Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

Pull ARM updates from Russell King:
 "Updates for IRQ stacks and virtually mapped stack support, and ftrace:

   - Support for IRQ and vmap'ed stacks

     This covers all the work related to implementing IRQ stacks and
     vmap'ed stacks for all 32-bit ARM systems that are currently
     supported by the Linux kernel, including RiscPC and Footbridge. It
     has been submitted for review in four different waves:

      - IRQ stacks support for v7 SMP systems [0]

      - vmap'ed stacks support for v7 SMP systems[1]

      - extending support for both IRQ stacks and vmap'ed stacks for all
        remaining configurations, including v6/v7 SMP multiplatform
        kernels and uniprocessor configurations including v7-M [2]

      - fixes and updates in [3]

   - ftrace fixes and cleanups

     Make all flavors of ftrace available on all builds, regardless of
     ISA choice, unwinder choice or compiler [4]:

      - use ADD not POP where possible

      - fix a couple of Thumb2 related issues

      - enable HAVE_FUNCTION_GRAPH_FP_TEST for robustness

      - enable the graph tracer with the EABI unwinder

      - avoid clobbering frame pointer registers to make Clang happy

   - Fixes for the above"

[0] https://lore.kernel.org/linux-arm-kernel/20211115084732.3704393-1-ardb@kernel.org/
[1] https://lore.kernel.org/linux-arm-kernel/20211122092816.2865873-1-ardb@kernel.org/
[2] https://lore.kernel.org/linux-arm-kernel/20211206164659.1495084-1-ardb@kernel.org/
[3] https://lore.kernel.org/linux-arm-kernel/20220124174744.1054712-1-ardb@kernel.org/
[4] https://lore.kernel.org/linux-arm-kernel/20220203082204.1176734-1-ardb@kernel.org/

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (62 commits)
  ARM: fix building NOMMU ARMv4/v5 kernels
  ARM: unwind: only permit stack switch when unwinding call_with_stack()
  ARM: Revert "unwind: dump exception stack from calling frame"
  ARM: entry: fix unwinder problems caused by IRQ stacks
  ARM: unwind: set frame.pc correctly for current-thread unwinding
  ARM: 9184/1: return_address: disable again for CONFIG_ARM_UNWIND=y
  ARM: 9183/1: unwind: avoid spurious warnings on bogus code addresses
  Revert "ARM: 9144/1: forbid ftrace with clang and thumb2_kernel"
  ARM: mach-bcm: disable ftrace in SMC invocation routines
  ARM: cacheflush: avoid clobbering the frame pointer
  ARM: kprobes: treat R7 as the frame pointer register in Thumb2 builds
  ARM: ftrace: enable the graph tracer with the EABI unwinder
  ARM: unwind: track location of LR value in stack frame
  ARM: ftrace: enable HAVE_FUNCTION_GRAPH_FP_TEST
  ARM: ftrace: avoid unnecessary literal loads
  ARM: ftrace: avoid redundant loads or clobbering IP
  ARM: ftrace: use trampolines to keep .init.text in branching range
  ARM: ftrace: use ADD not POP to counter PUSH at entry
  ARM: ftrace: ensure that ADR takes the Thumb bit into account
  ARM: make get_current() and __my_cpu_offset() __always_inline
  ...

2 files changed, 17 insertions, 7 deletions

diff --git a/arch/arm/probes/kprobes/actions-common.c b/arch/arm/probes/kprobes/actions-common.c
index 836aebe596cd..79171344dbeb 100644
--- a/arch/arm/probes/kprobes/actions-common.c
+++ b/arch/arm/probes/kprobes/actions-common.c
@@ -84,7 +84,8 @@ emulate_generic_r0_12_noflags(probes_opcode_t insn,
 	register void *rfn asm("lr") = asi->insn_fn;
 
 	__asm__ __volatile__ (
-		"stmdb	sp!, {%[regs], r11}	\n\t"
+ARM(		"stmdb	sp!, {%[regs], r11}	\n\t"	)
+THUMB(		"stmdb	sp!, {%[regs], r7}	\n\t"	)
 		"ldmia	%[regs], {r0-r12}	\n\t"
 #if __LINUX_ARM_ARCH__ >= 6
 		"blx	%[fn]			\n\t"
@@ -96,10 +97,11 @@ emulate_generic_r0_12_noflags(probes_opcode_t insn,
 #endif
 		"ldr	lr, [sp], #4		\n\t" /* lr = regs */
 		"stmia	lr, {r0-r12}		\n\t"
-		"ldr	r11, [sp], #4		\n\t"
+ARM(		"ldr	r11, [sp], #4		\n\t"	)
+THUMB(		"ldr	r7, [sp], #4		\n\t"	)
 		: [regs] "=r" (rregs), [fn] "=r" (rfn)
 		: "0" (rregs), "1" (rfn)
-		: "r0", "r2", "r3", "r4", "r5", "r6", "r7",
+		: "r0", "r2", "r3", "r4", "r5", "r6", ARM("r7") THUMB("r11"),
 		  "r8", "r9", "r10", "r12", "memory", "cc"
 		);
 }
diff --git a/arch/arm/probes/kprobes/actions-thumb.c b/arch/arm/probes/kprobes/actions-thumb.c
index 7884fcb81c26..51624fc263fc 100644
--- a/arch/arm/probes/kprobes/actions-thumb.c
+++ b/arch/arm/probes/kprobes/actions-thumb.c
@@ -447,14 +447,16 @@ t16_emulate_loregs(probes_opcode_t insn,
 
 	__asm__ __volatile__ (
 		"msr	cpsr_fs, %[oldcpsr]	\n\t"
+		"mov	r11, r7			\n\t"
 		"ldmia	%[regs], {r0-r7}	\n\t"
 		"blx	%[fn]			\n\t"
 		"stmia	%[regs], {r0-r7}	\n\t"
+		"mov	r7, r11			\n\t"
 		"mrs	%[newcpsr], cpsr	\n\t"
 		: [newcpsr] "=r" (newcpsr)
 		: [oldcpsr] "r" (oldcpsr), [regs] "r" (regs),
 		  [fn] "r" (asi->insn_fn)
-		: "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
+		: "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r11",
 		  "lr", "memory", "cc"
 		);
 
@@ -524,14 +526,16 @@ t16_emulate_push(probes_opcode_t insn,
 		struct arch_probes_insn *asi, struct pt_regs *regs)
 {
 	__asm__ __volatile__ (
+		"mov	r11, r7			\n\t"
 		"ldr	r9, [%[regs], #13*4]	\n\t"
 		"ldr	r8, [%[regs], #14*4]	\n\t"
 		"ldmia	%[regs], {r0-r7}	\n\t"
 		"blx	%[fn]			\n\t"
 		"str	r9, [%[regs], #13*4]	\n\t"
+		"mov	r7, r11			\n\t"
 		:
 		: [regs] "r" (regs), [fn] "r" (asi->insn_fn)
-		: "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9",
+		: "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r8", "r9", "r11",
 		  "lr", "memory", "cc"
 		);
 }
@@ -558,14 +562,16 @@ t16_emulate_pop_nopc(probes_opcode_t insn,
 		struct arch_probes_insn *asi, struct pt_regs *regs)
 {
 	__asm__ __volatile__ (
+		"mov	r11, r7			\n\t"
 		"ldr	r9, [%[regs], #13*4]	\n\t"
 		"ldmia	%[regs], {r0-r7}	\n\t"
 		"blx	%[fn]			\n\t"
 		"stmia	%[regs], {r0-r7}	\n\t"
 		"str	r9, [%[regs], #13*4]	\n\t"
+		"mov	r7, r11			\n\t"
 		:
 		: [regs] "r" (regs), [fn] "r" (asi->insn_fn)
-		: "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r9",
+		: "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r9", "r11",
 		  "lr", "memory", "cc"
 		);
 }
@@ -577,14 +583,16 @@ t16_emulate_pop_pc(probes_opcode_t insn,
 	register unsigned long pc asm("r8");
 
 	__asm__ __volatile__ (
+		"mov	r11, r7			\n\t"
 		"ldr	r9, [%[regs], #13*4]	\n\t"
 		"ldmia	%[regs], {r0-r7}	\n\t"
 		"blx	%[fn]			\n\t"
 		"stmia	%[regs], {r0-r7}	\n\t"
 		"str	r9, [%[regs], #13*4]	\n\t"
+		"mov	r7, r11			\n\t"
 		: "=r" (pc)
 		: [regs] "r" (regs), [fn] "r" (asi->insn_fn)
-		: "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r9",
+		: "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r9", "r11",
 		  "lr", "memory", "cc"
 		);