From: Brian Gerst <brgerst@gmail.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org
Cc: Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>,
Thomas Gleixner <tglx@linutronix.de>,
"H . Peter Anvin" <hpa@zytor.com>,
Peter Zijlstra <peterz@infradead.org>,
Brian Gerst <brgerst@gmail.com>
Subject: [PATCH v2 4/6] x86-64: Remove inverse relocations
Date: Tue, 30 Nov 2021 15:55:47 -0500 [thread overview]
Message-ID: <20211130205549.116673-5-brgerst@gmail.com> (raw)
In-Reply-To: <20211130205549.116673-1-brgerst@gmail.com>
Now that the percpu section is not at a fixed address, inverse
relocations (which were needed to offset the effects of relocation on
RIP-relative percpu references) are no longer used.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
arch/x86/boot/compressed/misc.c | 14 +-------------
arch/x86/tools/relocs.c | 9 ---------
2 files changed, 1 insertion(+), 22 deletions(-)
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index a4339cb2d247..5d0ffab408cd 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -215,7 +215,7 @@ static void handle_relocations(void *output, unsigned long output_len,
/*
* Process relocations: 32 bit relocations first then 64 bit after.
- * Three sets of binary relocations are added to the end of the kernel
+ * Two sets of binary relocations are added to the end of the kernel
* before compression. Each relocation table entry is the kernel
* address of the location which needs to be updated stored as a
* 32-bit value which is sign extended to 64 bits.
@@ -225,8 +225,6 @@ static void handle_relocations(void *output, unsigned long output_len,
* kernel bits...
* 0 - zero terminator for 64 bit relocations
* 64 bit relocation repeated
- * 0 - zero terminator for inverse 32 bit relocations
- * 32 bit inverse relocation repeated
* 0 - zero terminator for 32 bit relocations
* 32 bit relocation repeated
*
@@ -243,16 +241,6 @@ static void handle_relocations(void *output, unsigned long output_len,
*(uint32_t *)ptr += delta;
}
#ifdef CONFIG_X86_64
- while (*--reloc) {
- long extended = *reloc;
- extended += map;
-
- ptr = (unsigned long)extended;
- if (ptr < min_addr || ptr > max_addr)
- error("inverse 32-bit relocation outside of kernel!\n");
-
- *(int32_t *)ptr -= delta;
- }
for (reloc--; *reloc; reloc--) {
long extended = *reloc;
extended += map;
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index b27980291ff8..e452b54ddaa1 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -28,7 +28,6 @@ struct relocs {
static struct relocs relocs16;
static struct relocs relocs32;
#if ELF_BITS == 64
-static struct relocs relocs32neg;
static struct relocs relocs64;
#define FMT PRIu64
#else
@@ -959,7 +958,6 @@ static void emit_relocs(int as_text, int use_real_mode)
/* Order the relocations for more efficient processing */
sort_relocs(&relocs32);
#if ELF_BITS == 64
- sort_relocs(&relocs32neg);
sort_relocs(&relocs64);
#else
sort_relocs(&relocs16);
@@ -991,13 +989,6 @@ static void emit_relocs(int as_text, int use_real_mode)
/* Now print each relocation */
for (i = 0; i < relocs64.count; i++)
write_reloc(relocs64.offset[i], stdout);
-
- /* Print a stop */
- write_reloc(0, stdout);
-
- /* Now print each inverse 32-bit relocation */
- for (i = 0; i < relocs32neg.count; i++)
- write_reloc(relocs32neg.offset[i], stdout);
#endif
/* Print a stop */
--
2.31.1
next prev parent reply other threads:[~2021-11-30 20:58 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-30 20:55 [PATCH v2 0/6] x86-64: Stack protector and percpu improvements Brian Gerst
2021-11-30 20:55 ` [PATCH v2 1/6] x86: Remove stack protector test scripts Brian Gerst
2021-11-30 20:55 ` [PATCH v2 2/6] x86-64: Convert stack protector to normal percpu variable Brian Gerst
2021-12-01 9:50 ` David Laight
2021-12-01 14:21 ` Brian Gerst
2021-12-02 22:51 ` Peter Zijlstra
2021-11-30 20:55 ` [PATCH v2 3/6] x86-64: Use relative per-cpu offsets Brian Gerst
2021-11-30 20:55 ` Brian Gerst [this message]
2021-11-30 20:55 ` [PATCH v2 5/6] kallsyms: Remove KALLSYMS_ABSOLUTE_PERCPU Brian Gerst
2021-11-30 20:55 ` [PATCH v2 6/6] percpu: Remove PER_CPU_FIRST_SECTION Brian Gerst
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