linux.git/arch/powerpc/include/asm/livepatch.h, branch v5.1 Linux kernel source tree powerpc: Activate CONFIG_THREAD_INFO_IN_TASK 2019-02-23T11:31:40+00:00 Christophe Leroy christophe.leroy@c-s.fr 2019-01-31T10:08:58+00:00 ed1cd6deb013a11959d17a94e35ce159197632da This patch activates CONFIG_THREAD_INFO_IN_TASK which moves the thread_info into task_struct. Moving thread_info into task_struct has the following advantages: - It protects thread_info from corruption in the case of stack overflows. - Its address is harder to determine if stack addresses are leaked, making a number of attacks more difficult. This has the following consequences: - thread_info is now located at the beginning of task_struct. - The 'cpu' field is now in task_struct, and only exists when CONFIG_SMP is active. - thread_info doesn't have anymore the 'task' field. This patch: - Removes all recopy of thread_info struct when the stack changes. - Changes the CURRENT_THREAD_INFO() macro to point to current. - Selects CONFIG_THREAD_INFO_IN_TASK. - Modifies raw_smp_processor_id() to get ->cpu from current without including linux/sched.h to avoid circular inclusion and without including asm/asm-offsets.h to avoid symbol names duplication between ASM constants and C constants. - Modifies klp_init_thread_info() to take a task_struct pointer argument. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Add task_stack.h to livepatch.h to fix build fails] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
This patch activates CONFIG_THREAD_INFO_IN_TASK which
moves the thread_info into task_struct.

Moving thread_info into task_struct has the following advantages:
  - It protects thread_info from corruption in the case of stack
    overflows.
  - Its address is harder to determine if stack addresses are leaked,
    making a number of attacks more difficult.

This has the following consequences:
  - thread_info is now located at the beginning of task_struct.
  - The 'cpu' field is now in task_struct, and only exists when
    CONFIG_SMP is active.
  - thread_info doesn't have anymore the 'task' field.

This patch:
  - Removes all recopy of thread_info struct when the stack changes.
  - Changes the CURRENT_THREAD_INFO() macro to point to current.
  - Selects CONFIG_THREAD_INFO_IN_TASK.
  - Modifies raw_smp_processor_id() to get ->cpu from current without
    including linux/sched.h to avoid circular inclusion and without
    including asm/asm-offsets.h to avoid symbol names duplication
    between ASM constants and C constants.
  - Modifies klp_init_thread_info() to take a task_struct pointer
    argument.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Add task_stack.h to livepatch.h to fix build fails]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/livepatch: Remove klp_write_module_reloc() stub 2016-12-19T10:15:25+00:00 Kamalesh Babulal kamalesh@linux.vnet.ibm.com 2016-12-16T06:14:24+00:00 b766922e65356df38a57b09afab6c3d7bf7e024d commit 425595a7fc20 ("livepatch: reuse module loader code to write relocations") offloads livepatch module relocation write to arch specific module loader code. Remove unused klp_write_module_reloc() function stub. Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> 
commit 425595a7fc20 ("livepatch: reuse module loader code
to write relocations") offloads livepatch module relocation
write to arch specific module loader code.

Remove unused klp_write_module_reloc() function stub.

Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
powerpc/livepatch: Add livepatch stack to struct thread_info 2016-04-14T05:47:06+00:00 Michael Ellerman mpe@ellerman.id.au 2016-03-24T11:04:04+00:00 5d31a96e6c0187f2c5d7004e005fd094a1277e9e In order to support live patching we need to maintain an alternate stack of TOC & LR values. We use the base of the stack for this, and store the "live patch stack pointer" in struct thread_info. Unlike the other fields of thread_info, we can not statically initialise that value, so it must be done at run time. This patch just adds the code to support that, it is not enabled until the next patch which actually adds live patch support. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Balbir Singh <bsingharora@gmail.com> 
In order to support live patching we need to maintain an alternate
stack of TOC & LR values. We use the base of the stack for this, and
store the "live patch stack pointer" in struct thread_info.

Unlike the other fields of thread_info, we can not statically initialise
that value, so it must be done at run time.

This patch just adds the code to support that, it is not enabled until
the next patch which actually adds live patch support.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Balbir Singh <bsingharora@gmail.com>
powerpc/livepatch: Add livepatch header 2016-04-14T05:47:06+00:00 Michael Ellerman mpe@ellerman.id.au 2016-03-24T11:04:03+00:00 f63e6d89876034c21ecd18bb1cd0d6c5b8da11a5 Add the powerpc specific livepatch definitions. In particular we provide a non-default implementation of klp_get_ftrace_location(). This is required because the location of the mcount call is not constant when using -mprofile-kernel (which we always do for live patching). Signed-off-by: Torsten Duwe <duwe@suse.de> Signed-off-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
Add the powerpc specific livepatch definitions. In particular we provide
a non-default implementation of klp_get_ftrace_location().

This is required because the location of the mcount call is not constant
when using -mprofile-kernel (which we always do for live patching).

Signed-off-by: Torsten Duwe <duwe@suse.de>
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>