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From: Arvind Sankar <nivedita@alum.mit.edu>
To: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Jonathan Corbet <corbet@lwn.net>,
	Ard Biesheuvel <ardb@kernel.org>
Cc: linux-efi@vger.kernel.org, x86@kernel.org, linux-doc@vger.kernel.org
Subject: [PATCH 2/8] efi/x86: Allocate the GDT pointer on the stack
Date: Thu, 30 Jan 2020 15:04:34 -0500
Message-ID: <20200130200440.1796058-3-nivedita@alum.mit.edu> (raw)
In-Reply-To: <20200130200440.1796058-1-nivedita@alum.mit.edu>

The GDT pointer isn't needed after loading it into GDTR, so there is no
need to dynamically allocate it.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
---
 arch/x86/boot/compressed/eboot.c | 19 ++++++-------------
 1 file changed, 6 insertions(+), 13 deletions(-)

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index f89caae60057..a0a2fd0528af 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -713,7 +713,7 @@ struct boot_params *efi_main(efi_handle_t handle,
 			     efi_system_table_t *sys_table_arg,
 			     struct boot_params *boot_params)
 {
-	struct desc_ptr *gdt = NULL;
+	struct desc_ptr gdt;
 	struct setup_header *hdr = &boot_params->hdr;
 	efi_status_t status;
 	struct desc_struct *desc;
@@ -754,15 +754,8 @@ struct boot_params *efi_main(efi_handle_t handle,
 
 	setup_quirks(boot_params);
 
-	status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, sizeof(*gdt),
-			     (void **)&gdt);
-	if (status != EFI_SUCCESS) {
-		efi_printk("Failed to allocate memory for 'gdt' structure\n");
-		goto fail;
-	}
-
-	gdt->size = 0x800;
-	status = efi_low_alloc(gdt->size, 8, (unsigned long *)&gdt->address);
+	gdt.size = 0x800;
+	status = efi_low_alloc(gdt.size, 8, (unsigned long *)&gdt.address);
 	if (status != EFI_SUCCESS) {
 		efi_printk("Failed to allocate memory for 'gdt'\n");
 		goto fail;
@@ -794,8 +787,8 @@ struct boot_params *efi_main(efi_handle_t handle,
 		goto fail;
 	}
 
-	memset((char *)gdt->address, 0x0, gdt->size);
-	desc = (struct desc_struct *)gdt->address;
+	memset((char *)gdt.address, 0x0, gdt.size);
+	desc = (struct desc_struct *)gdt.address;
 
 	/* The first GDT is a dummy. */
 	desc++;
@@ -879,7 +872,7 @@ struct boot_params *efi_main(efi_handle_t handle,
 	}
 
 	raw_local_irq_disable();
-	native_load_gdt(gdt);
+	native_load_gdt(&gdt);
 
 	return boot_params;
 fail:
-- 
2.24.1


  parent reply index

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-30 20:04 [PATCH 0/8] Remove 64-bit GDT setup in efi_main + doc fixes Arvind Sankar
2020-01-30 20:04 ` [PATCH 1/8] efi/x86: Use C wrapper instead of inline assembly Arvind Sankar
2020-01-30 20:04 ` Arvind Sankar [this message]
2020-01-30 20:04 ` [PATCH 3/8] efi/x86: Factor GDT setup code into a function Arvind Sankar
2020-01-30 20:04 ` [PATCH 4/8] efi/x86: Only setup the GDT for 32-bit kernel Arvind Sankar
2020-01-30 20:04 ` [PATCH 5/8] efi/x86: Allocate only the required 32 bytes for the GDT Arvind Sankar
2020-01-30 20:04 ` [PATCH 6/8] efi/x86: Change __KERNEL_{CS,DS} to __BOOT_{CS,DS} Arvind Sankar
2020-01-30 20:04 ` [PATCH 7/8] Documentation/x86/boot: Clarify segment requirements for EFI handover Arvind Sankar
2020-01-31 19:24   ` Arvind Sankar
2020-01-30 20:04 ` [PATCH 8/8] Documentation/x86/boot: Correct segment requirements for 64-bit boot Arvind Sankar
2020-01-31  8:42 ` [PATCH 0/8] Remove 64-bit GDT setup in efi_main + doc fixes Ard Biesheuvel
2020-01-31  9:31   ` Ard Biesheuvel
2020-01-31 19:10     ` Arvind Sankar
2020-02-02 17:13 ` [PATCH v2 0/7] x86/efi,boot: GDT handling cleanup/fixes Arvind Sankar
2020-02-02 17:13   ` [PATCH v2 1/7] x86/boot: Remove KEEP_SEGMENTS support Arvind Sankar
2020-02-02 17:13   ` [PATCH v2 2/7] efi/x86: Don't depend on firmware GDT layout Arvind Sankar
2020-02-02 17:54     ` Ard Biesheuvel
2020-02-02 18:18       ` Arvind Sankar
2020-02-02 17:13   ` [PATCH v2 3/7] x86/boot: Reload GDTR after copying to the end of the buffer Arvind Sankar
2020-02-02 17:13   ` [PATCH v2 4/7] x86/boot: Clear direction and interrupt flags in startup_64 Arvind Sankar
2020-02-02 17:13   ` [PATCH v2 5/7] efi/x86: Remove GDT setup from efi_main Arvind Sankar
2020-02-02 17:13   ` [PATCH v2 6/7] x86/boot: GDT limit value should be size - 1 Arvind Sankar
2020-02-02 17:13   ` [PATCH v2 7/7] x86/boot: Micro-optimize GDT loading instructions Arvind Sankar
2020-02-02 18:01   ` [PATCH v2 0/7] x86/efi,boot: GDT handling cleanup/fixes Ard Biesheuvel

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