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From: Matt Redfearn <matt.redfearn@imgtec.com>
To: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org, kernel-hardening@lists.openwall.com,
	Matt Redfearn <matt.redfearn@imgtec.com>,
	linux-kernel@vger.kernel.org, Jonas Gorski <jogo@openwrt.org>
Subject: [kernel-hardening] [PATCH v2 06/11] MIPS: Call relocate_kernel if CONFIG_RELOCATABLE=y
Date: Thu, 31 Mar 2016 10:05:37 +0100	[thread overview]
Message-ID: <1459415142-3412-7-git-send-email-matt.redfearn@imgtec.com> (raw)
In-Reply-To: <1459415142-3412-1-git-send-email-matt.redfearn@imgtec.com>

If CONFIG_RELOCATABLE is enabled, call relocate_kernel.

This function will return the entry point of the relocated kernel if
copy/relocate is sucessful or the original entry point if not. The stack
pointer must then be pointed into the new image.

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

Changes in v2: None

 arch/mips/kernel/head.S | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S
index 4e4cc5b9a771..7dc043349d66 100644
--- a/arch/mips/kernel/head.S
+++ b/arch/mips/kernel/head.S
@@ -132,7 +132,27 @@ not_found:
 	set_saved_sp	sp, t0, t1
 	PTR_SUBU	sp, 4 * SZREG		# init stack pointer
 
+#ifdef CONFIG_RELOCATABLE
+	/* Copy kernel and apply the relocations */
+	jal		relocate_kernel
+
+	/* Repoint the sp into the new kernel image */
+	PTR_LI		sp, _THREAD_SIZE - 32 - PT_SIZE
+	PTR_ADDU	sp, $28
+	set_saved_sp	sp, t0, t1
+	PTR_SUBU	sp, 4 * SZREG		# init stack pointer
+
+	/*
+	 * relocate_kernel returns the entry point either
+	 * in the relocated kernel or the original if for
+	 * some reason relocation failed - jump there now
+	 * with instruction hazard barrier because of the
+	 * newly sync'd icache.
+	 */
+	jr.hb		v0
+#else
 	j		start_kernel
+#endif
 	END(kernel_entry)
 
 #ifdef CONFIG_SMP
-- 
2.5.0

  parent reply	other threads:[~2016-03-31  9:05 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-31  9:05 [kernel-hardening] [PATCH v2 00/11] MIPS relocatable kernel & KASLR Matt Redfearn
2016-03-31  9:05 ` [kernel-hardening] [PATCH v2 01/11] MIPS: tools: Add relocs tool Matt Redfearn
2016-03-31  9:05 ` [kernel-hardening] [PATCH v2 02/11] MIPS: tools: Build " Matt Redfearn
2016-03-31  9:05 ` [kernel-hardening] [PATCH v2 03/11] MIPS: Reserve space for relocation table Matt Redfearn
2016-03-31  9:05 ` [kernel-hardening] [PATCH v2 04/11] MIPS: Generate relocation table when CONFIG_RELOCATABLE Matt Redfearn
2016-03-31  9:05 ` [kernel-hardening] [PATCH v2 05/11] MIPS: Kernel: Add relocate.c Matt Redfearn
2016-03-31  9:05 ` Matt Redfearn [this message]
2016-03-31  9:05 ` [kernel-hardening] [PATCH v2 07/11] MIPS: bootmem: When relocatable, free memory below kernel Matt Redfearn
2016-03-31  9:05 ` [kernel-hardening] [PATCH v2 08/11] MIPS: Add CONFIG_RELOCATABLE Kconfig option Matt Redfearn
2016-03-31  9:05 ` [kernel-hardening] [PATCH v2 09/11] MIPS: Introduce plat_get_fdt a platform API to retrieve the FDT Matt Redfearn
2016-03-31  9:05 ` [kernel-hardening] [PATCH v2 10/11] MIPS: Kernel: Implement KASLR using CONFIG_RELOCATABLE Matt Redfearn
2016-03-31  9:05 ` [kernel-hardening] [PATCH v2 11/11] MIPS: KASLR: Print relocation Information on boot Matt Redfearn
2016-03-31 12:38   ` [kernel-hardening] " Sergei Shtylyov
2016-04-01  8:44     ` Ralf Baechle
2016-04-01  9:07       ` Matt Redfearn
2016-04-04 19:46 ` [kernel-hardening] [PATCH v2 00/11] MIPS relocatable kernel & KASLR Kees Cook
2016-04-04 23:37   ` Ralf Baechle
2016-04-04 23:56     ` Kees Cook
2016-04-05  9:09       ` James Hogan
2016-04-05 18:10         ` Kees Cook
2016-04-05 21:00           ` James Hogan
2016-04-05 12:14     ` Maciej W. Rozycki

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