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Namhyung Kimrostedt
Namhyung Kim
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tracing/probes: Implement 'stack' fetch method for uprobes
Use separate method to fetch from stack. Move existing functions to trace_kprobe.c and make them static. Also add new stack fetch implementation for uprobes. Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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4 files changed

+66
-26
lines changed

4 files changed

+66
-26
lines changed

‎kernel/trace/trace_kprobe.c

Lines changed: 15 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -88,6 +88,21 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
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static int kretprobe_dispatcher(struct kretprobe_instance *ri,
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struct pt_regs *regs);
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/*
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* Kprobes-specific fetch functions
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*/
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#define DEFINE_FETCH_stack(type) \
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static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
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void *offset, void *dest) \
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{ \
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*(type *)dest = (type)regs_get_kernel_stack_nth(regs, \
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(unsigned int)((unsigned long)offset)); \
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}
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DEFINE_BASIC_FETCH_FUNCS(stack)
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/* No string on the stack entry */
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#define fetch_stack_string NULL
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#define fetch_stack_string_size NULL
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/* Fetch type information table */
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const struct fetch_type kprobes_fetch_type_table[] = {
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/* Special types */

‎kernel/trace/trace_probe.c

Lines changed: 0 additions & 22 deletions
Original file line numberDiff line numberDiff line change
@@ -70,16 +70,6 @@ __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
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const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
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73-
/*
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* Define macro for basic types - we don't need to define s* types, because
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* we have to care only about bitwidth at recording time.
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*/
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#define DEFINE_BASIC_FETCH_FUNCS(method) \
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DEFINE_FETCH_##method(u8) \
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DEFINE_FETCH_##method(u16) \
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DEFINE_FETCH_##method(u32) \
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DEFINE_FETCH_##method(u64)
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#define CHECK_FETCH_FUNCS(method, fn) \
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(((FETCH_FUNC_NAME(method, u8) == fn) || \
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(FETCH_FUNC_NAME(method, u16) == fn) || \
@@ -102,18 +92,6 @@ DEFINE_BASIC_FETCH_FUNCS(reg)
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#define fetch_reg_string NULL
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#define fetch_reg_string_size NULL
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#define DEFINE_FETCH_stack(type) \
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__kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \
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void *offset, void *dest) \
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{ \
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*(type *)dest = (type)regs_get_kernel_stack_nth(regs, \
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(unsigned int)((unsigned long)offset)); \
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}
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DEFINE_BASIC_FETCH_FUNCS(stack)
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/* No string on the stack entry */
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#define fetch_stack_string NULL
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#define fetch_stack_string_size NULL
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#define DEFINE_FETCH_retval(type) \
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__kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \
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void *dummy, void *dest) \

‎kernel/trace/trace_probe.h

Lines changed: 10 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -167,10 +167,6 @@ DECLARE_BASIC_FETCH_FUNCS(reg);
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#define fetch_reg_string NULL
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#define fetch_reg_string_size NULL
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DECLARE_BASIC_FETCH_FUNCS(stack);
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#define fetch_stack_string NULL
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#define fetch_stack_string_size NULL
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DECLARE_BASIC_FETCH_FUNCS(retval);
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#define fetch_retval_string NULL
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#define fetch_retval_string_size NULL
@@ -191,6 +187,16 @@ DECLARE_BASIC_FETCH_FUNCS(bitfield);
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#define fetch_bitfield_string NULL
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#define fetch_bitfield_string_size NULL
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/*
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* Define macro for basic types - we don't need to define s* types, because
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* we have to care only about bitwidth at recording time.
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*/
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#define DEFINE_BASIC_FETCH_FUNCS(method) \
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DEFINE_FETCH_##method(u8) \
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DEFINE_FETCH_##method(u16) \
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DEFINE_FETCH_##method(u32) \
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DEFINE_FETCH_##method(u64)
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/* Default (unsigned long) fetch type */
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#define __DEFAULT_FETCH_TYPE(t) u##t
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#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)

‎kernel/trace/trace_uprobe.c

Lines changed: 41 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -74,6 +74,47 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
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static int uretprobe_dispatcher(struct uprobe_consumer *con,
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unsigned long func, struct pt_regs *regs);
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#ifdef CONFIG_STACK_GROWSUP
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static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
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{
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return addr - (n * sizeof(long));
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}
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#else
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static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
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{
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return addr + (n * sizeof(long));
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}
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#endif
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static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
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{
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unsigned long ret;
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unsigned long addr = user_stack_pointer(regs);
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addr = adjust_stack_addr(addr, n);
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if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
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return 0;
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return ret;
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}
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/*
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* Uprobes-specific fetch functions
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*/
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#define DEFINE_FETCH_stack(type) \
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static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
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void *offset, void *dest) \
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{ \
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*(type *)dest = (type)get_user_stack_nth(regs, \
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((unsigned long)offset)); \
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}
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DEFINE_BASIC_FETCH_FUNCS(stack)
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/* No string on the stack entry */
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#define fetch_stack_string NULL
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#define fetch_stack_string_size NULL
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/* Fetch type information table */
78119
const struct fetch_type uprobes_fetch_type_table[] = {
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/* Special types */

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