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[PATCH] uml: use correct register file size everywhere

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This patch uses MAX_REG_NR consistently to refer to the register file size.
 FRAME_SIZE isn't sufficient because on x86_64, it is smaller than the
ptrace register file size.  MAX_REG_NR was introduced as a consistent way
to get the number of registers, but wasn't used everywhere it should be.

When this causes a problem, it makes PTRACE_SETREGS fail on x86_64 because
of a corrupted segment register value in the known-good register file.  The
patch also adds a register dump at that point in case there are any future
problems here.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jeff Dike
2007-03-26 21:32:25 -08:00
committed by Linus Torvalds
parent 7632fc8f80
commit b92c4f922b
5 changed files with 15 additions and 14 deletions
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6
arch/um/os-Linux/skas/process.c
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@@ -67,7 +67,7 @@ void wait_stub_done(int pid, int sig, char * fname)
if((n < 0) || !WIFSTOPPED(status) ||
(WSTOPSIG(status) != SIGUSR1 && WSTOPSIG(status) != SIGTRAP)){
unsigned long regs[HOST_FRAME_SIZE];
unsigned long regs[MAX_REG_NR];
if(ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
printk("Failed to get registers from stub, "
@@ -76,7 +76,7 @@ void wait_stub_done(int pid, int sig, char * fname)
int i;
printk("Stub registers -\n");
for(i = 0; i < HOST_FRAME_SIZE; i++)
for(i = 0; i < ARRAY_SIZE(regs); i++)
printk("\t%d - %lx\n", i, regs[i]);
}
panic("%s : failed to wait for SIGUSR1/SIGTRAP, "
@@ -328,7 +328,7 @@ void userspace(union uml_pt_regs *regs)
int copy_context_skas0(unsigned long new_stack, int pid)
{
int err;
unsigned long regs[HOST_FRAME_SIZE];
unsigned long regs[MAX_REG_NR];
unsigned long fp_regs[HOST_FP_SIZE];
unsigned long current_stack = current_stub_stack();
struct stub_data *data = (struct stub_data *) current_stack;