From: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> commit f1d3cbfaafc10464550c6d3a125f4fc802bbaed5 upstream. The functions: fetch_store_strlen_user() fetch_store_strlen() fetch_store_string_user() fetch_store_string() are identical in both trace_kprobe.c and trace_eprobe.c. Move them into a new header file trace_probe_kernel.h to share it. This code will later be used by the synthetic events as well. Marked for stable as a fix for a crash in synthetic events requires it. Link: https://lkml.kernel.org/r/20221012104534.467668078@xxxxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Tom Zanussi <zanussi@xxxxxxxxxx> Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> Reviewed-by: Tom Zanussi <zanussi@xxxxxxxxxx> Fixes: bd82631d7ccdc ("tracing: Add support for dynamic strings to synthetic events") Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/trace/trace_eprobe.c | 60 +---------------------- kernel/trace/trace_kprobe.c | 60 +---------------------- kernel/trace/trace_probe_kernel.h | 96 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 106 insertions(+), 110 deletions(-) create mode 100644 kernel/trace/trace_probe_kernel.h --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -16,6 +16,7 @@ #include "trace_dynevent.h" #include "trace_probe.h" #include "trace_probe_tmpl.h" +#include "trace_probe_kernel.h" #define EPROBE_EVENT_SYSTEM "eprobes" @@ -453,29 +454,14 @@ NOKPROBE_SYMBOL(process_fetch_insn) static nokprobe_inline int fetch_store_strlen_user(unsigned long addr) { - const void __user *uaddr = (__force const void __user *)addr; - - return strnlen_user_nofault(uaddr, MAX_STRING_SIZE); + return kern_fetch_store_strlen_user(addr); } /* Return the length of string -- including null terminal byte */ static nokprobe_inline int fetch_store_strlen(unsigned long addr) { - int ret, len = 0; - u8 c; - -#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE - if (addr < TASK_SIZE) - return fetch_store_strlen_user(addr); -#endif - - do { - ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1); - len++; - } while (c && ret == 0 && len < MAX_STRING_SIZE); - - return (ret < 0) ? ret : len; + return kern_fetch_store_strlen(addr); } /* @@ -485,21 +471,7 @@ fetch_store_strlen(unsigned long addr) static nokprobe_inline int fetch_store_string_user(unsigned long addr, void *dest, void *base) { - const void __user *uaddr = (__force const void __user *)addr; - int maxlen = get_loc_len(*(u32 *)dest); - void *__dest; - long ret; - - if (unlikely(!maxlen)) - return -ENOMEM; - - __dest = get_loc_data(dest, base); - - ret = strncpy_from_user_nofault(__dest, uaddr, maxlen); - if (ret >= 0) - *(u32 *)dest = make_data_loc(ret, __dest - base); - - return ret; + return kern_fetch_store_string_user(addr, dest, base); } /* @@ -509,29 +481,7 @@ fetch_store_string_user(unsigned long ad static nokprobe_inline int fetch_store_string(unsigned long addr, void *dest, void *base) { - int maxlen = get_loc_len(*(u32 *)dest); - void *__dest; - long ret; - -#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE - if ((unsigned long)addr < TASK_SIZE) - return fetch_store_string_user(addr, dest, base); -#endif - - if (unlikely(!maxlen)) - return -ENOMEM; - - __dest = get_loc_data(dest, base); - - /* - * Try to get string again, since the string can be changed while - * probing. - */ - ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen); - if (ret >= 0) - *(u32 *)dest = make_data_loc(ret, __dest - base); - - return ret; + return kern_fetch_store_string(addr, dest, base); } static nokprobe_inline int --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -20,6 +20,7 @@ #include "trace_kprobe_selftest.h" #include "trace_probe.h" #include "trace_probe_tmpl.h" +#include "trace_probe_kernel.h" #define KPROBE_EVENT_SYSTEM "kprobes" #define KRETPROBE_MAXACTIVE_MAX 4096 @@ -1223,29 +1224,14 @@ static const struct file_operations kpro static nokprobe_inline int fetch_store_strlen_user(unsigned long addr) { - const void __user *uaddr = (__force const void __user *)addr; - - return strnlen_user_nofault(uaddr, MAX_STRING_SIZE); + return kern_fetch_store_strlen_user(addr); } /* Return the length of string -- including null terminal byte */ static nokprobe_inline int fetch_store_strlen(unsigned long addr) { - int ret, len = 0; - u8 c; - -#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE - if (addr < TASK_SIZE) - return fetch_store_strlen_user(addr); -#endif - - do { - ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1); - len++; - } while (c && ret == 0 && len < MAX_STRING_SIZE); - - return (ret < 0) ? ret : len; + return kern_fetch_store_strlen(addr); } /* @@ -1255,21 +1241,7 @@ fetch_store_strlen(unsigned long addr) static nokprobe_inline int fetch_store_string_user(unsigned long addr, void *dest, void *base) { - const void __user *uaddr = (__force const void __user *)addr; - int maxlen = get_loc_len(*(u32 *)dest); - void *__dest; - long ret; - - if (unlikely(!maxlen)) - return -ENOMEM; - - __dest = get_loc_data(dest, base); - - ret = strncpy_from_user_nofault(__dest, uaddr, maxlen); - if (ret >= 0) - *(u32 *)dest = make_data_loc(ret, __dest - base); - - return ret; + return kern_fetch_store_string_user(addr, dest, base); } /* @@ -1279,29 +1251,7 @@ fetch_store_string_user(unsigned long ad static nokprobe_inline int fetch_store_string(unsigned long addr, void *dest, void *base) { - int maxlen = get_loc_len(*(u32 *)dest); - void *__dest; - long ret; - -#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE - if ((unsigned long)addr < TASK_SIZE) - return fetch_store_string_user(addr, dest, base); -#endif - - if (unlikely(!maxlen)) - return -ENOMEM; - - __dest = get_loc_data(dest, base); - - /* - * Try to get string again, since the string can be changed while - * probing. - */ - ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen); - if (ret >= 0) - *(u32 *)dest = make_data_loc(ret, __dest - base); - - return ret; + return kern_fetch_store_string(addr, dest, base); } static nokprobe_inline int --- /dev/null +++ b/kernel/trace/trace_probe_kernel.h @@ -0,0 +1,96 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __TRACE_PROBE_KERNEL_H_ +#define __TRACE_PROBE_KERNEL_H_ + +/* + * This depends on trace_probe.h, but can not include it due to + * the way trace_probe_tmpl.h is used by trace_kprobe.c and trace_eprobe.c. + * Which means that any other user must include trace_probe.h before including + * this file. + */ +/* Return the length of string -- including null terminal byte */ +static nokprobe_inline int +kern_fetch_store_strlen_user(unsigned long addr) +{ + const void __user *uaddr = (__force const void __user *)addr; + + return strnlen_user_nofault(uaddr, MAX_STRING_SIZE); +} + +/* Return the length of string -- including null terminal byte */ +static nokprobe_inline int +kern_fetch_store_strlen(unsigned long addr) +{ + int ret, len = 0; + u8 c; + +#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE + if (addr < TASK_SIZE) + return kern_fetch_store_strlen_user(addr); +#endif + + do { + ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1); + len++; + } while (c && ret == 0 && len < MAX_STRING_SIZE); + + return (ret < 0) ? ret : len; +} + +/* + * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf + * with max length and relative data location. + */ +static nokprobe_inline int +kern_fetch_store_string_user(unsigned long addr, void *dest, void *base) +{ + const void __user *uaddr = (__force const void __user *)addr; + int maxlen = get_loc_len(*(u32 *)dest); + void *__dest; + long ret; + + if (unlikely(!maxlen)) + return -ENOMEM; + + __dest = get_loc_data(dest, base); + + ret = strncpy_from_user_nofault(__dest, uaddr, maxlen); + if (ret >= 0) + *(u32 *)dest = make_data_loc(ret, __dest - base); + + return ret; +} + +/* + * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max + * length and relative data location. + */ +static nokprobe_inline int +kern_fetch_store_string(unsigned long addr, void *dest, void *base) +{ + int maxlen = get_loc_len(*(u32 *)dest); + void *__dest; + long ret; + +#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE + if ((unsigned long)addr < TASK_SIZE) + return kern_fetch_store_string_user(addr, dest, base); +#endif + + if (unlikely(!maxlen)) + return -ENOMEM; + + __dest = get_loc_data(dest, base); + + /* + * Try to get string again, since the string can be changed while + * probing. + */ + ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen); + if (ret >= 0) + *(u32 *)dest = make_data_loc(ret, __dest - base); + + return ret; +} + +#endif /* __TRACE_PROBE_KERNEL_H_ */
