+++ /dev/null
-From 7901783d3ec767ec9071be56943ced4ec4ad8d7f Mon Sep 17 00:00:00 2001
-From: Sasha Levin <sashal@kernel.org>
-Date: Sun, 23 Jan 2022 20:18:33 +0100
-Subject: ARM: ftrace: avoid redundant loads or clobbering IP
-
-From: Ard Biesheuvel <ardb@kernel.org>
-
-[ Upstream commit d11967870815b5ab89843980e35aab616c97c463 ]
-
-Tweak the ftrace return paths to avoid redundant loads of SP, as well as
-unnecessary clobbering of IP.
-
-This also fixes the inconsistency of using MOV to perform a function
-return, which is sub-optimal on recent micro-architectures but more
-importantly, does not perform an interworking return, unlike compiler
-generated function returns in Thumb2 builds.
-
-Let's fix this by popping PC from the stack like most ordinary code
-does.
-
-Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
-Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-Signed-off-by: Sasha Levin <sashal@kernel.org>
----
- arch/arm/kernel/entry-ftrace.S | 51 +++++++++++++++-------------------
- 1 file changed, 22 insertions(+), 29 deletions(-)
-
-diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S
-index 1acf4d05e94c..393c342ecd51 100644
---- a/arch/arm/kernel/entry-ftrace.S
-+++ b/arch/arm/kernel/entry-ftrace.S
-@@ -41,10 +41,7 @@
- * mcount can be thought of as a function called in the middle of a subroutine
- * call. As such, it needs to be transparent for both the caller and the
- * callee: the original lr needs to be restored when leaving mcount, and no
-- * registers should be clobbered. (In the __gnu_mcount_nc implementation, we
-- * clobber the ip register. This is OK because the ARM calling convention
-- * allows it to be clobbered in subroutines and doesn't use it to hold
-- * parameters.)
-+ * registers should be clobbered.
- *
- * When using dynamic ftrace, we patch out the mcount call by a "mov r0, r0"
- * for the mcount case, and a "pop {lr}" for the __gnu_mcount_nc case (see
-@@ -96,26 +93,25 @@
-
- .macro __ftrace_regs_caller
-
-- sub sp, sp, #8 @ space for PC and CPSR OLD_R0,
-+ str lr, [sp, #-8]! @ store LR as PC and make space for CPSR/OLD_R0,
- @ OLD_R0 will overwrite previous LR
-
-- add ip, sp, #12 @ move in IP the value of SP as it was
-- @ before the push {lr} of the mcount mechanism
-+ ldr lr, [sp, #8] @ get previous LR
-
-- str lr, [sp, #0] @ store LR instead of PC
-+ str r0, [sp, #8] @ write r0 as OLD_R0 over previous LR
-
-- ldr lr, [sp, #8] @ get previous LR
-+ str lr, [sp, #-4]! @ store previous LR as LR
-
-- str r0, [sp, #8] @ write r0 as OLD_R0 over previous LR
-+ add lr, sp, #16 @ move in LR the value of SP as it was
-+ @ before the push {lr} of the mcount mechanism
-
-- stmdb sp!, {ip, lr}
-- stmdb sp!, {r0-r11, lr}
-+ push {r0-r11, ip, lr}
-
- @ stack content at this point:
- @ 0 4 48 52 56 60 64 68 72
-- @ R0 | R1 | ... | LR | SP + 4 | previous LR | LR | PSR | OLD_R0 |
-+ @ R0 | R1 | ... | IP | SP + 4 | previous LR | LR | PSR | OLD_R0 |
-
-- mov r3, sp @ struct pt_regs*
-+ mov r3, sp @ struct pt_regs*
-
- ldr r2, =function_trace_op
- ldr r2, [r2] @ pointer to the current
-@@ -138,11 +134,9 @@ ftrace_graph_regs_call:
- #endif
-
- @ pop saved regs
-- ldmia sp!, {r0-r12} @ restore r0 through r12
-- ldr ip, [sp, #8] @ restore PC
-- ldr lr, [sp, #4] @ restore LR
-- ldr sp, [sp, #0] @ restore SP
-- mov pc, ip @ return
-+ pop {r0-r11, ip, lr} @ restore r0 through r12
-+ ldr lr, [sp], #4 @ restore LR
-+ ldr pc, [sp], #12
- .endm
-
- #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-@@ -158,11 +152,9 @@ ftrace_graph_regs_call:
- bl prepare_ftrace_return
-
- @ pop registers saved in ftrace_regs_caller
-- ldmia sp!, {r0-r12} @ restore r0 through r12
-- ldr ip, [sp, #8] @ restore PC
-- ldr lr, [sp, #4] @ restore LR
-- ldr sp, [sp, #0] @ restore SP
-- mov pc, ip @ return
-+ pop {r0-r11, ip, lr} @ restore r0 through r12
-+ ldr lr, [sp], #4 @ restore LR
-+ ldr pc, [sp], #12
-
- .endm
- #endif
-@@ -273,16 +265,17 @@ ENDPROC(ftrace_graph_caller_old)
- .endm
-
- .macro mcount_exit
-- ldmia sp!, {r0-r3, ip, lr}
-- ret ip
-+ ldmia sp!, {r0-r3}
-+ ldr lr, [sp, #4]
-+ ldr pc, [sp], #8
- .endm
-
- ENTRY(__gnu_mcount_nc)
- UNWIND(.fnstart)
- #ifdef CONFIG_DYNAMIC_FTRACE
-- mov ip, lr
-- ldmia sp!, {lr}
-- ret ip
-+ push {lr}
-+ ldr lr, [sp, #4]
-+ ldr pc, [sp], #8
- #else
- __mcount
- #endif
---
-2.34.1
-
video-fbdev-omapfb-acx565akm-replace-snprintf-with-s.patch
arm-dts-qcom-fix-gic_irq_domain_translate-warnings-f.patch
arm-dts-bcm2837-add-the-missing-l1-l2-cache-informat.patch
-arm-ftrace-avoid-redundant-loads-or-clobbering-ip.patch
video-fbdev-omapfb-panel-dsi-cm-use-sysfs_emit-inste.patch
video-fbdev-omapfb-panel-tpo-td043mtea1-use-sysfs_em.patch
asoc-soc-core-skip-zero-num_dai-component-in-searchi.patch
+++ /dev/null
-From 84e5759501033fb4384127dd40f02f935be104d4 Mon Sep 17 00:00:00 2001
-From: Sasha Levin <sashal@kernel.org>
-Date: Sun, 23 Jan 2022 20:18:33 +0100
-Subject: ARM: ftrace: avoid redundant loads or clobbering IP
-
-From: Ard Biesheuvel <ardb@kernel.org>
-
-[ Upstream commit d11967870815b5ab89843980e35aab616c97c463 ]
-
-Tweak the ftrace return paths to avoid redundant loads of SP, as well as
-unnecessary clobbering of IP.
-
-This also fixes the inconsistency of using MOV to perform a function
-return, which is sub-optimal on recent micro-architectures but more
-importantly, does not perform an interworking return, unlike compiler
-generated function returns in Thumb2 builds.
-
-Let's fix this by popping PC from the stack like most ordinary code
-does.
-
-Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
-Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-Signed-off-by: Sasha Levin <sashal@kernel.org>
----
- arch/arm/kernel/entry-ftrace.S | 51 +++++++++++++++-------------------
- 1 file changed, 22 insertions(+), 29 deletions(-)
-
-diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S
-index 1acf4d05e94c..393c342ecd51 100644
---- a/arch/arm/kernel/entry-ftrace.S
-+++ b/arch/arm/kernel/entry-ftrace.S
-@@ -41,10 +41,7 @@
- * mcount can be thought of as a function called in the middle of a subroutine
- * call. As such, it needs to be transparent for both the caller and the
- * callee: the original lr needs to be restored when leaving mcount, and no
-- * registers should be clobbered. (In the __gnu_mcount_nc implementation, we
-- * clobber the ip register. This is OK because the ARM calling convention
-- * allows it to be clobbered in subroutines and doesn't use it to hold
-- * parameters.)
-+ * registers should be clobbered.
- *
- * When using dynamic ftrace, we patch out the mcount call by a "mov r0, r0"
- * for the mcount case, and a "pop {lr}" for the __gnu_mcount_nc case (see
-@@ -96,26 +93,25 @@
-
- .macro __ftrace_regs_caller
-
-- sub sp, sp, #8 @ space for PC and CPSR OLD_R0,
-+ str lr, [sp, #-8]! @ store LR as PC and make space for CPSR/OLD_R0,
- @ OLD_R0 will overwrite previous LR
-
-- add ip, sp, #12 @ move in IP the value of SP as it was
-- @ before the push {lr} of the mcount mechanism
-+ ldr lr, [sp, #8] @ get previous LR
-
-- str lr, [sp, #0] @ store LR instead of PC
-+ str r0, [sp, #8] @ write r0 as OLD_R0 over previous LR
-
-- ldr lr, [sp, #8] @ get previous LR
-+ str lr, [sp, #-4]! @ store previous LR as LR
-
-- str r0, [sp, #8] @ write r0 as OLD_R0 over previous LR
-+ add lr, sp, #16 @ move in LR the value of SP as it was
-+ @ before the push {lr} of the mcount mechanism
-
-- stmdb sp!, {ip, lr}
-- stmdb sp!, {r0-r11, lr}
-+ push {r0-r11, ip, lr}
-
- @ stack content at this point:
- @ 0 4 48 52 56 60 64 68 72
-- @ R0 | R1 | ... | LR | SP + 4 | previous LR | LR | PSR | OLD_R0 |
-+ @ R0 | R1 | ... | IP | SP + 4 | previous LR | LR | PSR | OLD_R0 |
-
-- mov r3, sp @ struct pt_regs*
-+ mov r3, sp @ struct pt_regs*
-
- ldr r2, =function_trace_op
- ldr r2, [r2] @ pointer to the current
-@@ -138,11 +134,9 @@ ftrace_graph_regs_call:
- #endif
-
- @ pop saved regs
-- ldmia sp!, {r0-r12} @ restore r0 through r12
-- ldr ip, [sp, #8] @ restore PC
-- ldr lr, [sp, #4] @ restore LR
-- ldr sp, [sp, #0] @ restore SP
-- mov pc, ip @ return
-+ pop {r0-r11, ip, lr} @ restore r0 through r12
-+ ldr lr, [sp], #4 @ restore LR
-+ ldr pc, [sp], #12
- .endm
-
- #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-@@ -158,11 +152,9 @@ ftrace_graph_regs_call:
- bl prepare_ftrace_return
-
- @ pop registers saved in ftrace_regs_caller
-- ldmia sp!, {r0-r12} @ restore r0 through r12
-- ldr ip, [sp, #8] @ restore PC
-- ldr lr, [sp, #4] @ restore LR
-- ldr sp, [sp, #0] @ restore SP
-- mov pc, ip @ return
-+ pop {r0-r11, ip, lr} @ restore r0 through r12
-+ ldr lr, [sp], #4 @ restore LR
-+ ldr pc, [sp], #12
-
- .endm
- #endif
-@@ -273,16 +265,17 @@ ENDPROC(ftrace_graph_caller_old)
- .endm
-
- .macro mcount_exit
-- ldmia sp!, {r0-r3, ip, lr}
-- ret ip
-+ ldmia sp!, {r0-r3}
-+ ldr lr, [sp, #4]
-+ ldr pc, [sp], #8
- .endm
-
- ENTRY(__gnu_mcount_nc)
- UNWIND(.fnstart)
- #ifdef CONFIG_DYNAMIC_FTRACE
-- mov ip, lr
-- ldmia sp!, {lr}
-- ret ip
-+ push {lr}
-+ ldr lr, [sp, #4]
-+ ldr pc, [sp], #8
- #else
- __mcount
- #endif
---
-2.34.1
-
video-fbdev-omapfb-acx565akm-replace-snprintf-with-s.patch
arm-dts-qcom-fix-gic_irq_domain_translate-warnings-f.patch
arm-dts-bcm2837-add-the-missing-l1-l2-cache-informat.patch
-arm-ftrace-avoid-redundant-loads-or-clobbering-ip.patch
video-fbdev-omapfb-panel-dsi-cm-use-sysfs_emit-inste.patch
video-fbdev-omapfb-panel-tpo-td043mtea1-use-sysfs_em.patch
video-fbdev-udlfb-replace-snprintf-in-show-functions.patch
+++ /dev/null
-From db35b8053101f689e113a794dcb40e8476f2e6a2 Mon Sep 17 00:00:00 2001
-From: Sasha Levin <sashal@kernel.org>
-Date: Sun, 23 Jan 2022 20:18:33 +0100
-Subject: ARM: ftrace: avoid redundant loads or clobbering IP
-
-From: Ard Biesheuvel <ardb@kernel.org>
-
-[ Upstream commit d11967870815b5ab89843980e35aab616c97c463 ]
-
-Tweak the ftrace return paths to avoid redundant loads of SP, as well as
-unnecessary clobbering of IP.
-
-This also fixes the inconsistency of using MOV to perform a function
-return, which is sub-optimal on recent micro-architectures but more
-importantly, does not perform an interworking return, unlike compiler
-generated function returns in Thumb2 builds.
-
-Let's fix this by popping PC from the stack like most ordinary code
-does.
-
-Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
-Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-Signed-off-by: Sasha Levin <sashal@kernel.org>
----
- arch/arm/kernel/entry-ftrace.S | 51 +++++++++++++++-------------------
- 1 file changed, 22 insertions(+), 29 deletions(-)
-
-diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S
-index f4886fb6e9ba..f33c171e3090 100644
---- a/arch/arm/kernel/entry-ftrace.S
-+++ b/arch/arm/kernel/entry-ftrace.S
-@@ -22,10 +22,7 @@
- * mcount can be thought of as a function called in the middle of a subroutine
- * call. As such, it needs to be transparent for both the caller and the
- * callee: the original lr needs to be restored when leaving mcount, and no
-- * registers should be clobbered. (In the __gnu_mcount_nc implementation, we
-- * clobber the ip register. This is OK because the ARM calling convention
-- * allows it to be clobbered in subroutines and doesn't use it to hold
-- * parameters.)
-+ * registers should be clobbered.
- *
- * When using dynamic ftrace, we patch out the mcount call by a "pop {lr}"
- * instead of the __gnu_mcount_nc call (see arch/arm/kernel/ftrace.c).
-@@ -70,26 +67,25 @@
-
- .macro __ftrace_regs_caller
-
-- sub sp, sp, #8 @ space for PC and CPSR OLD_R0,
-+ str lr, [sp, #-8]! @ store LR as PC and make space for CPSR/OLD_R0,
- @ OLD_R0 will overwrite previous LR
-
-- add ip, sp, #12 @ move in IP the value of SP as it was
-- @ before the push {lr} of the mcount mechanism
-+ ldr lr, [sp, #8] @ get previous LR
-
-- str lr, [sp, #0] @ store LR instead of PC
-+ str r0, [sp, #8] @ write r0 as OLD_R0 over previous LR
-
-- ldr lr, [sp, #8] @ get previous LR
-+ str lr, [sp, #-4]! @ store previous LR as LR
-
-- str r0, [sp, #8] @ write r0 as OLD_R0 over previous LR
-+ add lr, sp, #16 @ move in LR the value of SP as it was
-+ @ before the push {lr} of the mcount mechanism
-
-- stmdb sp!, {ip, lr}
-- stmdb sp!, {r0-r11, lr}
-+ push {r0-r11, ip, lr}
-
- @ stack content at this point:
- @ 0 4 48 52 56 60 64 68 72
-- @ R0 | R1 | ... | LR | SP + 4 | previous LR | LR | PSR | OLD_R0 |
-+ @ R0 | R1 | ... | IP | SP + 4 | previous LR | LR | PSR | OLD_R0 |
-
-- mov r3, sp @ struct pt_regs*
-+ mov r3, sp @ struct pt_regs*
-
- ldr r2, =function_trace_op
- ldr r2, [r2] @ pointer to the current
-@@ -112,11 +108,9 @@ ftrace_graph_regs_call:
- #endif
-
- @ pop saved regs
-- ldmia sp!, {r0-r12} @ restore r0 through r12
-- ldr ip, [sp, #8] @ restore PC
-- ldr lr, [sp, #4] @ restore LR
-- ldr sp, [sp, #0] @ restore SP
-- mov pc, ip @ return
-+ pop {r0-r11, ip, lr} @ restore r0 through r12
-+ ldr lr, [sp], #4 @ restore LR
-+ ldr pc, [sp], #12
- .endm
-
- #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-@@ -132,11 +126,9 @@ ftrace_graph_regs_call:
- bl prepare_ftrace_return
-
- @ pop registers saved in ftrace_regs_caller
-- ldmia sp!, {r0-r12} @ restore r0 through r12
-- ldr ip, [sp, #8] @ restore PC
-- ldr lr, [sp, #4] @ restore LR
-- ldr sp, [sp, #0] @ restore SP
-- mov pc, ip @ return
-+ pop {r0-r11, ip, lr} @ restore r0 through r12
-+ ldr lr, [sp], #4 @ restore LR
-+ ldr pc, [sp], #12
-
- .endm
- #endif
-@@ -202,16 +194,17 @@ ftrace_graph_call\suffix:
- .endm
-
- .macro mcount_exit
-- ldmia sp!, {r0-r3, ip, lr}
-- ret ip
-+ ldmia sp!, {r0-r3}
-+ ldr lr, [sp, #4]
-+ ldr pc, [sp], #8
- .endm
-
- ENTRY(__gnu_mcount_nc)
- UNWIND(.fnstart)
- #ifdef CONFIG_DYNAMIC_FTRACE
-- mov ip, lr
-- ldmia sp!, {lr}
-- ret ip
-+ push {lr}
-+ ldr lr, [sp, #4]
-+ ldr pc, [sp], #8
- #else
- __mcount
- #endif
---
-2.34.1
-
arm-dts-qcom-fix-gic_irq_domain_translate-warnings-f.patch
arm-dts-bcm2837-add-the-missing-l1-l2-cache-informat.patch
asoc-madera-add-dependencies-on-mfd.patch
-arm-ftrace-avoid-redundant-loads-or-clobbering-ip.patch
video-fbdev-omapfb-panel-dsi-cm-use-sysfs_emit-inste.patch
video-fbdev-omapfb-panel-tpo-td043mtea1-use-sysfs_em.patch
video-fbdev-udlfb-replace-snprintf-in-show-functions.patch
projects / thirdparty / kernel / stable-queue.git / commitdiff
