From: Ard Biesheuvel <ardb@kernel.org> To: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com, linux-efi@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org> Subject: [PATCH 1/2] efi/libstub/arm64: avoid copying the kernel unnecessarily Date: Thu, 26 Mar 2020 17:59:04 +0100 [thread overview] Message-ID: <20200326165905.2240-2-ardb@kernel.org> (raw) In-Reply-To: <20200326165905.2240-1-ardb@kernel.org> If the UEFI firmware has loaded the kernel at the right alignment, and we are running a relocatable kernel, there is no point in copying the kernel to a different place in memory, and instead, we can just run it in place. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- drivers/firmware/efi/libstub/arm64-stub.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c index 9254cd8ab2d3..d263f504dcf0 100644 --- a/drivers/firmware/efi/libstub/arm64-stub.c +++ b/drivers/firmware/efi/libstub/arm64-stub.c @@ -104,6 +104,15 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, (u32)phys_seed); *image_addr = *reserve_addr + offset; + } else if (IS_ENABLED(CONFIG_RELOCATABLE) && + IS_ALIGNED((u64)_text - TEXT_OFFSET, EFI_KIMG_ALIGN)) { + /* + * If we are relocatable and were loaded at a suitable offset, + * there is no need to do anything and we can just execute in + * place. + */ + *image_addr = (u64)_text; + return EFI_SUCCESS; } else { /* * Else, try a straight allocation at the preferred offset. -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: Ard Biesheuvel <ardb@kernel.org> To: linux-arm-kernel@lists.infradead.org Cc: mark.rutland@arm.com, catalin.marinas@arm.com, linux-efi@vger.kernel.org, will@kernel.org, Ard Biesheuvel <ardb@kernel.org> Subject: [PATCH 1/2] efi/libstub/arm64: avoid copying the kernel unnecessarily Date: Thu, 26 Mar 2020 17:59:04 +0100 [thread overview] Message-ID: <20200326165905.2240-2-ardb@kernel.org> (raw) In-Reply-To: <20200326165905.2240-1-ardb@kernel.org> If the UEFI firmware has loaded the kernel at the right alignment, and we are running a relocatable kernel, there is no point in copying the kernel to a different place in memory, and instead, we can just run it in place. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- drivers/firmware/efi/libstub/arm64-stub.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c index 9254cd8ab2d3..d263f504dcf0 100644 --- a/drivers/firmware/efi/libstub/arm64-stub.c +++ b/drivers/firmware/efi/libstub/arm64-stub.c @@ -104,6 +104,15 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, (u32)phys_seed); *image_addr = *reserve_addr + offset; + } else if (IS_ENABLED(CONFIG_RELOCATABLE) && + IS_ALIGNED((u64)_text - TEXT_OFFSET, EFI_KIMG_ALIGN)) { + /* + * If we are relocatable and were loaded at a suitable offset, + * there is no need to do anything and we can just execute in + * place. + */ + *image_addr = (u64)_text; + return EFI_SUCCESS; } else { /* * Else, try a straight allocation at the preferred offset. -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-03-26 16:59 UTC|newest] Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-03-26 16:59 [PATCH 0/2] efi/arm64: execute the kernel in place if possible Ard Biesheuvel 2020-03-26 16:59 ` Ard Biesheuvel 2020-03-26 16:59 ` Ard Biesheuvel [this message] 2020-03-26 16:59 ` [PATCH 1/2] efi/libstub/arm64: avoid copying the kernel unnecessarily Ard Biesheuvel 2020-03-26 16:59 ` [PATCH 2/2] efi/arm64: increase the PE/COFF alignment so the kernel can run in place Ard Biesheuvel 2020-03-26 16:59 ` Ard Biesheuvel 2020-03-28 14:06 ` Arvind Sankar 2020-03-28 14:06 ` Arvind Sankar 2020-03-28 14:10 ` Ard Biesheuvel 2020-03-28 14:10 ` Ard Biesheuvel 2020-03-27 13:19 ` [PATCH 0/2] efi/arm64: execute the kernel in place if possible Jonathan Cameron 2020-03-27 13:19 ` Jonathan Cameron 2020-03-27 16:39 ` Ard Biesheuvel 2020-03-27 16:39 ` Ard Biesheuvel
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