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860e8fbde4
commitf1d3cbfaafupstream. 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@goodmis.org Cc: stable@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tom Zanussi <zanussi@kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Fixes:bd82631d7c("tracing: Add support for dynamic strings to synthetic events") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
97 lines
2.4 KiB
C
97 lines
2.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __TRACE_PROBE_KERNEL_H_
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#define __TRACE_PROBE_KERNEL_H_
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/*
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* This depends on trace_probe.h, but can not include it due to
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* the way trace_probe_tmpl.h is used by trace_kprobe.c and trace_eprobe.c.
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* Which means that any other user must include trace_probe.h before including
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* this file.
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*/
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/* Return the length of string -- including null terminal byte */
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static nokprobe_inline int
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kern_fetch_store_strlen_user(unsigned long addr)
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{
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const void __user *uaddr = (__force const void __user *)addr;
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return strnlen_user_nofault(uaddr, MAX_STRING_SIZE);
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}
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/* Return the length of string -- including null terminal byte */
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static nokprobe_inline int
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kern_fetch_store_strlen(unsigned long addr)
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{
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int ret, len = 0;
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u8 c;
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#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
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if (addr < TASK_SIZE)
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return kern_fetch_store_strlen_user(addr);
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#endif
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do {
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ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1);
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len++;
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} while (c && ret == 0 && len < MAX_STRING_SIZE);
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return (ret < 0) ? ret : len;
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}
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/*
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* Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
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* with max length and relative data location.
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*/
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static nokprobe_inline int
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kern_fetch_store_string_user(unsigned long addr, void *dest, void *base)
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{
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const void __user *uaddr = (__force const void __user *)addr;
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int maxlen = get_loc_len(*(u32 *)dest);
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void *__dest;
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long ret;
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if (unlikely(!maxlen))
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return -ENOMEM;
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__dest = get_loc_data(dest, base);
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ret = strncpy_from_user_nofault(__dest, uaddr, maxlen);
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if (ret >= 0)
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*(u32 *)dest = make_data_loc(ret, __dest - base);
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return ret;
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}
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/*
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* Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
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* length and relative data location.
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*/
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static nokprobe_inline int
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kern_fetch_store_string(unsigned long addr, void *dest, void *base)
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{
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int maxlen = get_loc_len(*(u32 *)dest);
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void *__dest;
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long ret;
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#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
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if ((unsigned long)addr < TASK_SIZE)
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return kern_fetch_store_string_user(addr, dest, base);
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#endif
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if (unlikely(!maxlen))
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return -ENOMEM;
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__dest = get_loc_data(dest, base);
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/*
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* Try to get string again, since the string can be changed while
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* probing.
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*/
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ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen);
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if (ret >= 0)
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*(u32 *)dest = make_data_loc(ret, __dest - base);
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return ret;
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}
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#endif /* __TRACE_PROBE_KERNEL_H_ */
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