kernel.git/arch/powerpc/kernel/head_booke.h, branch linux-5.3.y

powerpc/32: fix build failure on book3e with KVM

2019-06-15T14:03:38Z

Build failure was introduced by the commit identified below, due to missed macro expension leading to wrong called function's name. arch/powerpc/kernel/head_fsl_booke.o: In function `SystemCall': arch/powerpc/kernel/head_fsl_booke.S:416: undefined reference to `kvmppc_handler_BOOKE_INTERRUPT_SYSCALL_SPRN_SRR1' Makefile:1052: recipe for target 'vmlinux' failed The called function should be kvmppc_handler_8_0x01B(). This patch fixes it. Reported-by: Paul Mackerras Fixes: 1a4b739bbb4f ("powerpc/32: implement fast entry for syscalls on BOOKE") Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc/booke: fix fast syscall entry on SMP

2019-06-15T13:44:41Z

Use r10 instead of r9 to calculate CPU offset as r9 contains the value from SRR1 which is used later. Fixes: 1a4b739bbb4f ("powerpc/32: implement fast entry for syscalls on BOOKE") Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc/32: implement fast entry for syscalls on BOOKE

2019-05-02T15:20:27Z

This patch implements a fast entry for syscalls. Syscalls don't have to preserve non volatile registers except LR. This patch then implement a fast entry for syscalls, where volatile registers get clobbered. As this entry is dedicated to syscall it always sets MSR_EE and warns in case MSR_EE was previously off It also assumes that the call is always from user, system calls are unexpected from kernel. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc/32: get rid of COPY_EE in exception entry

2019-05-02T15:20:27Z

EXC_XFER_TEMPLATE() is not called with COPY_EE anymore so we can get rid of copyee parameters and related COPY_EE and NOCOPY macros. Suggested-by: Benjamin Herrenschmidt [splited out from benh RFC patch] Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc/32: Enter exceptions with MSR_EE unset

2019-05-02T15:20:27Z

All exceptions handlers know when to reenable interrupts, so it is safer to enter all of them with MSR_EE unset, except for syscalls. Suggested-by: Benjamin Herrenschmidt [splited out from benh RFC patch] Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc/32: enter syscall with MSR_EE inconditionaly set

2019-05-02T15:20:27Z

syscalls are expected to be entered with MSR_EE set. Lets make it inconditional by forcing MSR_EE on syscalls. This patch adds EXC_XFER_SYS for that. Suggested-by: Benjamin Herrenschmidt [splited out from benh RFC patch] Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc: Activate CONFIG_THREAD_INFO_IN_TASK

2019-02-23T11:31:40Z

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 Reviewed-by: Nicholas Piggin [mpe: Add task_stack.h to livepatch.h to fix build fails] Signed-off-by: Michael Ellerman

powerpc: Rename THREAD_INFO to TASK_STACK

2019-02-23T11:31:40Z

This patch renames THREAD_INFO to TASK_STACK, because it is in fact the offset of the pointer to the stack in task_struct so this pointer will not be impacted by the move of THREAD_INFO. Also make it available on 64-bit, as we'll need it there when we activate THREAD_INFO_IN_TASK. Signed-off-by: Christophe Leroy Reviewed-by: Nicholas Piggin [mpe: Make available on 64-bit] Signed-off-by: Michael Ellerman

powerpc/fsl: Fixed warning: orphan section `__btb_flush_fixup'

2018-12-30T03:00:47Z

Fixed the following build warning: powerpc-linux-gnu-ld: warning: orphan section `__btb_flush_fixup' from `arch/powerpc/kernel/head_44x.o' being placed in section `__btb_flush_fixup'. Signed-off-by: Diana Craciun Signed-off-by: Michael Ellerman

powerpc/fsl: Flush the branch predictor at each kernel entry (32 bit)

2018-12-20T11:59:03Z

In order to protect against speculation attacks on indirect branches, the branch predictor is flushed at kernel entry to protect for the following situations: - userspace process attacking another userspace process - userspace process attacking the kernel Basically when the privillege level change (i.e.the kernel is entered), the branch predictor state is flushed. Signed-off-by: Diana Craciun Signed-off-by: Michael Ellerman