From: Laura Abbott <lauraa@codeaurora.org> To: linux@arm.linux.org.uk Cc: dave.martin@linaro.org, Laura Abbott <lauraa@codeaurora.org>, linux-arm-kernel@lists.infradead.org (open list:ARM PORT), linux-kernel@vger.kernel.org (open list) Subject: [PATCH v2] arm: Add unwinding support for division functions Date: Wed, 18 May 2011 10:33:26 -0700 [thread overview] Message-ID: <1305740006-11389-2-git-send-email-lauraa@codeaurora.org> (raw) In-Reply-To: <f16b4b8d7735148b133e23547a7963b3.squirrel@www.codeaurora.org> The software division functions never had unwinding annotations added. Currently, when a division by zero occurs the backtrace shown will stop at Ldiv0 or some completely unrelated function. Add unwinding annotations in hopes of getting a more useful backtrace when a division by zero occurs. Signed-off-by: Laura Abbott <lauraa@codeaurora.org> --- arch/arm/lib/lib1funcs.S | 25 ++++++++++++++++++++----- 1 files changed, 20 insertions(+), 5 deletions(-) diff --git a/arch/arm/lib/lib1funcs.S b/arch/arm/lib/lib1funcs.S index 6dc0648..c562f64 100644 --- a/arch/arm/lib/lib1funcs.S +++ b/arch/arm/lib/lib1funcs.S @@ -35,7 +35,7 @@ Boston, MA 02111-1307, USA. */ #include <linux/linkage.h> #include <asm/assembler.h> - +#include <asm/unwind.h> .macro ARM_DIV_BODY dividend, divisor, result, curbit @@ -207,6 +207,7 @@ Boston, MA 02111-1307, USA. */ ENTRY(__udivsi3) ENTRY(__aeabi_uidiv) +UNWIND(.fnstart) subs r2, r1, #1 moveq pc, lr @@ -230,10 +231,12 @@ ENTRY(__aeabi_uidiv) mov r0, r0, lsr r2 mov pc, lr +UNWIND(.fnend) ENDPROC(__udivsi3) ENDPROC(__aeabi_uidiv) ENTRY(__umodsi3) +UNWIND(.fnstart) subs r2, r1, #1 @ compare divisor with 1 bcc Ldiv0 @@ -247,10 +250,12 @@ ENTRY(__umodsi3) mov pc, lr +UNWIND(.fnend) ENDPROC(__umodsi3) ENTRY(__divsi3) ENTRY(__aeabi_idiv) +UNWIND(.fnstart) cmp r1, #0 eor ip, r0, r1 @ save the sign of the result. @@ -287,10 +292,12 @@ ENTRY(__aeabi_idiv) rsbmi r0, r0, #0 mov pc, lr +UNWIND(.fnend) ENDPROC(__divsi3) ENDPROC(__aeabi_idiv) ENTRY(__modsi3) +UNWIND(.fnstart) cmp r1, #0 beq Ldiv0 @@ -310,11 +317,14 @@ ENTRY(__modsi3) rsbmi r0, r0, #0 mov pc, lr +UNWIND(.fnend) ENDPROC(__modsi3) #ifdef CONFIG_AEABI ENTRY(__aeabi_uidivmod) +UNWIND(.fnstart) +UNWIND(.save {r0, r1, ip, lr} ) stmfd sp!, {r0, r1, ip, lr} bl __aeabi_uidiv @@ -323,10 +333,12 @@ ENTRY(__aeabi_uidivmod) sub r1, r1, r3 mov pc, lr +UNWIND(.fnend) ENDPROC(__aeabi_uidivmod) ENTRY(__aeabi_idivmod) - +UNWIND(.fnstart) +UNWIND(.save {r0, r1, ip, lr} ) stmfd sp!, {r0, r1, ip, lr} bl __aeabi_idiv ldmfd sp!, {r1, r2, ip, lr} @@ -334,15 +346,18 @@ ENTRY(__aeabi_idivmod) sub r1, r1, r3 mov pc, lr +UNWIND(.fnend) ENDPROC(__aeabi_idivmod) #endif Ldiv0: - +UNWIND(.fnstart) +UNWIND(.pad #4) +UNWIND(.save {lr}) str lr, [sp, #-8]! bl __div0 mov r0, #0 @ About as wrong as it could be. ldr pc, [sp], #8 - - +UNWIND(.fnend) +ENDPROC(Ldiv0) -- 1.7.3.3
WARNING: multiple messages have this Message-ID (diff)
From: lauraa@codeaurora.org (Laura Abbott) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2] arm: Add unwinding support for division functions Date: Wed, 18 May 2011 10:33:26 -0700 [thread overview] Message-ID: <1305740006-11389-2-git-send-email-lauraa@codeaurora.org> (raw) In-Reply-To: <f16b4b8d7735148b133e23547a7963b3.squirrel@www.codeaurora.org> The software division functions never had unwinding annotations added. Currently, when a division by zero occurs the backtrace shown will stop at Ldiv0 or some completely unrelated function. Add unwinding annotations in hopes of getting a more useful backtrace when a division by zero occurs. Signed-off-by: Laura Abbott <lauraa@codeaurora.org> --- arch/arm/lib/lib1funcs.S | 25 ++++++++++++++++++++----- 1 files changed, 20 insertions(+), 5 deletions(-) diff --git a/arch/arm/lib/lib1funcs.S b/arch/arm/lib/lib1funcs.S index 6dc0648..c562f64 100644 --- a/arch/arm/lib/lib1funcs.S +++ b/arch/arm/lib/lib1funcs.S @@ -35,7 +35,7 @@ Boston, MA 02111-1307, USA. */ #include <linux/linkage.h> #include <asm/assembler.h> - +#include <asm/unwind.h> .macro ARM_DIV_BODY dividend, divisor, result, curbit @@ -207,6 +207,7 @@ Boston, MA 02111-1307, USA. */ ENTRY(__udivsi3) ENTRY(__aeabi_uidiv) +UNWIND(.fnstart) subs r2, r1, #1 moveq pc, lr @@ -230,10 +231,12 @@ ENTRY(__aeabi_uidiv) mov r0, r0, lsr r2 mov pc, lr +UNWIND(.fnend) ENDPROC(__udivsi3) ENDPROC(__aeabi_uidiv) ENTRY(__umodsi3) +UNWIND(.fnstart) subs r2, r1, #1 @ compare divisor with 1 bcc Ldiv0 @@ -247,10 +250,12 @@ ENTRY(__umodsi3) mov pc, lr +UNWIND(.fnend) ENDPROC(__umodsi3) ENTRY(__divsi3) ENTRY(__aeabi_idiv) +UNWIND(.fnstart) cmp r1, #0 eor ip, r0, r1 @ save the sign of the result. @@ -287,10 +292,12 @@ ENTRY(__aeabi_idiv) rsbmi r0, r0, #0 mov pc, lr +UNWIND(.fnend) ENDPROC(__divsi3) ENDPROC(__aeabi_idiv) ENTRY(__modsi3) +UNWIND(.fnstart) cmp r1, #0 beq Ldiv0 @@ -310,11 +317,14 @@ ENTRY(__modsi3) rsbmi r0, r0, #0 mov pc, lr +UNWIND(.fnend) ENDPROC(__modsi3) #ifdef CONFIG_AEABI ENTRY(__aeabi_uidivmod) +UNWIND(.fnstart) +UNWIND(.save {r0, r1, ip, lr} ) stmfd sp!, {r0, r1, ip, lr} bl __aeabi_uidiv @@ -323,10 +333,12 @@ ENTRY(__aeabi_uidivmod) sub r1, r1, r3 mov pc, lr +UNWIND(.fnend) ENDPROC(__aeabi_uidivmod) ENTRY(__aeabi_idivmod) - +UNWIND(.fnstart) +UNWIND(.save {r0, r1, ip, lr} ) stmfd sp!, {r0, r1, ip, lr} bl __aeabi_idiv ldmfd sp!, {r1, r2, ip, lr} @@ -334,15 +346,18 @@ ENTRY(__aeabi_idivmod) sub r1, r1, r3 mov pc, lr +UNWIND(.fnend) ENDPROC(__aeabi_idivmod) #endif Ldiv0: - +UNWIND(.fnstart) +UNWIND(.pad #4) +UNWIND(.save {lr}) str lr, [sp, #-8]! bl __div0 mov r0, #0 @ About as wrong as it could be. ldr pc, [sp], #8 - - +UNWIND(.fnend) +ENDPROC(Ldiv0) -- 1.7.3.3
next prev parent reply other threads:[~2011-05-18 17:34 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-05-13 1:24 [PATCH] arm: Add unwinding support for division functions Laura Abbott 2011-05-13 1:24 ` Laura Abbott 2011-05-17 15:07 ` Dave Martin 2011-05-17 15:07 ` Dave Martin 2011-05-18 16:39 ` Laura Abbott 2011-05-18 16:39 ` Laura Abbott 2011-05-18 17:33 ` Laura Abbott [this message] 2011-05-18 17:33 ` [PATCH v2] " Laura Abbott 2011-05-19 11:10 ` Dave Martin 2011-05-19 11:10 ` Dave Martin
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