; + + addr = kallsyms_lookup_name("task_prio"); +#ifdef CONFIG_ARM +#ifdef CONFIG_THUMB2_KERNEL + if (addr) + addr |= 1; /* set bit 0 in address for thumb mode */ +#endif +#endif + wrapper_task_prio_sym = (void *) addr; if (!wrapper_task_prio_sym) { printk(KERN_WARNING "LTTng: task_prio symbol lookup failed.\n"); return -EINVAL; diff --git a/wrapper/ftrace.h b/wrapper/ftrace.h index 9c18cc5..d79aa5e 100644 --- a/wrapper/ftrace.h +++ b/wrapper/ftrace.h @@ -21,10 +21,18 @@ static inline int wrapper_register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, void *data) { - int (*register_ftrace_function_probe_sym)(char *glob, - struct ftrace_probe_ops *ops, void *data); + unsigned long addr; + int (*register_ftrace_function_probe_sym)(char *glob, + struct ftrace_probe_ops *ops, void *data); - register_ftrace_function_probe_sym = (void *) kallsyms_lookup_name("register_ftrace_function_probe"); + addr = kallsyms_lookup_name("register_ftrace_function_probe"); +#ifdef CONFIG_ARM +#ifdef CONFIG_THUMB2_KERNEL + if (addr) + addr |= 1; /* set bit 0 in address for thumb mode */ +#endif +#endif + register_ftrace_function_probe_sym = (void *) addr; if (register_ftrace_function_probe_sym) { return register_ftrace_function_probe_sym(glob, ops, data); } else { @@ -37,10 +45,18 @@ static inline void wrapper_unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, void *data) { - void (*unregister_ftrace_function_probe_sym)(char *glob, - struct ftrace_probe_ops *ops, void *data); + unsigned long addr; + void (*unregister_ftrace_function_probe_sym)(char *glob, + struct ftrace_probe_ops *ops, void *data); - unregister_ftrace_function_probe_sym = (void *) kallsyms_lookup_name("unregister_ftrace_function_probe"); + addr = kallsyms_lookup_name("unregister_ftrace_function_probe"); +#ifdef CONFIG_ARM +#ifdef CONFIG_THUMB2_KERNEL + if (addr) + addr |= 1; /* set bit 0 in address for thumb mode */ +#endif +#endif + unregister_ftrace_function_probe_sym = (void *) addr; if (unregister_ftrace_function_probe_sym) { unregister_ftrace_function_probe_sym(glob, ops, data); } else { diff --git a/wrapper/splice.c b/wrapper/splice.c index edc499c..c2c275b 100644 --- a/wrapper/splice.c +++ b/wrapper/splice.c @@ -21,8 +21,18 @@ ssize_t (*splice_to_pipe_sym)(struct pipe_inode_info *pipe, ssize_t wrapper_splice_to_pipe(struct pipe_inode_info *pipe, struct splice_pipe_desc *spd) { - if (!splice_to_pipe_sym) - splice_to_pipe_sym = (void *) kallsyms_lookup_name("splice_to_pipe"); + unsigned long addr; + + if (!splice_to_pipe_sym) { + addr = kallsyms_lookup_name("splice_to_pipe"); +#ifdef CONFIG_ARM +#ifdef CONFIG_THUMB2_KERNEL + if (addr) + addr |= 1; /* set bit 0 in address for thumb mode */ +#endif +#endif + splice_to_pipe_sym = (void *) addr; + } if (splice_to_pipe_sym) { return splice_to_pipe_sym(pipe, spd); } else { diff --git a/wrapper/vmalloc.h b/wrapper/vmalloc.h index 7d87855..d512c89 100644 --- a/wrapper/vmalloc.h +++ b/wrapper/vmalloc.h @@ -18,9 +18,17 @@ static inline void wrapper_vmalloc_sync_all(void) { - void (*vmalloc_sync_all_sym)(void); - - vmalloc_sync_all_sym = (void *) kallsyms_lookup_name("vmalloc_sync_all"); + unsigned long addr; + void (*vmalloc_sync_all_sym)(void); + + addr = kallsyms_lookup_name("vmalloc_sync_all"); +#ifdef CONFIG_ARM +#ifdef CONFIG_THUMB2_KERNEL + if (addr) + addr |= 1; /* set bit 0 in address for thumb mode */ +#endif +#endif + vmalloc_sync_all_sym = (void *) addr; if (vmalloc_sync_all_sym) { vmalloc_sync_all_sym(); } else {
This patch fixes the undefined instruction oops due to execution of thumb-2 code in ARM mode. The zero bit in the symbol address returned by kallsyms_lookup_name is not set, leading to switching to ARM mode that generates oops while executing thumb-2 code. For detailed discussion, see [1]. [1] http://lists.casi.polymtl.ca/pipermail/ltt-dev/2011-September/005176.html Signed-off-by: Avik Sil <avik.sil@linaro.org> --- lttng-context-prio.c | 11 ++++++++++- wrapper/ftrace.h | 28 ++++++++++++++++++++++------ wrapper/splice.c | 14 ++++++++++++-- wrapper/vmalloc.h | 14 +++++++++++--- 4 files changed, 55 insertions(+), 12 deletions(-)