From: Vineet Gupta <vgupta@synopsys.com>
Date: Tue, 25 Oct 2016 17:43:20 +0000 (-0700)
Subject: ARC: module: elide loop to save reference to .eh_frame
X-Git-Tag: v4.9-rc3~11^2~1
X-Git-Url: http://git.cascardo.eti.br/?p=cascardo%2Flinux.git;a=commitdiff_plain;h=d65283f7b695b5d04ca1ab58b6bb41f443b96286

ARC: module: elide loop to save reference to .eh_frame

The loop was really needed in .debug_frame regime where wanted make it
as SH_ALLOC so that apply_relocate_add() would process it. That's not
needed for .eh_frame, so we check this in apply_relocate_add() which
gets called for each section.

Note that we need to save reference to "section name strings" section in
module_frob_arch_sections() since apply_relocate_add() doesn't get that

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---

diff --git a/arch/arc/include/asm/module.h b/arch/arc/include/asm/module.h
index 518222bb3f8e..6e91d8b339c3 100644
--- a/arch/arc/include/asm/module.h
+++ b/arch/arc/include/asm/module.h
@@ -18,6 +18,7 @@
 struct mod_arch_specific {
 	void *unw_info;
 	int unw_sec_idx;
+	const char *secstr;
 };
 #endif
 
diff --git a/arch/arc/kernel/module.c b/arch/arc/kernel/module.c
index 9a2849756022..24bd2ffb90b7 100644
--- a/arch/arc/kernel/module.c
+++ b/arch/arc/kernel/module.c
@@ -30,17 +30,9 @@ int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
 			      char *secstr, struct module *mod)
 {
 #ifdef CONFIG_ARC_DW2_UNWIND
-	int i;
-
 	mod->arch.unw_sec_idx = 0;
 	mod->arch.unw_info = NULL;
-
-	for (i = 1; i < hdr->e_shnum; i++) {
-		if (strcmp(secstr+sechdrs[i].sh_name, ".eh_frame") == 0) {
-			mod->arch.unw_sec_idx = i;
-			break;
-		}
-	}
+	mod->arch.secstr = secstr;
 #endif
 	return 0;
 }
@@ -66,8 +58,10 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
 	Elf32_Addr location;
 	Elf32_Addr sec_to_patch;
 	int relo_type;
+	unsigned int tgtsec;
 
-	sec_to_patch = sechdrs[sechdrs[relsec].sh_info].sh_addr;
+	tgtsec = sechdrs[relsec].sh_info;
+	sec_to_patch = sechdrs[tgtsec].sh_addr;
 	sym_sec = (Elf32_Sym *) sechdrs[symindex].sh_addr;
 	n = sechdrs[relsec].sh_size / sizeof(*rel_entry);
 
@@ -111,6 +105,10 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
 			goto relo_err;
 
 	}
+
+	if (strcmp(module->arch.secstr+sechdrs[tgtsec].sh_name, ".eh_frame") == 0)
+		module->arch.unw_sec_idx = tgtsec;
+
 	return 0;
 
 relo_err: