lkml.org 
[lkml]   [2014]   [Feb]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC PATCH v2 tip 4/7] Revert "x86/ptrace: Remove unused regs_get_argument_nth API"
Date
This reverts commit aa5add93e92019018e905146f8c3d3f8e3c08300.

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
---
arch/x86/include/asm/ptrace.h | 3 +++
arch/x86/kernel/ptrace.c | 24 ++++++++++++++++++++++++
2 files changed, 27 insertions(+)

diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 14fd6fd..e026176 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -222,6 +222,9 @@ static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
return 0;
}

+/* Get Nth argument at function call */
+unsigned long regs_get_argument_nth(struct pt_regs *regs, unsigned int n);
+
#define arch_has_single_step() (1)
#ifdef CONFIG_X86_DEBUGCTLMSR
#define arch_has_block_step() (1)
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 7461f50..ac1c705 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -141,6 +141,30 @@ static const int arg_offs_table[] = {
#endif
};

+/**
+ * regs_get_argument_nth() - get Nth argument at function call
+ * @regs: pt_regs which contains registers at function entry.
+ * @n: argument number.
+ *
+ * regs_get_argument_nth() returns @n th argument of a function call.
+ * Since usually the kernel stack will be changed right after function entry,
+ * you must use this at function entry. If the @n th entry is NOT in the
+ * kernel stack or pt_regs, this returns 0.
+ */
+unsigned long regs_get_argument_nth(struct pt_regs *regs, unsigned int n)
+{
+ if (n < ARRAY_SIZE(arg_offs_table))
+ return *(unsigned long *)((char *)regs + arg_offs_table[n]);
+ else {
+ /*
+ * The typical case: arg n is on the stack.
+ * (Note: stack[0] = return address, so skip it)
+ */
+ n -= ARRAY_SIZE(arg_offs_table);
+ return regs_get_kernel_stack_nth(regs, 1 + n);
+ }
+}
+
/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
--
1.7.9.5


\
 
 \ /
  Last update: 2014-02-06 02:21    [W:0.043 / U:13.688 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site