| Message ID | 20191025095605.17673-1-mark.corbin@embecosm.com |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [1/1] package/libsigsegv: fix macro expansion error for RISC-V with musl | expand |
On Fri, 25 Oct 2019 10:56:05 +0100 Mark Corbin <mark.corbin@embecosm.com> wrote: > The expansion of the SIGSEGV_FAULT_STACKPOINTER macro fails when > building for RISC-V with musl because REG_SP is not defined (it is > defined for glibc). This patch just replaces REG_SP with the > numerical register offset (which is 2 for the stack pointer). REG_SP is defined in musl in: https://git.musl-libc.org/cgit/musl/tree/arch/riscv64/bits/reg.h So I'm not sure I'm following the reasoning here. Thomas
Hello Thomas On 25/10/2019 20:43, Thomas Petazzoni wrote: > On Fri, 25 Oct 2019 10:56:05 +0100 > Mark Corbin <mark.corbin@embecosm.com> wrote: > >> The expansion of the SIGSEGV_FAULT_STACKPOINTER macro fails when >> building for RISC-V with musl because REG_SP is not defined (it is >> defined for glibc). This patch just replaces REG_SP with the >> numerical register offset (which is 2 for the stack pointer). > REG_SP is defined in musl in: > > https://git.musl-libc.org/cgit/musl/tree/arch/riscv64/bits/reg.h > > So I'm not sure I'm following the reasoning here. There are register definitions in reg.h, but these are not the ones used by the signal header files in musl (arch/<build arch>/bits/signal.h). If you want to index the registers array in the ucontext_t or mcontext_t structures using a register name it needs to be defined at the top of bits/signal.h (see the musl i386, m68k, x32 and x86_64 architectures). Alternatively, for architectures that do not define register names in the musl signal.h file, the registers array is indexed in libsigsegv using a numeric offset (see libsigsegv-2.12/src/fault-linux-mips.h for example). There are two options to fix the current libsigsegv build issue for RISC-V with musl (REG_SP undefined), either a) patch musl to add a definition for REG_SP to signal.h or b) change REG_SP to a numeric value of 2 in libsigsegv-2.12/src/fault-linux-riscv64.h (as proposed by this patch). Mark
diff --git a/package/libsigsegv/0005-Fix-macro-expansion-error-when-building-for-RISC-V-w.patch b/package/libsigsegv/0005-Fix-macro-expansion-error-when-building-for-RISC-V-w.patch new file mode 100644 index 0000000000..6906e04b1d --- /dev/null +++ b/package/libsigsegv/0005-Fix-macro-expansion-error-when-building-for-RISC-V-w.patch @@ -0,0 +1,29 @@ +From 3da9e4a8aea252143ab567678722c739793cfeb7 Mon Sep 17 00:00:00 2001 +From: Mark Corbin <mark.corbin@embecosm.com> +Date: Fri, 25 Oct 2019 10:16:54 +0100 +Subject: [PATCH] Fix macro expansion error when building for RISC-V with + musl + +The expansion of the SIGSEGV_FAULT_STACKPOINTER macro fails when +building for RISC-V with musl because REG_SP is not defined (it is +defined for glibc). This patch just replaces REG_SP with the +numerical register offset (which is 2 for the stack pointer). + +Signed-off-by: Mark Corbin <mark.corbin@embecosm.com> +--- + src/fault-linux-riscv64.h | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/src/fault-linux-riscv64.h b/src/fault-linux-riscv64.h +index 14831bf..7fee4d3 100644 +--- a/src/fault-linux-riscv64.h ++++ b/src/fault-linux-riscv64.h +@@ -26,4 +26,4 @@ + glibc/sysdeps/unix/sysv/linux/riscv/bits/sigcontext.h + start with the same block of 32 general-purpose registers. */ + +-#define SIGSEGV_FAULT_STACKPOINTER ((ucontext_t *) ucp)->uc_mcontext.__gregs[REG_SP] ++#define SIGSEGV_FAULT_STACKPOINTER ((ucontext_t *) ucp)->uc_mcontext.__gregs[2] +-- +2.19.1 +
The expansion of the SIGSEGV_FAULT_STACKPOINTER macro fails when building for RISC-V with musl because REG_SP is not defined (it is defined for glibc). This patch just replaces REG_SP with the numerical register offset (which is 2 for the stack pointer). Fixes: http://autobuild.buildroot.net/results/8d6cade2562404b9800736a3b9a2beada98bda88 Signed-off-by: Mark Corbin <mark.corbin@embecosm.com> --- ...ion-error-when-building-for-RISC-V-w.patch | 29 +++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 package/libsigsegv/0005-Fix-macro-expansion-error-when-building-for-RISC-V-w.patch