bee9946688
[ Upstream commit 4ed8f337dee32df71435689c19d22e4ee846e15a ] This reverts commit2e9906f84f. It was turned out that commit2e9906f84f("tracing: Add "(fault)" name injection to kernel probes") did not work correctly and probe events still show just '(fault)' (instead of '"(fault)"'). Also, current '(fault)' is more explicit that it faulted. This also moves FAULT_STRING macro to trace.h so that synthetic event can keep using it, and uses it in trace_probe.c too. Link: https://lore.kernel.org/all/168908495772.123124.1250788051922100079.stgit@devnote2/ Link: https://lore.kernel.org/all/20230706230642.3793a593@rorschach.local.home/ Cc: stable@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Stable-dep-of: 797311bce5c2 ("tracing/probes: Fix to record 0-length data_loc in fetch_store_string*() if fails") Signed-off-by: Sasha Levin <sashal@kernel.org>
96 lines
2.4 KiB
C
96 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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