From d920eaa4c4559f59be7b4c2d26fa0a2e1aaa3da9 Mon Sep 17 00:00:00 2001 From: "Russell King (Oracle)" Date: Wed, 16 Feb 2022 15:37:38 +0000 Subject: [PATCH 1/3] ARM: Fix kgdb breakpoint for Thumb2 The kgdb code needs to register an undef hook for the Thumb UDF instruction that will fault in order to be functional on Thumb2 platforms. Reported-by: Johannes Stezenbach Tested-by: Johannes Stezenbach Fixes: 5cbad0ebf45c ("kgdb: support for ARCH=arm") Signed-off-by: Russell King (Oracle) --- arch/arm/kernel/kgdb.c | 36 ++++++++++++++++++++++++++++-------- 1 file changed, 28 insertions(+), 8 deletions(-) diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c index 7bd30c0a4280..22f937e6f3ff 100644 --- a/arch/arm/kernel/kgdb.c +++ b/arch/arm/kernel/kgdb.c @@ -154,22 +154,38 @@ static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr) return 0; } -static struct undef_hook kgdb_brkpt_hook = { +static struct undef_hook kgdb_brkpt_arm_hook = { .instr_mask = 0xffffffff, .instr_val = KGDB_BREAKINST, - .cpsr_mask = MODE_MASK, + .cpsr_mask = PSR_T_BIT | MODE_MASK, .cpsr_val = SVC_MODE, .fn = kgdb_brk_fn }; -static struct undef_hook kgdb_compiled_brkpt_hook = { +static struct undef_hook kgdb_brkpt_thumb_hook = { + .instr_mask = 0xffff, + .instr_val = KGDB_BREAKINST & 0xffff, + .cpsr_mask = PSR_T_BIT | MODE_MASK, + .cpsr_val = PSR_T_BIT | SVC_MODE, + .fn = kgdb_brk_fn +}; + +static struct undef_hook kgdb_compiled_brkpt_arm_hook = { .instr_mask = 0xffffffff, .instr_val = KGDB_COMPILED_BREAK, - .cpsr_mask = MODE_MASK, + .cpsr_mask = PSR_T_BIT | MODE_MASK, .cpsr_val = SVC_MODE, .fn = kgdb_compiled_brk_fn }; +static struct undef_hook kgdb_compiled_brkpt_thumb_hook = { + .instr_mask = 0xffff, + .instr_val = KGDB_COMPILED_BREAK & 0xffff, + .cpsr_mask = PSR_T_BIT | MODE_MASK, + .cpsr_val = PSR_T_BIT | SVC_MODE, + .fn = kgdb_compiled_brk_fn +}; + static int __kgdb_notify(struct die_args *args, unsigned long cmd) { struct pt_regs *regs = args->regs; @@ -210,8 +226,10 @@ int kgdb_arch_init(void) if (ret != 0) return ret; - register_undef_hook(&kgdb_brkpt_hook); - register_undef_hook(&kgdb_compiled_brkpt_hook); + register_undef_hook(&kgdb_brkpt_arm_hook); + register_undef_hook(&kgdb_brkpt_thumb_hook); + register_undef_hook(&kgdb_compiled_brkpt_arm_hook); + register_undef_hook(&kgdb_compiled_brkpt_thumb_hook); return 0; } @@ -224,8 +242,10 @@ int kgdb_arch_init(void) */ void kgdb_arch_exit(void) { - unregister_undef_hook(&kgdb_brkpt_hook); - unregister_undef_hook(&kgdb_compiled_brkpt_hook); + unregister_undef_hook(&kgdb_brkpt_arm_hook); + unregister_undef_hook(&kgdb_brkpt_thumb_hook); + unregister_undef_hook(&kgdb_compiled_brkpt_arm_hook); + unregister_undef_hook(&kgdb_compiled_brkpt_thumb_hook); unregister_die_notifier(&kgdb_notifier); } From 11c57c3ba94da74c3446924260e34e0b1950b5d7 Mon Sep 17 00:00:00 2001 From: Julian Braha Date: Mon, 17 Jan 2022 05:09:40 +0100 Subject: [PATCH 2/3] ARM: 9178/1: fix unmet dependency on BITREVERSE for HAVE_ARCH_BITREVERSE Resending this to properly add it to the patch tracker - thanks for letting me know, Arnd :) When ARM is enabled, and BITREVERSE is disabled, Kbuild gives the following warning: WARNING: unmet direct dependencies detected for HAVE_ARCH_BITREVERSE Depends on [n]: BITREVERSE [=n] Selected by [y]: - ARM [=y] && (CPU_32v7M [=n] || CPU_32v7 [=y]) && !CPU_32v6 [=n] This is because ARM selects HAVE_ARCH_BITREVERSE without selecting BITREVERSE, despite HAVE_ARCH_BITREVERSE depending on BITREVERSE. This unmet dependency bug was found by Kismet, a static analysis tool for Kconfig. Please advise if this is not the appropriate solution. Signed-off-by: Julian Braha Signed-off-by: Russell King (Oracle) --- lib/Kconfig | 1 - 1 file changed, 1 deletion(-) diff --git a/lib/Kconfig b/lib/Kconfig index 5e7165e6a346..fa4b10322efc 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -45,7 +45,6 @@ config BITREVERSE config HAVE_ARCH_BITREVERSE bool default n - depends on BITREVERSE help This option enables the use of hardware bit-reversal instructions on architectures which support such operations. From 7b83299e5b9385943a857d59e15cba270df20d7e Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Wed, 23 Feb 2022 20:46:35 +0100 Subject: [PATCH 3/3] ARM: 9182/1: mmu: fix returns from early_param() and __setup() functions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit early_param() handlers should return 0 on success. __setup() handlers should return 1 on success, i.e., the parameter has been handled. A return of 0 would cause the "option=value" string to be added to init's environment strings, polluting it. ../arch/arm/mm/mmu.c: In function 'test_early_cachepolicy': ../arch/arm/mm/mmu.c:215:1: error: no return statement in function returning non-void [-Werror=return-type] ../arch/arm/mm/mmu.c: In function 'test_noalign_setup': ../arch/arm/mm/mmu.c:221:1: error: no return statement in function returning non-void [-Werror=return-type] Fixes: b849a60e0903 ("ARM: make cr_alignment read-only #ifndef CONFIG_CPU_CP15") Signed-off-by: Randy Dunlap Reported-by: Igor Zhbanov Cc: Uwe Kleine-König Cc: linux-arm-kernel@lists.infradead.org Cc: patches@armlinux.org.uk Signed-off-by: Russell King (Oracle) --- arch/arm/mm/mmu.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 274e4f73fd33..5e2be37a198e 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -212,12 +212,14 @@ early_param("ecc", early_ecc); static int __init early_cachepolicy(char *p) { pr_warn("cachepolicy kernel parameter not supported without cp15\n"); + return 0; } early_param("cachepolicy", early_cachepolicy); static int __init noalign_setup(char *__unused) { pr_warn("noalign kernel parameter not supported without cp15\n"); + return 1; } __setup("noalign", noalign_setup);