[PATCH v2 11/11] MIPS: KASLR: Print relocation Information on boot

From	Matt Redfearn <matt.redfearn@imgtec.com>
Newsgroups	linux.kernel
Subject	[PATCH v2 11/11] MIPS: KASLR: Print relocation Information on boot
Date	2016-03-31 11:20 +0200
Message-ID	<riGVI-2I1-17@gated-at.bofh.it> (permalink)
References	<riGVH-2I1-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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When debugging a relocated kernel, the addresses of the relocated
symbols and the offset applied is essential information. If the kernel
is compiled with debugging information, then print this information
during bootup using the same function as the panic notifer.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
---

Changes in v2: None

 arch/mips/kernel/setup.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index d8376d7b3345..ae71f8d9b555 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -477,9 +477,18 @@ static void __init bootmem_init(void)
 	 */
 	if (__pa_symbol(_text) > __pa_symbol(VMLINUX_LOAD_ADDRESS)) {
 		unsigned long offset;
+		extern void show_kernel_relocation(const char *level);
 
 		offset = __pa_symbol(_text) - __pa_symbol(VMLINUX_LOAD_ADDRESS);
 		free_bootmem(__pa_symbol(VMLINUX_LOAD_ADDRESS), offset);
+
+#if (defined CONFIG_DEBUG_KERNEL) && (defined CONFIG_DEBUG_INFO)
+		/*
+		 * This information is necessary when debugging the kernel
+		 * But is a security vulnerability otherwise!
+		 */
+		show_kernel_relocation(KERN_INFO);
+#endif
 	}
 #endif
 
-- 
2.5.0

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[PATCH v2 11/11] MIPS: KASLR: Print relocation Information on boot Matt Redfearn <matt.redfearn@imgtec.com> - 2016-03-31 11:20 +0200
  Re: [PATCH v2 11/11] MIPS: KASLR: Print relocation Information on  boot Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> - 2016-03-31 14:40 +0200
    Re: [PATCH v2 11/11] MIPS: KASLR: Print relocation Information on  boot Ralf Baechle <ralf@linux-mips.org> - 2016-04-01 10:50 +0200
      Re: [PATCH v2 11/11] MIPS: KASLR: Print relocation Information on  boot Matt Redfearn <matt.redfearn@imgtec.com> - 2016-04-01 11:10 +0200

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