From: Stafford Horne <shorne@gmail.com> To: LKML <linux-kernel@vger.kernel.org> Cc: Stafford Horne <shorne@gmail.com>, Jonas Bonn <jonas@southpole.se>, Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>, openrisc@lists.librecores.org Subject: [PATCH] openrisc: Fix issue with argument clobbering for clone/fork Date: Mon, 1 Jun 2020 06:24:59 +0900 [thread overview] Message-ID: <20200531212500.826332-1-shorne@gmail.com> (raw) Working on the OpenRISC glibc port I found that sometimes clone was working strange. That the tls data argument sent in r7 was always wrong. Further investigation revealed that the arguments were getting clobbered in the entry code. This patch removes the code that writes to the argument registers. This was likely due to some old code hanging around. This patch fixes this up for clone and fork. This fork clobber is harmless but also useless so remove. Signed-off-by: Stafford Horne <shorne@gmail.com> --- arch/openrisc/kernel/entry.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S index e4a78571f883..c6481cfc5220 100644 --- a/arch/openrisc/kernel/entry.S +++ b/arch/openrisc/kernel/entry.S @@ -1166,13 +1166,13 @@ ENTRY(__sys_clone) l.movhi r29,hi(sys_clone) l.ori r29,r29,lo(sys_clone) l.j _fork_save_extra_regs_and_call - l.addi r7,r1,0 + l.nop ENTRY(__sys_fork) l.movhi r29,hi(sys_fork) l.ori r29,r29,lo(sys_fork) l.j _fork_save_extra_regs_and_call - l.addi r3,r1,0 + l.nop ENTRY(sys_rt_sigreturn) l.jal _sys_rt_sigreturn -- 2.26.2
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From: Stafford Horne <shorne@gmail.com> To: openrisc@lists.librecores.org Subject: [OpenRISC] [PATCH] openrisc: Fix issue with argument clobbering for clone/fork Date: Mon, 1 Jun 2020 06:24:59 +0900 [thread overview] Message-ID: <20200531212500.826332-1-shorne@gmail.com> (raw) Working on the OpenRISC glibc port I found that sometimes clone was working strange. That the tls data argument sent in r7 was always wrong. Further investigation revealed that the arguments were getting clobbered in the entry code. This patch removes the code that writes to the argument registers. This was likely due to some old code hanging around. This patch fixes this up for clone and fork. This fork clobber is harmless but also useless so remove. Signed-off-by: Stafford Horne <shorne@gmail.com> --- arch/openrisc/kernel/entry.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S index e4a78571f883..c6481cfc5220 100644 --- a/arch/openrisc/kernel/entry.S +++ b/arch/openrisc/kernel/entry.S @@ -1166,13 +1166,13 @@ ENTRY(__sys_clone) l.movhi r29,hi(sys_clone) l.ori r29,r29,lo(sys_clone) l.j _fork_save_extra_regs_and_call - l.addi r7,r1,0 + l.nop ENTRY(__sys_fork) l.movhi r29,hi(sys_fork) l.ori r29,r29,lo(sys_fork) l.j _fork_save_extra_regs_and_call - l.addi r3,r1,0 + l.nop ENTRY(sys_rt_sigreturn) l.jal _sys_rt_sigreturn -- 2.26.2
next reply other threads:[~2020-05-31 21:25 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-05-31 21:24 Stafford Horne [this message] 2020-05-31 21:24 ` [OpenRISC] [PATCH] openrisc: Fix issue with argument clobbering for clone/fork Stafford Horne
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