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linux/arch/powerpc/lib/code-patching.c

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powerpc: Move code patching code into arch/powerpc/lib/code-patching.c We currently have a few routines for patching code in asm/system.h, because they didn't fit anywhere else. I'd like to clean them up a little and add some more, so first move them into a dedicated C file - they don't need to be inlined. While we're moving the code, drop create_function_call(), it's intended caller never got merged and will be replaced in future with something different. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:21 +10:00
powerpc: Add tests of the code patching routines Add tests of the existing code patching routines, as well as the new routines added in the last commit. The self-tests are run late in boot when CONFIG_CODE_PATCHING_SELFTEST=y, which depends on DEBUG_KERNEL=y. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:32 +10:00
PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures On 32-bit architectures PAGE_ALIGN() truncates 64-bit values to the 32-bit boundary. For example: u64 val = PAGE_ALIGN(size); always returns a value < 4GB even if size is greater than 4GB. The problem resides in PAGE_MASK definition (from include/asm-x86/page.h for example): #define PAGE_SHIFT 12 #define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT) #define PAGE_MASK (~(PAGE_SIZE-1)) ... #define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK) The "~" is performed on a 32-bit value, so everything in "and" with PAGE_MASK greater than 4GB will be truncated to the 32-bit boundary. Using the ALIGN() macro seems to be the right way, because it uses typeof(addr) for the mask. Also move the PAGE_ALIGN() definitions out of include/asm-*/page.h in include/linux/mm.h. See also lkml discussion: http://lkml.org/lkml/2008/6/11/237 [akpm@linux-foundation.org: fix drivers/media/video/uvc/uvc_queue.c] [akpm@linux-foundation.org: fix v850] [akpm@linux-foundation.org: fix powerpc] [akpm@linux-foundation.org: fix arm] [akpm@linux-foundation.org: fix mips] [akpm@linux-foundation.org: fix drivers/media/video/pvrusb2/pvrusb2-dvb.c] [akpm@linux-foundation.org: fix drivers/mtd/maps/uclinux.c] [akpm@linux-foundation.org: fix powerpc] Signed-off-by: Andrea Righi <righi.andrea@gmail.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-23 21:28:13 -07:00
powerpc: Add tests of the code patching routines Add tests of the existing code patching routines, as well as the new routines added in the last commit. The self-tests are run late in boot when CONFIG_CODE_PATCHING_SELFTEST=y, which depends on DEBUG_KERNEL=y. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:32 +10:00
powerpc: Move code patching code into arch/powerpc/lib/code-patching.c We currently have a few routines for patching code in asm/system.h, because they didn't fit anywhere else. I'd like to clean them up a little and add some more, so first move them into a dedicated C file - they don't need to be inlined. While we're moving the code, drop create_function_call(), it's intended caller never got merged and will be replaced in future with something different. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:21 +10:00
powerpc: Have patch_instruction detect faults For ftrace to use the patch_instruction code, it needs to check for faults on write. Ftrace updates code all over the kernel, and we need to know if code is updated or not due to protections that are placed on some portions of the kernel. If ftrace does not detect a fault, it will error later on, and it will be much more difficult to find the problem. By changing patch_instruction() to detect faults, then ftrace will be able to make use of it too. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-04-26 08:31:18 +00:00
powerpc: Move code patching code into arch/powerpc/lib/code-patching.c We currently have a few routines for patching code in asm/system.h, because they didn't fit anywhere else. I'd like to clean them up a little and add some more, so first move them into a dedicated C file - they don't need to be inlined. While we're moving the code, drop create_function_call(), it's intended caller never got merged and will be replaced in future with something different. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:21 +10:00
powerpc: Have patch_instruction detect faults For ftrace to use the patch_instruction code, it needs to check for faults on write. Ftrace updates code all over the kernel, and we need to know if code is updated or not due to protections that are placed on some portions of the kernel. If ftrace does not detect a fault, it will error later on, and it will be much more difficult to find the problem. By changing patch_instruction() to detect faults, then ftrace will be able to make use of it too. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-04-26 08:31:18 +00:00
powerpc: Move code patching code into arch/powerpc/lib/code-patching.c We currently have a few routines for patching code in asm/system.h, because they didn't fit anywhere else. I'd like to clean them up a little and add some more, so first move them into a dedicated C file - they don't need to be inlined. While we're moving the code, drop create_function_call(), it's intended caller never got merged and will be replaced in future with something different. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:21 +10:00
powerpc: Have patch_instruction detect faults For ftrace to use the patch_instruction code, it needs to check for faults on write. Ftrace updates code all over the kernel, and we need to know if code is updated or not due to protections that are placed on some portions of the kernel. If ftrace does not detect a fault, it will error later on, and it will be much more difficult to find the problem. By changing patch_instruction() to detect faults, then ftrace will be able to make use of it too. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-04-26 08:31:18 +00:00
powerpc: Don't use __put_user() in patch_instruction patch_instruction() can be called very early on ppc32, when the kernel isn't yet running at it's linked address. That can cause the ! is_kernel_addr() test in __put_user() to trip and call might_sleep() which is very bad at that point during boot. Use a lower level function instead for now, at least until we get to rework ppc32 boot process to do the code patching later, like ppc64 does. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-04 15:08:28 +00:00
powerpc: Have patch_instruction detect faults For ftrace to use the patch_instruction code, it needs to check for faults on write. Ftrace updates code all over the kernel, and we need to know if code is updated or not due to protections that are placed on some portions of the kernel. If ftrace does not detect a fault, it will error later on, and it will be much more difficult to find the problem. By changing patch_instruction() to detect faults, then ftrace will be able to make use of it too. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-04-26 08:31:18 +00:00
powerpc: Allow create_branch() to return errors Currently create_branch() creates a branch instruction for you, and patches it into the call site. In some circumstances it would be nice to be able to create the instruction and patch it later, and also some code might want to check for errors in the branch creation before doing the patching. A future commit will change create_branch() to check for errors. For callers that don't care, replace create_branch() with patch_branch(), which just creates the branch and patches it directly. While we're touching all the callers, change to using unsigned int *, as this seems to match usage better. That allows (and requires) us to remove the volatile in the definition of vector in powermac/smp.c and mpc86xx_smp.c, that's correct because now that we're passing vector as an unsigned int * the compiler knows that it's value might change across the patch_branch() call. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Acked-by: Jon Loeliger <jdl@freescale.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:22 +10:00
powerpc: Have patch_instruction detect faults For ftrace to use the patch_instruction code, it needs to check for faults on write. Ftrace updates code all over the kernel, and we need to know if code is updated or not due to protections that are placed on some portions of the kernel. If ftrace does not detect a fault, it will error later on, and it will be much more difficult to find the problem. By changing patch_instruction() to detect faults, then ftrace will be able to make use of it too. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-04-26 08:31:18 +00:00
powerpc: Move code patching code into arch/powerpc/lib/code-patching.c We currently have a few routines for patching code in asm/system.h, because they didn't fit anywhere else. I'd like to clean them up a little and add some more, so first move them into a dedicated C file - they don't need to be inlined. While we're moving the code, drop create_function_call(), it's intended caller never got merged and will be replaced in future with something different. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:21 +10:00
powerpc: Have patch_instruction detect faults For ftrace to use the patch_instruction code, it needs to check for faults on write. Ftrace updates code all over the kernel, and we need to know if code is updated or not due to protections that are placed on some portions of the kernel. If ftrace does not detect a fault, it will error later on, and it will be much more difficult to find the problem. By changing patch_instruction() to detect faults, then ftrace will be able to make use of it too. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-04-26 08:31:18 +00:00
powerpc: Allow create_branch() to return errors Currently create_branch() creates a branch instruction for you, and patches it into the call site. In some circumstances it would be nice to be able to create the instruction and patch it later, and also some code might want to check for errors in the branch creation before doing the patching. A future commit will change create_branch() to check for errors. For callers that don't care, replace create_branch() with patch_branch(), which just creates the branch and patches it directly. While we're touching all the callers, change to using unsigned int *, as this seems to match usage better. That allows (and requires) us to remove the volatile in the definition of vector in powermac/smp.c and mpc86xx_smp.c, that's correct because now that we're passing vector as an unsigned int * the compiler knows that it's value might change across the patch_branch() call. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Acked-by: Jon Loeliger <jdl@freescale.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:22 +10:00
powerpc: Have patch_instruction detect faults For ftrace to use the patch_instruction code, it needs to check for faults on write. Ftrace updates code all over the kernel, and we need to know if code is updated or not due to protections that are placed on some portions of the kernel. If ftrace does not detect a fault, it will error later on, and it will be much more difficult to find the problem. By changing patch_instruction() to detect faults, then ftrace will be able to make use of it too. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-04-26 08:31:18 +00:00
powerpc: Allow create_branch() to return errors Currently create_branch() creates a branch instruction for you, and patches it into the call site. In some circumstances it would be nice to be able to create the instruction and patch it later, and also some code might want to check for errors in the branch creation before doing the patching. A future commit will change create_branch() to check for errors. For callers that don't care, replace create_branch() with patch_branch(), which just creates the branch and patches it directly. While we're touching all the callers, change to using unsigned int *, as this seems to match usage better. That allows (and requires) us to remove the volatile in the definition of vector in powermac/smp.c and mpc86xx_smp.c, that's correct because now that we're passing vector as an unsigned int * the compiler knows that it's value might change across the patch_branch() call. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Acked-by: Jon Loeliger <jdl@freescale.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:22 +10:00
powerpc: Move code patching code into arch/powerpc/lib/code-patching.c We currently have a few routines for patching code in asm/system.h, because they didn't fit anywhere else. I'd like to clean them up a little and add some more, so first move them into a dedicated C file - they don't need to be inlined. While we're moving the code, drop create_function_call(), it's intended caller never got merged and will be replaced in future with something different. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:21 +10:00
powerpc: Make create_branch() return errors if the branch target is too large If you pass a target value to create_branch() which is more than 32MB - 4, or - 32MB away from the branch site, then it's impossible to create an immediate branch. The current code doesn't check, which will lead to us creating a branch to somewhere else - which is bad. For code that cares to check we return 0, which is easy to check for, and for code that doesn't at least we'll be creating an illegal instruction, rather than a branch to some random address. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:24 +10:00
powerpc: Move code patching code into arch/powerpc/lib/code-patching.c We currently have a few routines for patching code in asm/system.h, because they didn't fit anywhere else. I'd like to clean them up a little and add some more, so first move them into a dedicated C file - they don't need to be inlined. While we're moving the code, drop create_function_call(), it's intended caller never got merged and will be replaced in future with something different. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:21 +10:00
powerpc: Make create_branch() return errors if the branch target is too large If you pass a target value to create_branch() which is more than 32MB - 4, or - 32MB away from the branch site, then it's impossible to create an immediate branch. The current code doesn't check, which will lead to us creating a branch to somewhere else - which is bad. For code that cares to check we return 0, which is easy to check for, and for code that doesn't at least we'll be creating an illegal instruction, rather than a branch to some random address. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:24 +10:00
powerpc: Move code patching code into arch/powerpc/lib/code-patching.c We currently have a few routines for patching code in asm/system.h, because they didn't fit anywhere else. I'd like to clean them up a little and add some more, so first move them into a dedicated C file - they don't need to be inlined. While we're moving the code, drop create_function_call(), it's intended caller never got merged and will be replaced in future with something different. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:21 +10:00
powerpc: Make create_branch() return errors if the branch target is too large If you pass a target value to create_branch() which is more than 32MB - 4, or - 32MB away from the branch site, then it's impossible to create an immediate branch. The current code doesn't check, which will lead to us creating a branch to somewhere else - which is bad. For code that cares to check we return 0, which is easy to check for, and for code that doesn't at least we'll be creating an illegal instruction, rather than a branch to some random address. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:24 +10:00
powerpc: Move code patching code into arch/powerpc/lib/code-patching.c We currently have a few routines for patching code in asm/system.h, because they didn't fit anywhere else. I'd like to clean them up a little and add some more, so first move them into a dedicated C file - they don't need to be inlined. While we're moving the code, drop create_function_call(), it's intended caller never got merged and will be replaced in future with something different. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:21 +10:00
powerpc: Make create_branch() return errors if the branch target is too large If you pass a target value to create_branch() which is more than 32MB - 4, or - 32MB away from the branch site, then it's impossible to create an immediate branch. The current code doesn't check, which will lead to us creating a branch to somewhere else - which is bad. For code that cares to check we return 0, which is easy to check for, and for code that doesn't at least we'll be creating an illegal instruction, rather than a branch to some random address. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:24 +10:00
powerpc: Move code patching code into arch/powerpc/lib/code-patching.c We currently have a few routines for patching code in asm/system.h, because they didn't fit anywhere else. I'd like to clean them up a little and add some more, so first move them into a dedicated C file - they don't need to be inlined. While we're moving the code, drop create_function_call(), it's intended caller never got merged and will be replaced in future with something different. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:21 +10:00
powerpc: Allow create_branch() to return errors Currently create_branch() creates a branch instruction for you, and patches it into the call site. In some circumstances it would be nice to be able to create the instruction and patch it later, and also some code might want to check for errors in the branch creation before doing the patching. A future commit will change create_branch() to check for errors. For callers that don't care, replace create_branch() with patch_branch(), which just creates the branch and patches it directly. While we're touching all the callers, change to using unsigned int *, as this seems to match usage better. That allows (and requires) us to remove the volatile in the definition of vector in powermac/smp.c and mpc86xx_smp.c, that's correct because now that we're passing vector as an unsigned int * the compiler knows that it's value might change across the patch_branch() call. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Acked-by: Jon Loeliger <jdl@freescale.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:22 +10:00
powerpc: Move code patching code into arch/powerpc/lib/code-patching.c We currently have a few routines for patching code in asm/system.h, because they didn't fit anywhere else. I'd like to clean them up a little and add some more, so first move them into a dedicated C file - they don't need to be inlined. While we're moving the code, drop create_function_call(), it's intended caller never got merged and will be replaced in future with something different. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:21 +10:00
powerpc: Add new code patching routines This commit adds some new routines for patching code, which will be used in a following commit. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:29 +10:00
powerpc: Add tests of the code patching routines Add tests of the existing code patching routines, as well as the new routines added in the last commit. The self-tests are run late in boot when CONFIG_CODE_PATCHING_SELFTEST=y, which depends on DEBUG_KERNEL=y. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:32 +10:00
powerpc: Move the patch_exception to a common place So that it can be used by other codes. No function change. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-12 07:26:22 +08:00
powerpc: Add tests of the code patching routines Add tests of the existing code patching routines, as well as the new routines added in the last commit. The self-tests are run late in boot when CONFIG_CODE_PATCHING_SELFTEST=y, which depends on DEBUG_KERNEL=y. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 11:32:32 +10:00