From: David Brazdil <dbrazdil@google.com>
To: Marc Zyngier <maz@kernel.org>
Cc: kernel-team@android.com, Srinivas Ramana <sramana@codeaurora.org>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-kernel@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org>,
Ajay Patil <pajay@qti.qualcomm.com>,
Prasad Sodagudi <psodagud@codeaurora.org>,
Will Deacon <will@kernel.org>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v4 18/21] arm64: Move "nokaslr" over to the early cpufeature infrastructure
Date: Mon, 18 Jan 2021 14:46:36 +0000 [thread overview]
Message-ID: <20210118144636.kysdvnmcdm7it5zp@google.com> (raw)
In-Reply-To: <20210118094533.2874082-19-maz@kernel.org>
On Mon, Jan 18, 2021 at 09:45:30AM +0000, Marc Zyngier wrote:
> Given that the early cpufeature infrastructure has borrowed quite
> a lot of code from the kaslr implementation, let's reimplement
> the matching of the "nokaslr" option with it.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: David Brazdil <dbrazdil@google.com>
> ---
> arch/arm64/kernel/idreg-override.c | 17 ++++++++++++++
> arch/arm64/kernel/kaslr.c | 37 +++---------------------------
> 2 files changed, 20 insertions(+), 34 deletions(-)
>
> diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c
> index 1db54878b2c4..143fe7b8e3ce 100644
> --- a/arch/arm64/kernel/idreg-override.c
> +++ b/arch/arm64/kernel/idreg-override.c
> @@ -33,8 +33,24 @@ static const struct reg_desc mmfr1 __initdata = {
> },
> };
>
> +extern u64 kaslr_feature_val;
> +extern u64 kaslr_feature_mask;
> +
> +static const struct reg_desc kaslr __initdata = {
> + .name = "kaslr",
> +#ifdef CONFIG_RANDOMIZE_BASE
> + .val = &kaslr_feature_val,
> + .mask = &kaslr_feature_mask,
> +#endif
> + .fields = {
> + { "disabled", 0 },
> + {}
> + },
> +};
> +
> static const struct reg_desc * const regs[] __initdata = {
> &mmfr1,
> + &kaslr,
> };
>
> static const struct {
> @@ -43,6 +59,7 @@ static const struct {
> } aliases[] __initdata = {
> { "kvm-arm.mode=nvhe", "id_aa64mmfr1.vh=0" },
> { "kvm-arm.mode=protected", "id_aa64mmfr1.vh=0" },
> + { "nokaslr", "kaslr.disabled=1" },
> };
>
> static int __init find_field(const char *cmdline, const struct reg_desc *reg,
> diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c
> index 5fc86e7d01a1..dcc4a5aadbe2 100644
> --- a/arch/arm64/kernel/kaslr.c
> +++ b/arch/arm64/kernel/kaslr.c
> @@ -51,39 +51,8 @@ static __init u64 get_kaslr_seed(void *fdt)
> return ret;
> }
>
> -static __init bool cmdline_contains_nokaslr(const u8 *cmdline)
> -{
> - const u8 *str;
> -
> - str = strstr(cmdline, "nokaslr");
> - return str == cmdline || (str > cmdline && *(str - 1) == ' ');
> -}
> -
> -static __init bool is_kaslr_disabled_cmdline(void *fdt)
> -{
> - if (!IS_ENABLED(CONFIG_CMDLINE_FORCE)) {
> - int node;
> - const u8 *prop;
> -
> - node = fdt_path_offset(fdt, "/chosen");
> - if (node < 0)
> - goto out;
> -
> - prop = fdt_getprop(fdt, node, "bootargs", NULL);
> - if (!prop)
> - goto out;
> -
> - if (cmdline_contains_nokaslr(prop))
> - return true;
> -
> - if (IS_ENABLED(CONFIG_CMDLINE_EXTEND))
> - goto out;
> -
> - return false;
> - }
> -out:
> - return cmdline_contains_nokaslr(CONFIG_CMDLINE);
> -}
> +u64 kaslr_feature_val __initdata;
> +u64 kaslr_feature_mask __initdata;
>
> /*
> * This routine will be executed with the kernel mapped at its default virtual
> @@ -126,7 +95,7 @@ u64 __init kaslr_early_init(void)
> * Check if 'nokaslr' appears on the command line, and
> * return 0 if that is the case.
> */
> - if (is_kaslr_disabled_cmdline(fdt)) {
> + if (kaslr_feature_val & kaslr_feature_mask & 0xf) {
nit: Isn't the 0xf redundant here? You don't re-mask for VH either.
> kaslr_status = KASLR_DISABLED_CMDLINE;
> return 0;
> }
> --
> 2.29.2
>
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next prev parent reply other threads:[~2021-01-18 14:46 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-18 9:45 [PATCH v4 00/21] arm64: Early CPU feature override, and applications to VHE, BTI and PAuth Marc Zyngier
2021-01-18 9:45 ` [PATCH v4 01/21] arm64: Fix labels in el2_setup macros Marc Zyngier
2021-01-18 11:13 ` David Brazdil
2021-01-18 9:45 ` [PATCH v4 02/21] arm64: Fix outdated TCR setup comment Marc Zyngier
2021-01-20 18:18 ` Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 03/21] arm64: Turn the MMU-on sequence into a macro Marc Zyngier
2021-01-20 18:18 ` Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 04/21] arm64: Provide an 'upgrade to VHE' stub hypercall Marc Zyngier
2021-01-18 11:25 ` David Brazdil
2021-01-24 18:44 ` Marc Zyngier
2021-01-18 9:45 ` [PATCH v4 05/21] arm64: Initialise as nVHE before switching to VHE Marc Zyngier
2021-01-18 9:45 ` [PATCH v4 06/21] arm64: Move VHE-specific SPE setup to mutate_to_vhe() Marc Zyngier
2021-01-18 9:45 ` [PATCH v4 07/21] arm64: Simplify init_el2_state to be non-VHE only Marc Zyngier
2021-01-18 9:45 ` [PATCH v4 08/21] arm64: Move SCTLR_EL1 initialisation to EL-agnostic code Marc Zyngier
2021-01-20 18:35 ` Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 09/21] arm64: cpufeature: Add global feature override facility Marc Zyngier
2021-01-22 18:41 ` Catalin Marinas
2021-01-23 15:59 ` Suzuki K Poulose
2021-01-18 9:45 ` [PATCH v4 10/21] arm64: cpufeature: Use IDreg override in __read_sysreg_by_encoding() Marc Zyngier
2021-01-22 18:53 ` Catalin Marinas
2021-01-23 16:04 ` Suzuki K Poulose
2021-01-18 9:45 ` [PATCH v4 11/21] arm64: Extract early FDT mapping from kaslr_early_init() Marc Zyngier
2021-01-22 18:55 ` Catalin Marinas
2021-01-23 13:25 ` Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 12/21] arm64: cpufeature: Add an early command-line cpufeature override facility Marc Zyngier
2021-01-18 13:07 ` David Brazdil
2021-01-23 13:23 ` Catalin Marinas
2021-01-23 13:43 ` Catalin Marinas
2021-01-24 16:21 ` Marc Zyngier
2021-01-18 9:45 ` [PATCH v4 13/21] arm64: Allow ID_AA64MMFR1_EL1.VH to be overridden from the command line Marc Zyngier
2021-01-23 14:04 ` Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 14/21] arm64: Honor VHE being disabled from the command-line Marc Zyngier
2021-01-18 13:14 ` David Brazdil
2021-01-23 14:07 ` Catalin Marinas
2021-01-24 15:59 ` Marc Zyngier
2021-01-18 9:45 ` [PATCH v4 15/21] arm64: Add an aliasing facility for the idreg override Marc Zyngier
2021-01-18 13:18 ` David Brazdil
2021-01-24 19:01 ` Marc Zyngier
2021-01-23 14:12 ` Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 16/21] arm64: Make kvm-arm.mode={nvhe, protected} an alias of id_aa64mmfr1.vh=0 Marc Zyngier
2021-01-23 14:15 ` [PATCH v4 16/21] arm64: Make kvm-arm.mode={nvhe,protected} " Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 17/21] KVM: arm64: Document HVC_VHE_RESTART stub hypercall Marc Zyngier
2021-01-18 13:29 ` David Brazdil
2021-01-18 9:45 ` [PATCH v4 18/21] arm64: Move "nokaslr" over to the early cpufeature infrastructure Marc Zyngier
2021-01-18 14:46 ` David Brazdil [this message]
2021-01-24 18:41 ` Marc Zyngier
2021-01-23 14:19 ` Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 19/21] arm64: cpufeatures: Allow disabling of BTI from the command-line Marc Zyngier
2021-01-23 14:24 ` Catalin Marinas
2021-01-26 20:35 ` Srinivas Ramana
2021-01-18 9:45 ` [PATCH v4 20/21] arm64: Defer enabling pointer authentication on boot core Marc Zyngier
2021-01-23 14:26 ` Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 21/21] arm64: cpufeatures: Allow disabling of Pointer Auth from the command-line Marc Zyngier
2021-01-23 14:28 ` Catalin Marinas
2021-01-26 20:30 ` Srinivas Ramana
2021-01-18 14:54 ` [PATCH v4 00/21] arm64: Early CPU feature override, and applications to VHE, BTI and PAuth David Brazdil
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