From: Russell Currey <ruscur@russell.cc> To: linuxppc-dev@lists.ozlabs.org Cc: ajd@linux.ibm.com, kernel-hardening@lists.openwall.com, npiggin@gmail.com, joel@jms.id.au, Russell Currey <ruscur@russell.cc>, dja@axtens.net Subject: [PATCH v6 3/5] powerpc/mm/ptdump: debugfs handler for W+X checks at runtime Date: Tue, 24 Dec 2019 16:55:43 +1100 [thread overview] Message-ID: <20191224055545.178462-4-ruscur@russell.cc> (raw) In-Reply-To: <20191224055545.178462-1-ruscur@russell.cc> Very rudimentary, just echo 1 > [debugfs]/check_wx_pages and check the kernel log. Useful for testing strict module RWX. Updated the Kconfig entry to reflect this. Also fixed a typo. Signed-off-by: Russell Currey <ruscur@russell.cc> --- arch/powerpc/Kconfig.debug | 6 ++++-- arch/powerpc/mm/ptdump/ptdump.c | 21 ++++++++++++++++++++- 2 files changed, 24 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug index 4e1d39847462..7c14c9728bc0 100644 --- a/arch/powerpc/Kconfig.debug +++ b/arch/powerpc/Kconfig.debug @@ -370,7 +370,7 @@ config PPC_PTDUMP If you are unsure, say N. config PPC_DEBUG_WX - bool "Warn on W+X mappings at boot" + bool "Warn on W+X mappings at boot & enable manual checks at runtime" depends on PPC_PTDUMP help Generate a warning if any W+X mappings are found at boot. @@ -384,7 +384,9 @@ config PPC_DEBUG_WX of other unfixed kernel bugs easier. There is no runtime or memory usage effect of this option - once the kernel has booted up - it's a one time check. + once the kernel has booted up, it only automatically checks once. + + Enables the "check_wx_pages" debugfs entry for checking at runtime. If in doubt, say "Y". diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c index 2f9ddc29c535..b6cba29ae4a0 100644 --- a/arch/powerpc/mm/ptdump/ptdump.c +++ b/arch/powerpc/mm/ptdump/ptdump.c @@ -4,7 +4,7 @@ * * This traverses the kernel pagetables and dumps the * information about the used sections of memory to - * /sys/kernel/debug/kernel_pagetables. + * /sys/kernel/debug/kernel_page_tables. * * Derived from the arm64 implementation: * Copyright (c) 2014, The Linux Foundation, Laura Abbott. @@ -409,6 +409,25 @@ void ptdump_check_wx(void) else pr_info("Checked W+X mappings: passed, no W+X pages found\n"); } + +static int check_wx_debugfs_set(void *data, u64 val) +{ + if (val != 1ULL) + return -EINVAL; + + ptdump_check_wx(); + + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(check_wx_fops, NULL, check_wx_debugfs_set, "%llu\n"); + +static int ptdump_check_wx_init(void) +{ + return debugfs_create_file("check_wx_pages", 0200, NULL, + NULL, &check_wx_fops) ? 0 : -ENOMEM; +} +device_initcall(ptdump_check_wx_init); #endif static int ptdump_init(void) -- 2.24.1
WARNING: multiple messages have this Message-ID (diff)
From: Russell Currey <ruscur@russell.cc> To: linuxppc-dev@lists.ozlabs.org Cc: Russell Currey <ruscur@russell.cc>, christophe.leroy@c-s.fr, joel@jms.id.au, mpe@ellerman.id.au, ajd@linux.ibm.com, dja@axtens.net, npiggin@gmail.com, kernel-hardening@lists.openwall.com Subject: [PATCH v6 3/5] powerpc/mm/ptdump: debugfs handler for W+X checks at runtime Date: Tue, 24 Dec 2019 16:55:43 +1100 [thread overview] Message-ID: <20191224055545.178462-4-ruscur@russell.cc> (raw) In-Reply-To: <20191224055545.178462-1-ruscur@russell.cc> Very rudimentary, just echo 1 > [debugfs]/check_wx_pages and check the kernel log. Useful for testing strict module RWX. Updated the Kconfig entry to reflect this. Also fixed a typo. Signed-off-by: Russell Currey <ruscur@russell.cc> --- arch/powerpc/Kconfig.debug | 6 ++++-- arch/powerpc/mm/ptdump/ptdump.c | 21 ++++++++++++++++++++- 2 files changed, 24 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug index 4e1d39847462..7c14c9728bc0 100644 --- a/arch/powerpc/Kconfig.debug +++ b/arch/powerpc/Kconfig.debug @@ -370,7 +370,7 @@ config PPC_PTDUMP If you are unsure, say N. config PPC_DEBUG_WX - bool "Warn on W+X mappings at boot" + bool "Warn on W+X mappings at boot & enable manual checks at runtime" depends on PPC_PTDUMP help Generate a warning if any W+X mappings are found at boot. @@ -384,7 +384,9 @@ config PPC_DEBUG_WX of other unfixed kernel bugs easier. There is no runtime or memory usage effect of this option - once the kernel has booted up - it's a one time check. + once the kernel has booted up, it only automatically checks once. + + Enables the "check_wx_pages" debugfs entry for checking at runtime. If in doubt, say "Y". diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c index 2f9ddc29c535..b6cba29ae4a0 100644 --- a/arch/powerpc/mm/ptdump/ptdump.c +++ b/arch/powerpc/mm/ptdump/ptdump.c @@ -4,7 +4,7 @@ * * This traverses the kernel pagetables and dumps the * information about the used sections of memory to - * /sys/kernel/debug/kernel_pagetables. + * /sys/kernel/debug/kernel_page_tables. * * Derived from the arm64 implementation: * Copyright (c) 2014, The Linux Foundation, Laura Abbott. @@ -409,6 +409,25 @@ void ptdump_check_wx(void) else pr_info("Checked W+X mappings: passed, no W+X pages found\n"); } + +static int check_wx_debugfs_set(void *data, u64 val) +{ + if (val != 1ULL) + return -EINVAL; + + ptdump_check_wx(); + + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(check_wx_fops, NULL, check_wx_debugfs_set, "%llu\n"); + +static int ptdump_check_wx_init(void) +{ + return debugfs_create_file("check_wx_pages", 0200, NULL, + NULL, &check_wx_fops) ? 0 : -ENOMEM; +} +device_initcall(ptdump_check_wx_init); #endif static int ptdump_init(void) -- 2.24.1
next prev parent reply other threads:[~2019-12-24 6:01 UTC|newest] Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-12-24 5:55 [PATCH v6 0/5] Implement STRICT_MODULE_RWX for powerpc Russell Currey 2019-12-24 5:55 ` Russell Currey 2019-12-24 5:55 ` [PATCH v6 1/5] powerpc/mm: Implement set_memory() routines Russell Currey 2019-12-24 5:55 ` Russell Currey 2020-01-08 12:52 ` Christophe Leroy 2020-01-08 12:52 ` Christophe Leroy 2020-02-03 0:46 ` Russell Currey 2020-02-03 0:46 ` Russell Currey 2020-02-03 7:06 ` Christophe Leroy 2020-02-03 7:06 ` Christophe Leroy 2020-01-20 8:35 ` Christophe Leroy 2020-01-20 8:35 ` Christophe Leroy 2019-12-24 5:55 ` [PATCH v6 2/5] powerpc/kprobes: Mark newly allocated probes as RO Russell Currey 2019-12-24 5:55 ` Russell Currey 2020-01-08 16:48 ` Christophe Leroy 2020-01-08 16:48 ` Christophe Leroy 2019-12-24 5:55 ` Russell Currey [this message] 2019-12-24 5:55 ` [PATCH v6 3/5] powerpc/mm/ptdump: debugfs handler for W+X checks at runtime Russell Currey 2019-12-31 17:14 ` Christophe Leroy 2019-12-31 17:14 ` Christophe Leroy 2020-01-07 10:48 ` Michael Ellerman 2020-01-07 10:48 ` Michael Ellerman 2019-12-24 5:55 ` [PATCH v6 4/5] powerpc: Set ARCH_HAS_STRICT_MODULE_RWX Russell Currey 2019-12-24 5:55 ` Russell Currey 2019-12-24 5:55 ` [PATCH v6 5/5] powerpc/configs: Enable STRICT_MODULE_RWX in skiroot_defconfig Russell Currey 2019-12-24 5:55 ` Russell Currey
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